BIOL PSYCHIATRY 1991;29:735- ?3?
735
EDITORIAL
Psychopathology and Common Sense
Where We Went Wrong With Negative Symptoms Descriptive psychiatry at the turn of the century was rich in observation, d e ~ l , and concept. When Kraepelin described avolition in dementia praecox, one could easily grasp the fundamental importance of the phenomenon and the varied manifestations that might be indicative of its presence. Understanding the construct, one would not use social wi,:drawal and avolition interchangeably since only social withdrawal emanating from low drive is indicative of avolition, while social withdrawal from other factors such as paranoid guardedness or autistic preoccupation with psychosis would be entirely different. Similarly, dissociative processes, the other major feature Kr tepelin ascribed to dementia praecox, was understood as a construct and appropriately reflected in descriptions of symp~o~ manifestations. Modern day descriptive psychiatry, unfo._~=,~.ely, lacks the conceptual or descriptive precision that characterized earlier work. Admittedly, much has been gained in drawing attention to issues of reliability and in reaching agreement on criteria for diagnosis. However, there has been a growing tendency to make the categorization of psychopathology concept-free, guided in large measure by psychometric and probabilistic considerations. One even encounters diagnostic systems for major mental illness that include criteria such as ~ender or marital status simply because their inclusion within the context of certain disease manifestations enhances the probability of assignment to a disease category. Although this approach to psychopathology is likely to delight even the most dispassionate objective psychiatrists, it contributes to major flaws in current psychopathologic appreaches to schizophrenia. Differential diagnosis, including consideration of probable causation, is fundamental to a scientific classification of disease manifestations. While the differential aspect of the diagnostic process is accepted in theory, surprising exceptions occur in practice. If, for example, one encounters a patient with limited facial expression of emotion in a diagnostic .... h.o,;.., a ;,,a.m~.t must h~ made a~ to whether or not this is vathologic, tf it is considered pathologic, it may be attributable to any one of several diagnoses, including schizoid personality disorder, an affective disorder, Parkinson's disease, and schizophrenia. However, if a diagnosis of schizophrenia has already been established, the importance of restricted facial expression for further differential diagnostic purposes will depend on whether or not it is intrinsic to the disease. There are many causes of restricted affect in patients with schizophrenia, including neuroleptic effect (e.g., akinesia, sedation); adaptive response to, or preoccupation with, psychosis; demoralization or depression; and, at times, chronic exposure to nonstimulating social environments. The schizophrenia expert is usually interested in restricted emotional expression if it is a primary manifestation of the disease process per se; if there ~ e other sources of this symptom it complicates the study of schizophrenia. Journals are now replete with reports concerned with negative symptoms in schizophrenia. This has proven to be an influential heuristic. It is evident in the majority of ~,
¥ (~lJLil.af.ll,l~ai,
© 1991 Society of Biological Psychiatry
v ~
. . - ~
.
.
.
.
.
