Cognitive and Social Cognitive Development of Depressed Children and Adolescents MARIA KOVACS , PH.D . ,
AN D
DAVID GOLDSTON , PH.D.
Abstract. Depressed j uveniles show evide nce of functional impairment in various cog nitive and social domains. Actual school performance seems to be more co nsistently affected by depression than cog nitive and intellect ual abilities . In addition, depressed youth appear to be less socially adept than nondepressed peers, although depression does not consistently impair social-cog nitive abilities . Indications that depressed youth show mild decl ines in tested verbal perform ance over time and that residual problems in social functionin g persist after symptomatic recovery suggest that major depre ssion may have negative effec ts on development in childhood. J, Am . Acad . Child Adolesc . Psychiatry, 1991 ,30, 3:388-392 . Key Words: cog nitive development, social deve lopment, depression in childhood . There is now convincing evidence that school-aged children and adolescents do suffer from depressive disorders and that these disorders disrupt young patients ' function ing in a variety of areas (Kovacs, 1989, Puig-Antich , 1987). One important question that remains is whether, and to what extent, childhood-onset affective illness has deleterious consequences on normal development (Rutter , 1986). Longitudinal study is the most suitable way to investigate these developmental issues. However, cross-sectional study can also provide pertinent information if age-specific normative data are available that enable inferences about developmental lags. The purpose of the present article is to review the research evidence on the development of depressed children and adolescents . The focus is on two domains of development that have received much attention recently , namely, cognit ive development and social-co gnitive development. Cognitive development has been commonly studied as intellectual performance, problem -solving ability, and academic achievement. Social-cognitive development has been examined in terms of actual social behavior, interpersonal problem-solving ability, and social concept formation. The concept of " development" reflects the assumption that functioning in cognitive and social-cognit ive domains progress with the age and maturity of the child , either as qualitative "leaps" or quantitative gains. In assessing these developmental domains, it is important to distinguish between abilities and skills on the one hand , and actual performance and behavior on the other hand . The presence of a psychiatric disorder Accepted November 8. 1990 . Dr. Kovacs is with the Western Psychiatric 1nstitute and Clinic. University of Pittsburgh School of Medicine. Dr. Goldston is with the Department of Psychiatry and Behavioral Medicine, Bowman Gray School of Medicine of Wake Forest University. Preparation of this paper was supported by Grant No . MH-33990 fr om the National Institute of Mental Health , Health and Human Services Administration and a grant fro m the W. T. Grant Foundation. The authors would like to dedicate this article to the memory of Joaquim Puig-Antich, M.D .• fr iend and colleague. Reprint requests to Dr . Kovacs. Western Psychiatric Institute and Clinic. 3811 O'Hara Street. Pittsburgh. PA 15213. 0890 -8567/91/3003 -0388$03 .00/0 © 1991 by the American Academy of Child and Adolescent Psychiatry .
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may impair only perform ance but have no obvious effect on the abilities and skills that are necessary to carry out the performance , or it may disrupt the developmental progression both of abilities and accompanying behav ior. To appreciate the potenti ally negative effects of the depressive disorders in the juvenile years, their clinic al features are briefly reviewed , and how various feature s may interfere with cognitive and social functioning is discussed . The available research eviden ce regarding their effect s on children' s development is then summarized .
Clinical Features of Childhood-Onset Depressive Disorders Depressive disorders have been diagnosed even among preschoolers (e.g. , Kashan i and Carlson , 1985) accord ing to operational criteria , such as the Research Diagnost ic Criteria (Spitzer et a!. , 1978) and the DSM-ll/ . An episode of major depression in childhood lasts about 10 months on average, may have psychotic or melancholic features , and rarely occurs in a "pure" form (Kovacs and Gatsonis, 1989; Puig-Antich, 1987; Strober and Carlson, 1982). In fact , depressed youth often have multiple concurrent psychi atric problems, with anxiety disorders and conduct disorders being among the most prevalent comorbid conditions (Kovacs et ai., 1988 , 1989 ; Puig-Antich , 1982 ). Although major depression in childhood is associated with a high rate of recovery , youngsters with such a history are at a very high risk for developing a recurrent episode of major depres sion and are at increased risk for bipolar disorder (Kovacs and Gatsonis, 1989; Strober and Carlson, 1982). Children and adolescents can also manifest dysthymic disorder (or minor depression ), which is a presumably less severe although a protracted affective disturbance . Dysthymic disorder in childhood lasts over 3'12 years on average . It has many features in common with major depression, including a high rate of eventual recovery . Juvenile-onset dysthymic disorde r is also associated with a high rate of comorbid psychiatric disorders, an increased risk for major depression , and a risk for bipolar outcome (Kovacs and Gatsonis, 1989). When the syndrome of major depres sion is exam ined from a developmental perspective, school-age and adolescent patients appear to show some age-associated variations in l.Am .Acad. Chil d Adolesc . Psychiatry, 30:3, Ma y /99/
LONGITUDINAL RESEARCH : COGNITIVE DEVELOPMENT
symptomatology. Specifically, complaints of hypersomnia and anhedonia appear to be more characteristic of older children; whereas, hyposomnia, separation anxiety, and somatic complaints are more frequent among younger patients (Kovacs and Gatsonis, 1989; Ryan et al., 1987). Nonetheless, a search for developmental-stage mediators of symptom expression has not proven to be enlightening. That is, using a Piagetian perspective, children at various stages of development did not show the hypothesized differences in symptoms and disorder characteristics (Kovacs and Paulauskas, 1984). In spite of isolated age-associated variations, the prototypical picture of major depression generally appears to be similar across age groups.