x
0006-3223/91/$03.50
736
BIOL PSYCHIATRY
Editorial
1991 ;29:735-737
these reports that the negative symptom hypotheses are concerned with core pathology of schizophrenia rather than other sources of negative symptoms. Although findings often suggest associations between negative symptoms and the various dependent or validating measures in study designs, these associations are often weak within study and inconsistent across studies. This is not surprising. If there can be multiple sources for negative symptoms then only one of these should determine an ass~ia~on with dependent measures, otherwise the relationships found are invariably weakened. Since other sources of negative symptoms are common in patients with schizophrenia, error attributable to compromised negative symptom ascertainn~nt will be extensive. The most widely used assessments for negative symptoms are the Brief Psychiatric Rating Scale (BPRS) and the Scale for the Assessment of Negative Symptoms (SANS). In spite of the fact that negative symptoms in schizophrenia originate from multiple sources, these approaches require that observed phenomena be rated without consideration of causality. Mayer et al (1985) have reported on the obfuscating effects of such an approach when finding multiple sources contributing to restricted affect within a schizophrenia cohort. It is rare that hypotheses are concerned with other than primary negative symptoms, the identification of which requires consideration of causality. Have the studies of the association of brain structures to negative symptoms been interested in anything other than those negative symptoms intrinsic to the pathophysio!!ogy of the illness? I think not. If we assert that a drug effectively treats negative symptoms in schizophrenia patients, we surely do not simply mean that secondary negative symptoms are reduced. Yet we uncritically accept assessment methodologies which make no provision for addressing the differential classification of such symptoms. An etiologic approach to diagnosing negative symptoms is straightforward in clinical care, an~ ~'reatment is compromised if differential diagnosis is not based on causal presumptior~ (Carpenter et al 1985). lavestigators risk criticism in peer review if they do no, t'se commonly accepted assessment procedures, and too frequently we select "standard" procedures without regard to the specific demands of our experiment. That this is a blind spot is indicated by the rarity of reports or reviews or, negative symptoms that discuss assessment limitations in study design. When challenged, investigators sometimes state that they cannot focus on primary negative symptoms since vah.~ and reliable ascertainment has not been established. If this is the basis for failing to use appropriate methods, they only need to be made aware that considerable evidence already exists that primary negative symptoms can be reliably judged and have been shown to be valid. Restricted affect iz a putative negative symptom, and poor rapport captures diminished capacity for social cognition. These measures, reliably rated in the Present State Examination (WHO 1974), proved to be decisive attributes in th,e differential diagnosis among psychotic cases (Carpenter et al 1973). A comprehensive outcome assessment scale containing seven reliable negative symptoms defined as primary to the schizophrenia process (Heinrichs et al 1984), was found to be reliable by other investigators (Meltzer et al 1990; Beliack et al 1990); so, too, with irreversible negative symptoms (Krawiecka et al 1977) in the Crow Type II schizophrenia distinction (Crow 1985) and with the Posifi,~.e aria ~T,.g.~,;,,o~,,,,a . . . . ~_,~.~"al*(Itr.ay . t ~! I O~'/~,, ---'--~~lth"~!!°h th.a l ~ p r .~.ie . . . . . ~, . . . . in differentiating primary from secondary. Six negative symptoms used to differentiate between schizoplu'enia with the deficit syndrome and schizophrenia without the deficit syndrome are reliable as items, and for categorical distinction (Kirkpatrick et al 1989). Validity of this diagnostic distinction is supported by evidence drawn from premorbid development data, psychosis proneness determinations, neuropsyehological test findings,
Editorial
mot. wVCmATRY
737
1991 ;29:735--737
oculomotor assessments, and metabolic PET imaging patterns (Carpenter et al 1991, in press). The time has come to carefully relate assessment and classification procedures in schizophrenia research to the key dimensions of psychopathology, particularly deficit symptoms. Investigators should be encouraged to select approaches that meet more rigorous study requirements and resist the considerable pressure to conform to accepted measurement procedures when these are conceptually flawed for the specific q u e s t i ~ under study. Peer reviewers for research grants and journal publications can help by emphasizing relevance, meaningfulness, and validity rather than adherence to common practice. In the meantime, clinicians should be aware that the presumed psychopathologic constructs (e.g., negative symptoms define the avolitiona~ syndrome of ICraepdin) may well mislead them in reading the research literature. Each article must be ~ t i c ~ y examined to determine the actual relationship between symptom assessment and psychopatholo~c construct. Only then can the meaning of reported data be appreciated. William T. Carpenter, Jr. Maryland Psychiatric Research Center P.O. Box 21247 Baltimore, MD 21228