Possible Effects of Depression on Cognitive and Social Functioning and Development There are a number of ways in which depressive disorders may have detrimental short-term and long-term effects on cognitive and social functioning and development. The negative effects could derive from specific depressive symptoms , the overall impact and length of the episodes, and the combination of symptom characteristics and disorder duration. Certain depressive symptoms may be particularly disruptive of cognitive functioning. For instance, prolonged difficulties with concentration, anhedonia, and psychomotor retardation could affect intellectual and academic achievement. Attentional problems that often characterize depressive illness may interfere with the process of mastering new, unfamiliar, or complex academic problems . Reduced motivation may make it difficult to engage in learning tasks that are demanding or those that require "effortful" processing (Cohen et al., 1982). Psychomotor retardation may slow the rate of acquisition and consolidation of information for long-term memory and also may cause depressed students to perform poorly on timed tests. Academic failure, in turn, is likely to undermine further youngsters' self-esteem and contribute to subsequent negative learning experiences. Some depressive symptoms may also have adverse effects on social cognition and social problem-solving skills. For instance, in the presence of social withdrawal and anhedonia, normal interactions with peers and adults are precluded . This may appear as a failure to show proper initiative and reciprocity in interpersonal situations . The irritability of depressed youths and the nonverbal manifestations of depression (e.g ., avoidance of eye contact) may be perceived by others as noxious, may discourage overtures and attention from other individuals, and thus may increase the youngsters' social isolation . Depressed youth therefore may be deprived of the social interactions that reinforce ageappropriate social skills and are necessary for the continued development of the understanding and management of interpersonal situations. A youngster suffering from major depression or dysthymia of even a l-year duration is impaired for a significant portion of his or her age span . Moreover, the dysfunction occurs during a stage of life that ordinarily is associated with the rapid acquisition of new information and the unl .Am. Acad. Child Adolesc. Psychiatry, 30:3, May 1991
folding of increasingly sophisticated problem-solving strategies. It is likely that lengthy periods of major affective disorder in childhood interfere with or delay such normal developmental progression; namely, the illness disrupts the transactions with the environment that facilitate learning, development, and the utilization of any newly acquired information (e.g. , Gordon, 1988). For instance, an l l-yearold boy who is depressed for 1 year or longer may miss out on important cognitive and social learning experiences during his period of symptomatology. Relative to his or her peers, he may consequently be developmentally delayed in the cognitive and social domains when his depression remits. The severity, persistence, and long-term consequences of such delays also could be mediated by the patients' developmental stage among other factors. For example, cognitively and socially less sophisticated younger children may be rendered more dysfunctional by their depressions . They may have more trouble "catching up" to developmental milestones than older youths who had had more extensive coping repertoires before depression onset.
Empirical Studies of Depression and Development To determine the cognitive and social-cognitive functioning of depressed juveniles, investigators have assessed abilities and skills (using intelligence tests and analogue tests of social problem solving) as well as actual school performance and social behavior. Although almost all of the information derives from cross-sectional studies, it is possible to make some inferences about the effects of depression on development when normative data are available. To start with, the overall intellectual potential of depressed juveniles is generally comparable with that of the normal population (e.g ., Kashani et al., 1983; Weinberg et al., 1973; Weiner and Pfeffer, 1986), suggesting no substantive prior delay in this domain. However, depression still appears to have some impact, although its effect on global intellectual performance may be relatively weak. This is suggested by the modest although statistically significant negative associations between severity of depression (assessed by peer nomination, self-rating, or self-report) and various measures of intelligence in studies of large, school based, or epidemiological samples (Lefkowitz and Tesiny, 1985; McGee et al. , 1986; Tesiny et al., 1980). There are also some indications that depression may selectively impair specific cognitive functions . In at least two studies of students classified as depressed and nondepressed, based on self-rated symptom scales, depression was associated with impaired performance on tasks requiring attention, coordination, and psychomotor speed but did not adversely affect verbal skills and verbal intellectual performance (Kaslow et al. , 1983; 1984). In other studies, however, depressed juveniles performed equally well on tasks of verbal and nonverbal intelligence or manifested a tendency toward a somewhat lower verbal than performance IQ (Brumback et al., 1977, 1980; Kashani et al., 1983; Weinberg et al., 1973; Weiner and Pfeffer, 1986). The data are more consistent concerning the relationship of depression to scholastic achievement and academic performance (e.g., Brumback et al., 1980; Lefkowitz and Tes389
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iny, 1985; Nolen-Hoeksema et al., 1986; Puig-Antich et al., 1985a; Strauss et al., 1984; Tesiny et al., 1980; Weinberg et al., 1973). This body of literature indicates that youngsters who report depressive symptoms, who are viewed by their peers as depressed, or whose depression is detected by psychiatric examination tend to perform poorly in school and have various academic difficulties. Additionally, increasing severity of depression among students is associated with poorer performance on standardized achievement tests, and teachers view depressed children as doing less well academically than their nondepressed peers. The social cognitive abilities thought to be necessary for appropriate social functioning appear to be relatively unaffected by depression. For example, according to several school-based studies that defined depression by self-rating scales and used analogue social problem-solving tasks, depressed youngsters were generally as capable as their nondepressed peers of providing cognitive solutions to interpersonal problems (Mullins et al., 1985). Additionally, when multiple aspects of interpersonal problem solving were examined, depressed children performed as well as nondepressed peers on the majority of tasks (Sacco and Graves, 1984). . On the other hand, symptomatic youngsters do show impaired social-interpersonal behaviors. When they are observed in actual situations, depressed children are consistently described as less socially adept than nondepressed peers; they also are preferred less often as play- or workmates (Altmann and Gotlib, 1988; Blechman et al., 1986). Compared both to nondepressed "neurotic" and normal age mates, clinically depressed children have worse peer relationships, including less peer contact and fewer, if any, best friends (Puig-Antich et al., 1985a). Studies that used peer nomination techniques in classroom settings also have consistently revealed that children who view themselves as depressed are more rejected, more isolated, less liked, and less assertive than nondepressed schoolmates (e.g., Altmann and Gotlib, 1988; Kennedy et al., 1989; Tesiny et al., 1980). In summary, the results of cross-sectional studies suggest that depression in the juvenile years is associated with deficits in cognitive and social functioning. These effects appear most consistenly with observable behaviors: namely, actual school performance and social interactions. In contrast, depression appears to be less disruptive of developmentally mediated "internal" abilities and potentials. However, these cross-sectional data do not provide information as to whether the children's school and social problems preceded their depression. Cross-sectional studies also do not shed light on whether the impairments are merely contemporaneous with the depression, if they persist over time, or if the impairments have consequences for later functioning. Longitudinal study provides the most appropriate vehicle for examining such issues in developmental psychopathology. While longitudinal study may not completely illuminate the nature of the relationship between different variables over time, it can serve to establish temporal patterns from which causal relationships may at least be inferred. Unfortunately, little information exists currently on the 390
long-term cognitive and social-cognitive development of depressed juveniles. However, there are some indications that children with major depressive illness may be at risk for continued cognitive and social problems that may persist even after symptomatic recovery. This information derives primarily from two studies: a 4-month follow-up of recovered cases by Puig-Antich and associates (l985b) and the authors' own ongoing longitudinal investigation of the nosology and course of childhood-onset depressions. In the authors' own study (which is currently in its 12th year and is described elsewhere in detail, see Kovacs et al., 1984; Kovacs and Gatsonis, 1989), 8- to 13-year-old clinically referred children, who met DSM-III criteria for depressive disorder, were assessed repeatedly with a comprehensive battery of tests and psychiatric measures. The battery included the yearly administration of a short version of the WISC-R (Vocabulary and Block Design subtests) (Wechsler, 1974); school records were also routinely obtained. Preliminary results suggest both temporary and longer term negative correlates of affective illness; the diagnosis of major depression seemed to be most consistently associated with performance deficits (Kovacs et al., 1990, submitted for publication). Children showed lower nonverbal intellectual performance during their index episode of major depression, compared with when they were no longer in the episode. In contrast, verbal performance during the episode of major depression was not impaired (compared with when not in the depressive episode), paralleling the bulk of previous findings from cross-sectional studies. For dysthymic children, no performance differences were evident as a function of being in or out of the episode of dysthymia. However, longitudinal analyses revealed mild declines in verbal intellectual performance over subsequent years among children with major depression or dysthymia, which may partly
reflect a disruption in the acquisition of verbal skills. The decline in verbal intellectual performance over time was also influenced by sociodemographic factors but could not be attributed to the presence of comorbid conduct disorders. In addition, major depressive disorder appears to have enduring effects on school performance. Puig-Antichand associates' (l985b) follow-up of depressed children, who have been in remission for at least 4 months, revealed only a trend toward improvement in school functioning. In the present author's study, it was found that children with a longer history of depression received poorer grades over time, and that the proportion of time a child had had a major depression during the school year was negatively related to grade point average (Kovacs et al., 1990, submitted for publication) . Consistent with the results of cross-sectional studies, the present authors also found that, with continued observation, the depressed patients showed progression on "Piagetian" tasks of social cognition, although their rate of development may have been somewhat delayed. In terms of actual social behavior, the follow-up of Puig-Antich and associates (1985b), however, suggests that some impairment persists in actual peer relationships even after sustained recovery from the depression. l.Am.Acad. Child Adolesc. Psychiatry, 30:3, May 1991
LONGITUDINAL RESEARCH : COGNITIVE DEVELOPMENT