References Bellack AS, Morrison RL, Wixted Jr, Mueser KT (1990): An analysis of social competence in schizophrenia. Br J P~chi~,~" 156:°09-818. Carpenter WT, Buchanan RW, Kirkpatrick B, Thaker G, Tamminga C (1991): Negative symptoms: a critique of current approaches. Proceedings of the Workshop on Negative/Posi~e Schizophrenia, June 29-30, 1990. Bonn, Germany: Springer-Verlag (in press). Carpenter WT, Heinrichs DW, Alphs LD (1985): Treatment of negative syrnptoms. Schizophr Bull 11:440-452. Carpenter WT, Strauss JS, Bartko JJ (1973!" ~ flexible system for the identificationof schizophrenia: a report from me International Pilot Study of Schizophrenia. Science 182:1275-1278. Crow TJ (1985): The two-syndrome concept: origins and current status. Schizophr Bull 11:471486. Heim'ichs DW, Hanlon TE, Carpenter WT (1984): The Quali_ryof Life Scale: an instrament for rating the schizophrenic deficit syndrome. Schizophr Bull 10:388-398. Kay SR, Opler LA, Fishbein A (i987): Positive and Negative Syndrome Scale (PANNS) Rating Manual: Social and Behavioral Sciences Documents, San Rafael. Kirkpatrick B, Buchanan RW, McKenney PD, Alphs LD, Carpenter WT (1989): The schedule for the deficit syndrome: an instrument for research in schizophrenia. Psychiat Res 30:I 19-123. Krawiecka M, Goldberg D, Vaugim M (1977): A standardized psychia~c assessment scale for rating chronic psychotic patients. Acta Psychiatr Scand 55:299-308. Mayer M, Alpert M, Stastny P, Perlick D, Empfield M (1985): Multiple contributions to clinical presentation of flat affect in schizophrenia. Schizophr Bull ! 1:420--426. Meltzer HY, Burnett S, Bastani B, Ramirez, LF (1990): Effects of six months of clozapine treatment on the quality of life of chronic schizophrenic patients. Hosp & Comm Psychiatry 41:892-897. World Health Organization (1974): Report qf the International Pilot Study of Schizophrenia, Vol. 1. WHO Press, Geneva, Switzerland.
735
EDITORIAL
Psychopathology and Common Sense
Where We Went Wrong With Negative Symptoms Descriptive psychiatry at the turn of the century was rich in observation, d e ~ l , and concept. When Kraepelin described avolition in dementia praecox, one could easily grasp the fundamental importance of the phenomenon and the varied manifestations that might be indicative of its presence. Understanding the construct, one would not use social wi,:drawal and avolition interchangeably since only social withdrawal emanating from low drive is indicative of avolition, while social withdrawal from other factors such as paranoid guardedness or autistic preoccupation with psychosis would be entirely different. Similarly, dissociative processes, the other major feature Kr tepelin ascribed to dementia praecox, was understood as a construct and appropriately reflected in descriptions of symp~o~ manifestations. Modern day descriptive psychiatry, unfo._~=,~.ely, lacks the conceptual or descriptive precision that characterized earlier work. Admittedly, much has been gained in drawing attention to issues of reliability and in reaching agreement on criteria for diagnosis. However, there has been a growing tendency to make the categorization of psychopathology concept-free, guided in large measure by psychometric and probabilistic considerations. One even encounters diagnostic systems for major mental illness that include criteria such as ~ender or marital status simply because their inclusion within the context of certain disease manifestations enhances the probability of assignment to a disease category. Although this approach to psychopathology is likely to delight even the most dispassionate objective psychiatrists, it contributes to major flaws in current psychopathologic appreaches to schizophrenia. Differential diagnosis, including consideration of probable causation, is fundamental to a scientific classification of disease manifestations. While the differential aspect of the diagnostic process is accepted in theory, surprising exceptions occur in practice. If, for example, one encounters a patient with limited facial expression of emotion in a diagnostic .... h.o,;.., a ;,,a.m~.t must h~ made a~ to whether or not this is vathologic, tf it is considered pathologic, it may be attributable to any one of several diagnoses, including schizoid personality disorder, an affective disorder, Parkinson's disease, and schizophrenia. However, if a diagnosis of schizophrenia has already been established, the importance of restricted facial expression for further differential diagnostic purposes will depend on whether or not it is intrinsic to the disease. There are many causes of restricted affect in patients with schizophrenia, including neuroleptic effect (e.g., akinesia, sedation); adaptive response to, or preoccupation with, psychosis; demoralization or depression; and, at times, chronic exposure to nonstimulating social environments. The schizophrenia expert is usually interested in restricted emotional expression if it is a primary manifestation of the disease process per se; if there ~ e other sources of this symptom it complicates the study of schizophrenia. Journals are now replete with reports concerned with negative symptoms in schizophrenia. This has proven to be an influential heuristic. It is evident in the majority of ~,
¥ (~lJLil.af.ll,l~ai,
© 1991 Society of Biological Psychiatry
v ~
. . - ~
.