Discussion In the present article, the issue as to whether depre ssive disorders in the juvenile years disrupt or interfere with cognitive and social cognitive development is addressed. These two domains of development have come to attract increased attention partly because of the salience of cognitive and social-cognitive factors in adaptation during the school-age years and also because recent theories have implicated cognitive and social factors in the etiology of depression. According to currently available data, there do not appear to be any obvious preexisting impairments in depressed children's intellectual functioning. However, cross-sectional studies provide some evidence that the presence of depressive symptoms or diagnosable depression does have a negative impact in certain cognitive and social areas. The deficits in functioning are most compelling in investigations of actual behavior. Studies of cognitive abilities or potentials using various tests have yielded less consistent findings. However, the scarcity of developmental-stage specific normative information on social cognition and functioning leaves open the possibility that some depression-associated social deficits may have preceded the disorder. Longitudinal study also revealed deficits in nonverbal cognitive and intellectual performance in association with depression, thereby supporting and extending the results of several cross-sectional projects . However, what was not evident from cross-sectional studies was that the impairments in nonverbal intellectual performance are temporary, and that , similar to "state markers ," they resolve after the depressive episodes remit. It also was not evident from cross-sectional studies that children with depressive disor ders may show increasing deficits in verbal functioning and continue to be socially impaired over time. In summary then, it appears that deficits in actual intellectual and social performance or behavior do not necessarily reflect deficits in abilities and potentials. Nonetheless, depression in childhood may have long-term negat ive effects because it may significantly disrupt and interfere with the process of continued learning and social adaptation. It would also seem that persistent disruptions in age-appropriate behaviors can lay the groundwork for subsequent developmental delays. Although further longitudinal studies are needed to obtain a more coherent picture of the developmental patterns of depressed juveniles, associated methodological problem s make it difficult to totally disentangle temporal relationships. For example, it appears logical that aspects of the depressive syndrome (e.g., attentional and motivational problems, psychomotor retardation) could precipitate contemporaneous performance deficits on nonverbal tasks. Such deficits have been clearly demonstrated in adults and have been attributed, in part, to some generalized deficit in a central motivational state (Cohen et aI. , 1982). Depression can also be expected to interfere with the process of learning and education and thereby disrupt the continuous acquisition of verbal skills over time. The temporal patterns observed with regard to the behavior of depressed children support such inferences. However, temporal precedence does not necessarily mean causality . Causal relationships can only l.Am . Acad. Child Adolesc. Psychiatry , 30:3, May 1991
be tested within experimental settings that permit the manipulation of certain variables, while important sources of variation are controlled. Such investigations are, therefore, needed to verify the temporal-causal trends that emerge from studies of the cognitive and social functioning of depressed youth. Studies also are needed to determine the effects of interventions that focus on reversing depression-associated deficits or ameliorating the functional consequences of these disorders. Such efforts could be justified by data from crosssectional studies suggesting that whereas cognitive and social behavior may be impaired during the depression, potential skills and abilities needed to execute such behaviors remain relatively intact, at least in the short run. Therefore , remediation of dysfunctional behaviors that are evident during the depression could possibly forestall subsequent developmental delays or prevent the accumulation of cognitive and social failure experiences.
References Altmann , E. O. & Gotlib, I. H. (1988), The social behavior of depressed children: an observational study . J. Abnorm. Child Psychol ., 16:29-44. Blechman , E. A., McEnroe, M. J. , Carella , E. T. & Audette , D . P. (1986 ), Childhood competence and depression. J. Abn orm , Psychol.. 95:223-227 . Brumba ck, R. A. , Dietz-Schmidt, S. G. & Weinberg, W . A. (1977), Depres sion in children referred to an educational diagnostic center: diagnosis and treatment and analysis of criteria and literature review . Diseases of the Nervous System, 38:529-535 . - - Jackoway, M . K . & We inberg , W . A . (1980), Relation of intelligence to childhood depre ssion in children referred to an educational diagnostic center. Percept . Mot. Skills. 50: 11-17. Cohen , R. M., Weingartner, H., Smallberg, S. A., Pickar, D. & Murph y, D. L. (1982) , Effort and cognition in depression . Arch. Gen. Psychiatry, 39:593-597 . Gordon, D. E. (1988), Formal operations and interpersonal and affective disturbances in adole scents. In: Developmental Psy chopathology and Its Treatment . New Directions for Child Development, No. 39, eds. E. D . Nannis & P. A. Cowan. San Francisco: JosseyBass, pp. 51-73. Kashani, J. H. & Carlson, G . A. (1985), Major depressive disorder in a preschooler. J. Am. Acad. Child Psychiatry, 24:490-494 . - - McGee, R. 0 ., Clarkson, S. E. et al. (1983), Depression in a sample of 9-year-old children . Prevalence and associated characteristics . Arch . Gen . Psychiatry. 40 :1217-1223 . Kaslow , N. 1. , Tanenbaum, R. L. , Abramson, L. Y ., Peterson , C . & Seligman, M. E. P. (1983), Problem-solving deficits and depressive symptoms among children . J . Abnorm. Child Psychol ., I I :497- 50 I. - - Rehm, L. P. & Siegel, A. W . (1984 ), Social-cognitive and cognitive correlates of depre ssion in children . J, Abnorm. Child Psychol .. 12:605-620. Kenned y , E., Spen ce , S . H. & Hensley, R. (1989) , An examination of the relationship between c hildhood depression and social com-
petence amongst primary school children . J . Child. Psychol . Psychiatry, 30:561-573 . Kovacs , M. (1989), Affective disorders in children and adolescents . Am . Psychol. , 44:209-215 . - - Paulauskas, S. L. (1984) , Developmental stage and the expression of depressive disorders in children: an empirical analysis . In: Childhood Depression. New Directions for Child Development, No . 26 , eds. D. Cicchetti & K. Schneider-Rosen. San Francisco: Jos seyBass , pp . 59-80. - - Gatsonis, C. (1989), Stability and change in childhood-onset depressive disorders: longitudinal course as a diagnostic validator. In: The Validity of Psychiatric Diagnosis, eds. L. N. Robins & J .
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E. Barrett. New York: Raven Press, pp. 57-75. - - Feinberg, T. L., Crouse-Novak, M. A., Paulauskas, S. L. & Finkelstein, R. (1984), Depressive disorders in childhood. 1. A longitudinal prospective study of characteristics and recovery. Arch.
Gen. Psychiatry, 41:229-237. - - Paulauskas, S., Gatsonis, C. & Richards, C. (1988), Depressive disorders in childhood. III. A longitudinal study of comorbidity with and risk for conduct disorders. J. Affective Disord., 15:205-217. - - Gatsonis, C., Paulauskas, S. L. & Richards, C. (1989), Depressive disorders in childhood. IV. A longitudinal study of comorbidity with and risk for anxiety disorders. Arch. Gen. Psychiatry, 46:776--782. Lefkowitz, M. M. & Tesiny, E. P. (1985), Depression in children: prevalence and correlates. J. Consult. Clin. Psychol., 53:647-656. McGee, R., Anderson, J., Williams, S. & Silva, P. A. (1986), Cognitive correlates of depressive symptoms in 11-year-old children. J.
Abnorm. Child Psychol., 14:517-524. Mullins, L. L., Siegel, L. J. & Hodges, K. (1985), Cognitive problemsolving and life event correlates of depressive symptoms in children.
J. Abnorm. Child Psychol., 13:305-314. Nolen-Hoeksema, S., Girgus, 1. S. & Seligman, M. E. P. (1986), Learned helplessness in children: a longitudinal study of depression, achievement, and explanatory style. J. Pers. Soc. Psychol., 51:435442. Puig-Antich, J. (1982), Major depression and conduct disorder in prepuberty. J. Am. Acad. Child Psychiatry, 21:118-128. - - (1987), Affective disorders in children and adolescents: diagnostic validity and psychobiology. In: Psychopharmacology. The Third Generation ofProgress, ed. H. Y. Meltzer. New York: Raven Press, pp. 843-859. - - Lukens, E., Davies, M., Goetz, D., Brennan-Quattrock , J. & Todak, G. (1985a), Psychosocial functioning in prepubertal major depressive disorders. 1. Interpersonal relationships during the depressive episode. Arch. Gen. Psychiatry, 42:500--507. - - - - - - - - - - - - (1985b), Psychosocial functioning in prepubertal major depressive disorders. II. Interpersonal rela-
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tionships after sustained recovery from affective episode. Arch. Gen. Psychiatry, 42:511-517. Rutter, M. (1986), The developmental psychopathology of depression: issues and perspectives. In: Depression in Young People. Developmental and Clinical Perspectives, eds. M. Rutter, C. E. Izard, & P. B. Read. New York: Guilford Press, pp. 3-30. Ryan, N. D., Puig-Antich, J., Ambrosini, P. et al. (1987), The clinical picture of major depression in children and adolescents. Arch. Gen. Psychiatry, 44:854-861. Sacco, W. P. & Graves, D. 1. (1984), Childhood depression, interpersonal problem-solving, and self-ratings of performance. Journal of Clinical and Child Psychology, 13: 10--15. Spitzer, R. L., Endicott, J. & Robins, E. (1978), Research diagnostic criteria. Rationale and reliability. Arch. Gen. Psychiatry, 35:773782. Strauss, C. C., Forehand, R., Frame, C. & Smith, K. (1984), Characteristics of children with extreme scores on the Children's Depression Inventory. Journal of Clinical and Child Psychology, 13:227231. Strober, M. & Carlson, G. (1982), Bipolar illness in adolescents with major depression. Clinical, genetic, and psychopharmacologic predictors in a three-to-four-year prospective follow-up investigation. Arch. Gen. Psychiatry, 39:549-555. Tesiny, E. P., Lefkowitz, M. M. & Gordon, N. H. (1980), Childhood depression, locus of control, and school achievement. Journal of Educational Psychology, 72:506--510. Wechsler, D. (1974), Manualfor the Wechsler Intelligence Scale for Children - Revised. New York: Psychological Corporation. Weinberg, W. A., Rutman, 1., Sullivan, L., Penick, E. C. & Dietz, S. G. (1973), Depression in children referred to an educational diagnostic center: diagnosis and treatment. J. Pediatr., 83:1065-
1072. Weiner, A. S. & Pfeffer, C. R. (1986), Suicidal status, depression, and intellectual functioning in preadolescent psychiatric inpatients.
Compr. Psychiatry, 27:372-380.
J. Am. Acad. Child Adolesc. Psychiatry, 30:3, May 1991
AN D
DAVID GOLDSTON , PH.D.
Abstract. Depressed j uveniles show evide nce of functional impairment in various cog nitive and social domains. Actual school performance seems to be more co nsistently affected by depression than cog nitive and intellect ual abilities . In addition, depressed youth appear to be less socially adept than nondepressed peers, although depression does not consistently impair social-cog nitive abilities . Indications that depressed youth show mild decl ines in tested verbal perform ance over time and that residual problems in social functionin g persist after symptomatic recovery suggest that major depre ssion may have negative effec ts on development in childhood. J, Am . Acad . Child Adolesc . Psychiatry, 1991 ,30, 3:388-392 . Key Words: cog nitive development, social deve lopment, depression in childhood . There is now convincing evidence that school-aged children and adolescents do suffer from depressive disorders and that these disorders disrupt young patients ' function ing in a variety of areas (Kovacs, 1989, Puig-Antich , 1987). One important question that remains is whether, and to what extent, childhood-onset affective illness has deleterious consequences on normal development (Rutter , 1986). Longitudinal study is the most suitable way to investigate these developmental issues. However, cross-sectional study can also provide pertinent information if age-specific normative data are available that enable inferences about developmental lags. The purpose of the present article is to review the research evidence on the development of depressed children and adolescents . The focus is on two domains of development that have received much attention recently , namely, cognit ive development and social-co gnitive development. Cognitive development has been commonly studied as intellectual performance, problem -solving ability, and academic achievement. Social-cognitive development has been examined in terms of actual social behavior, interpersonal problem-solving ability, and social concept formation. The concept of " development" reflects the assumption that functioning in cognitive and social-cognit ive domains progress with the age and maturity of the child , either as qualitative "leaps" or quantitative gains. In assessing these developmental domains, it is important to distinguish between abilities and skills on the one hand , and actual performance and behavior on the other hand . The presence of a psychiatric disorder Accepted November 8. 1990 . Dr. Kovacs is with the Western Psychiatric 1nstitute and Clinic. University of Pittsburgh School of Medicine. Dr. Goldston is with the Department of Psychiatry and Behavioral Medicine, Bowman Gray School of Medicine of Wake Forest University. Preparation of this paper was supported by Grant No . MH-33990 fr om the National Institute of Mental Health , Health and Human Services Administration and a grant fro m the W. T. Grant Foundation. The authors would like to dedicate this article to the memory of Joaquim Puig-Antich, M.D .• fr iend and colleague. Reprint requests to Dr . Kovacs. Western Psychiatric Institute and Clinic. 3811 O'Hara Street. Pittsburgh. PA 15213. 0890 -8567/91/3003 -0388$03 .00/0 © 1991 by the American Academy of Child and Adolescent Psychiatry .
388
may impair only perform ance but have no obvious effect on the abilities and skills that are necessary to carry out the performance , or it may disrupt the developmental progression both of abilities and accompanying behav ior. To appreciate the potenti ally negative effects of the depressive disorders in the juvenile years, their clinic al features are briefly reviewed , and how various feature s may interfere with cognitive and social functioning is discussed . The available research eviden ce regarding their effect s on children' s development is then summarized .
Clinical Features of Childhood-Onset Depressive Disorders Depressive disorders have been diagnosed even among preschoolers (e.g. , Kashan i and Carlson , 1985) accord ing to operational criteria , such as the Research Diagnost ic Criteria (Spitzer et a!. , 1978) and the DSM-ll/ . An episode of major depression in childhood lasts about 10 months on average, may have psychotic or melancholic features , and rarely occurs in a "pure" form (Kovacs and Gatsonis, 1989; Puig-Antich, 1987; Strober and Carlson, 1982). In fact , depressed youth often have multiple concurrent psychi atric problems, with anxiety disorders and conduct disorders being among the most prevalent comorbid conditions (Kovacs et ai., 1988 , 1989 ; Puig-Antich , 1982 ). Although major depression in childhood is associated with a high rate of recovery , youngsters with such a history are at a very high risk for developing a recurrent episode of major depres sion and are at increased risk for bipolar disorder (Kovacs and Gatsonis, 1989; Strober and Carlson, 1982). Children and adolescents can also manifest dysthymic disorder (or minor depression ), which is a presumably less severe although a protracted affective disturbance . Dysthymic disorder in childhood lasts over 3'12 years on average . It has many features in common with major depression, including a high rate of eventual recovery . Juvenile-onset dysthymic disorde r is also associated with a high rate of comorbid psychiatric disorders, an increased risk for major depression , and a risk for bipolar outcome (Kovacs and Gatsonis, 1989). When the syndrome of major depres sion is exam ined from a developmental perspective, school-age and adolescent patients appear to show some age-associated variations in l.Am .Acad. Chil d Adolesc . Psychiatry, 30:3, Ma y /99/
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symptomatology. Specifically, complaints of hypersomnia and anhedonia appear to be more characteristic of older children; whereas, hyposomnia, separation anxiety, and somatic complaints are more frequent among younger patients (Kovacs and Gatsonis, 1989; Ryan et al., 1987). Nonetheless, a search for developmental-stage mediators of symptom expression has not proven to be enlightening. That is, using a Piagetian perspective, children at various stages of development did not show the hypothesized differences in symptoms and disorder characteristics (Kovacs and Paulauskas, 1984). In spite of isolated age-associated variations, the prototypical picture of major depression generally appears to be similar across age groups.
Possible Effects of Depression on Cognitive and Social Functioning and Development There are a number of ways in which depressive disorders may have detrimental short-term and long-term effects on cognitive and social functioning and development. The negative effects could derive from specific depressive symptoms , the overall impact and length of the episodes, and the combination of symptom characteristics and disorder duration. Certain depressive symptoms may be particularly disruptive of cognitive functioning. For instance, prolonged difficulties with concentration, anhedonia, and psychomotor retardation could affect intellectual and academic achievement. Attentional problems that often characterize depressive illness may interfere with the process of mastering new, unfamiliar, or complex academic problems . Reduced motivation may make it difficult to engage in learning tasks that are demanding or those that require "effortful" processing (Cohen et al., 1982). Psychomotor retardation may slow the rate of acquisition and consolidation of information for long-term memory and also may cause depressed students to perform poorly on timed tests. Academic failure, in turn, is likely to undermine further youngsters' self-esteem and contribute to subsequent negative learning experiences. Some depressive symptoms may also have adverse effects on social cognition and social problem-solving skills. For instance, in the presence of social withdrawal and anhedonia, normal interactions with peers and adults are precluded . This may appear as a failure to show proper initiative and reciprocity in interpersonal situations . The irritability of depressed youths and the nonverbal manifestations of depression (e.g ., avoidance of eye contact) may be perceived by others as noxious, may discourage overtures and attention from other individuals, and thus may increase the youngsters' social isolation . Depressed youth therefore may be deprived of the social interactions that reinforce ageappropriate social skills and are necessary for the continued development of the understanding and management of interpersonal situations. A youngster suffering from major depression or dysthymia of even a l-year duration is impaired for a significant portion of his or her age span . Moreover, the dysfunction occurs during a stage of life that ordinarily is associated with the rapid acquisition of new information and the unl .Am. Acad. Child Adolesc. Psychiatry, 30:3, May 1991
folding of increasingly sophisticated problem-solving strategies. It is likely that lengthy periods of major affective disorder in childhood interfere with or delay such normal developmental progression; namely, the illness disrupts the transactions with the environment that facilitate learning, development, and the utilization of any newly acquired information (e.g. , Gordon, 1988). For instance, an l l-yearold boy who is depressed for 1 year or longer may miss out on important cognitive and social learning experiences during his period of symptomatology. Relative to his or her peers, he may consequently be developmentally delayed in the cognitive and social domains when his depression remits. The severity, persistence, and long-term consequences of such delays also could be mediated by the patients' developmental stage among other factors. For example, cognitively and socially less sophisticated younger children may be rendered more dysfunctional by their depressions . They may have more trouble "catching up" to developmental milestones than older youths who had had more extensive coping repertoires before depression onset.
Empirical Studies of Depression and Development To determine the cognitive and social-cognitive functioning of depressed juveniles, investigators have assessed abilities and skills (using intelligence tests and analogue tests of social problem solving) as well as actual school performance and social behavior. Although almost all of the information derives from cross-sectional studies, it is possible to make some inferences about the effects of depression on development when normative data are available. To start with, the overall intellectual potential of depressed juveniles is generally comparable with that of the normal population (e.g ., Kashani et al., 1983; Weinberg et al., 1973; Weiner and Pfeffer, 1986), suggesting no substantive prior delay in this domain. However, depression still appears to have some impact, although its effect on global intellectual performance may be relatively weak. This is suggested by the modest although statistically significant negative associations between severity of depression (assessed by peer nomination, self-rating, or self-report) and various measures of intelligence in studies of large, school based, or epidemiological samples (Lefkowitz and Tesiny, 1985; McGee et al. , 1986; Tesiny et al., 1980). There are also some indications that depression may selectively impair specific cognitive functions . In at least two studies of students classified as depressed and nondepressed, based on self-rated symptom scales, depression was associated with impaired performance on tasks requiring attention, coordination, and psychomotor speed but did not adversely affect verbal skills and verbal intellectual performance (Kaslow et al. , 1983; 1984). In other studies, however, depressed juveniles performed equally well on tasks of verbal and nonverbal intelligence or manifested a tendency toward a somewhat lower verbal than performance IQ (Brumback et al., 1977, 1980; Kashani et al., 1983; Weinberg et al., 1973; Weiner and Pfeffer, 1986). The data are more consistent concerning the relationship of depression to scholastic achievement and academic performance (e.g., Brumback et al., 1980; Lefkowitz and Tes389
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iny, 1985; Nolen-Hoeksema et al., 1986; Puig-Antich et al., 1985a; Strauss et al., 1984; Tesiny et al., 1980; Weinberg et al., 1973). This body of literature indicates that youngsters who report depressive symptoms, who are viewed by their peers as depressed, or whose depression is detected by psychiatric examination tend to perform poorly in school and have various academic difficulties. Additionally, increasing severity of depression among students is associated with poorer performance on standardized achievement tests, and teachers view depressed children as doing less well academically than their nondepressed peers. The social cognitive abilities thought to be necessary for appropriate social functioning appear to be relatively unaffected by depression. For example, according to several school-based studies that defined depression by self-rating scales and used analogue social problem-solving tasks, depressed youngsters were generally as capable as their nondepressed peers of providing cognitive solutions to interpersonal problems (Mullins et al., 1985). Additionally, when multiple aspects of interpersonal problem solving were examined, depressed children performed as well as nondepressed peers on the majority of tasks (Sacco and Graves, 1984). . On the other hand, symptomatic youngsters do show impaired social-interpersonal behaviors. When they are observed in actual situations, depressed children are consistently described as less socially adept than nondepressed peers; they also are preferred less often as play- or workmates (Altmann and Gotlib, 1988; Blechman et al., 1986). Compared both to nondepressed "neurotic" and normal age mates, clinically depressed children have worse peer relationships, including less peer contact and fewer, if any, best friends (Puig-Antich et al., 1985a). Studies that used peer nomination techniques in classroom settings also have consistently revealed that children who view themselves as depressed are more rejected, more isolated, less liked, and less assertive than nondepressed schoolmates (e.g., Altmann and Gotlib, 1988; Kennedy et al., 1989; Tesiny et al., 1980). In summary, the results of cross-sectional studies suggest that depression in the juvenile years is associated with deficits in cognitive and social functioning. These effects appear most consistenly with observable behaviors: namely, actual school performance and social interactions. In contrast, depression appears to be less disruptive of developmentally mediated "internal" abilities and potentials. However, these cross-sectional data do not provide information as to whether the children's school and social problems preceded their depression. Cross-sectional studies also do not shed light on whether the impairments are merely contemporaneous with the depression, if they persist over time, or if the impairments have consequences for later functioning. Longitudinal study provides the most appropriate vehicle for examining such issues in developmental psychopathology. While longitudinal study may not completely illuminate the nature of the relationship between different variables over time, it can serve to establish temporal patterns from which causal relationships may at least be inferred. Unfortunately, little information exists currently on the 390
long-term cognitive and social-cognitive development of depressed juveniles. However, there are some indications that children with major depressive illness may be at risk for continued cognitive and social problems that may persist even after symptomatic recovery. This information derives primarily from two studies: a 4-month follow-up of recovered cases by Puig-Antich and associates (l985b) and the authors' own ongoing longitudinal investigation of the nosology and course of childhood-onset depressions. In the authors' own study (which is currently in its 12th year and is described elsewhere in detail, see Kovacs et al., 1984; Kovacs and Gatsonis, 1989), 8- to 13-year-old clinically referred children, who met DSM-III criteria for depressive disorder, were assessed repeatedly with a comprehensive battery of tests and psychiatric measures. The battery included the yearly administration of a short version of the WISC-R (Vocabulary and Block Design subtests) (Wechsler, 1974); school records were also routinely obtained. Preliminary results suggest both temporary and longer term negative correlates of affective illness; the diagnosis of major depression seemed to be most consistently associated with performance deficits (Kovacs et al., 1990, submitted for publication). Children showed lower nonverbal intellectual performance during their index episode of major depression, compared with when they were no longer in the episode. In contrast, verbal performance during the episode of major depression was not impaired (compared with when not in the depressive episode), paralleling the bulk of previous findings from cross-sectional studies. For dysthymic children, no performance differences were evident as a function of being in or out of the episode of dysthymia. However, longitudinal analyses revealed mild declines in verbal intellectual performance over subsequent years among children with major depression or dysthymia, which may partly
reflect a disruption in the acquisition of verbal skills. The decline in verbal intellectual performance over time was also influenced by sociodemographic factors but could not be attributed to the presence of comorbid conduct disorders. In addition, major depressive disorder appears to have enduring effects on school performance. Puig-Antichand associates' (l985b) follow-up of depressed children, who have been in remission for at least 4 months, revealed only a trend toward improvement in school functioning. In the present author's study, it was found that children with a longer history of depression received poorer grades over time, and that the proportion of time a child had had a major depression during the school year was negatively related to grade point average (Kovacs et al., 1990, submitted for publication) . Consistent with the results of cross-sectional studies, the present authors also found that, with continued observation, the depressed patients showed progression on "Piagetian" tasks of social cognition, although their rate of development may have been somewhat delayed. In terms of actual social behavior, the follow-up of Puig-Antich and associates (1985b), however, suggests that some impairment persists in actual peer relationships even after sustained recovery from the depression. l.Am.Acad. Child Adolesc. Psychiatry, 30:3, May 1991
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Discussion In the present article, the issue as to whether depre ssive disorders in the juvenile years disrupt or interfere with cognitive and social cognitive development is addressed. These two domains of development have come to attract increased attention partly because of the salience of cognitive and social-cognitive factors in adaptation during the school-age years and also because recent theories have implicated cognitive and social factors in the etiology of depression. According to currently available data, there do not appear to be any obvious preexisting impairments in depressed children's intellectual functioning. However, cross-sectional studies provide some evidence that the presence of depressive symptoms or diagnosable depression does have a negative impact in certain cognitive and social areas. The deficits in functioning are most compelling in investigations of actual behavior. Studies of cognitive abilities or potentials using various tests have yielded less consistent findings. However, the scarcity of developmental-stage specific normative information on social cognition and functioning leaves open the possibility that some depression-associated social deficits may have preceded the disorder. Longitudinal study also revealed deficits in nonverbal cognitive and intellectual performance in association with depression, thereby supporting and extending the results of several cross-sectional projects . However, what was not evident from cross-sectional studies was that the impairments in nonverbal intellectual performance are temporary, and that , similar to "state markers ," they resolve after the depressive episodes remit. It also was not evident from cross-sectional studies that children with depressive disor ders may show increasing deficits in verbal functioning and continue to be socially impaired over time. In summary then, it appears that deficits in actual intellectual and social performance or behavior do not necessarily reflect deficits in abilities and potentials. Nonetheless, depression in childhood may have long-term negat ive effects because it may significantly disrupt and interfere with the process of continued learning and social adaptation. It would also seem that persistent disruptions in age-appropriate behaviors can lay the groundwork for subsequent developmental delays. Although further longitudinal studies are needed to obtain a more coherent picture of the developmental patterns of depressed juveniles, associated methodological problem s make it difficult to totally disentangle temporal relationships. For example, it appears logical that aspects of the depressive syndrome (e.g., attentional and motivational problems, psychomotor retardation) could precipitate contemporaneous performance deficits on nonverbal tasks. Such deficits have been clearly demonstrated in adults and have been attributed, in part, to some generalized deficit in a central motivational state (Cohen et aI. , 1982). Depression can also be expected to interfere with the process of learning and education and thereby disrupt the continuous acquisition of verbal skills over time. The temporal patterns observed with regard to the behavior of depressed children support such inferences. However, temporal precedence does not necessarily mean causality . Causal relationships can only l.Am . Acad. Child Adolesc. Psychiatry , 30:3, May 1991
be tested within experimental settings that permit the manipulation of certain variables, while important sources of variation are controlled. Such investigations are, therefore, needed to verify the temporal-causal trends that emerge from studies of the cognitive and social functioning of depressed youth. Studies also are needed to determine the effects of interventions that focus on reversing depression-associated deficits or ameliorating the functional consequences of these disorders. Such efforts could be justified by data from crosssectional studies suggesting that whereas cognitive and social behavior may be impaired during the depression, potential skills and abilities needed to execute such behaviors remain relatively intact, at least in the short run. Therefore , remediation of dysfunctional behaviors that are evident during the depression could possibly forestall subsequent developmental delays or prevent the accumulation of cognitive and social failure experiences.
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