.
.
.
.
x
0006-3223/91/$03.50
736
BIOL PSYCHIATRY
Editorial
1991 ;29:735-737
these reports that the negative symptom hypotheses are concerned with core pathology of schizophrenia rather than other sources of negative symptoms. Although findings often suggest associations between negative symptoms and the various dependent or validating measures in study designs, these associations are often weak within study and inconsistent across studies. This is not surprising. If there can be multiple sources for negative symptoms then only one of these should determine an ass~ia~on with dependent measures, otherwise the relationships found are invariably weakened. Since other sources of negative symptoms are common in patients with schizophrenia, error attributable to compromised negative symptom ascertainn~nt will be extensive. The most widely used assessments for negative symptoms are the Brief Psychiatric Rating Scale (BPRS) and the Scale for the Assessment of Negative Symptoms (SANS). In spite of the fact that negative symptoms in schizophrenia originate from multiple sources, these approaches require that observed phenomena be rated without consideration of causality. Mayer et al (1985) have reported on the obfuscating effects of such an approach when finding multiple sources contributing to restricted affect within a schizophrenia cohort. It is rare that hypotheses are concerned with other than primary negative symptoms, the identification of which requires consideration of causality. Have the studies of the association of brain structures to negative symptoms been interested in anything other than those negative symptoms intrinsic to the pathophysio!!ogy of the illness? I think not. If we assert that a drug effectively treats negative symptoms in schizophrenia patients, we surely do not simply mean that secondary negative symptoms are reduced. Yet we uncritically accept assessment methodologies which make no provision for addressing the differential classification of such symptoms. An etiologic approach to diagnosing negative symptoms is straightforward in clinical care, an~ ~'reatment is compromised if differential diagnosis is not based on causal presumptior~ (Carpenter et al 1985). lavestigators risk criticism in peer review if they do no, t'se commonly accepted assessment procedures, and too frequently we select "standard" procedures without regard to the specific demands of our experiment. That this is a blind spot is indicated by the rarity of reports or reviews or, negative symptoms that discuss assessment limitations in study design. When challenged, investigators sometimes state that they cannot focus on primary negative symptoms since vah.~ and reliable ascertainment has not been established. If this is the basis for failing to use appropriate methods, they only need to be made aware that considerable evidence already exists that primary negative symptoms can be reliably judged and have been shown to be valid. Restricted affect iz a putative negative symptom, and poor rapport captures diminished capacity for social cognition. These measures, reliably rated in the Present State Examination (WHO 1974), proved to be decisive attributes in th,e differential diagnosis among psychotic cases (Carpenter et al 1973). A comprehensive outcome assessment scale containing seven reliable negative symptoms defined as primary to the schizophrenia process (Heinrichs et al 1984), was found to be reliable by other investigators (Meltzer et al 1990; Beliack et al 1990); so, too, with irreversible negative symptoms (Krawiecka et al 1977) in the Crow Type II schizophrenia distinction (Crow 1985) and with the Posifi,~.e aria ~T,.g.~,;,,o~,,,,a . . . . ~_,~.~"al*(Itr.ay . t ~! I O~'/~,, ---'--~~lth"~!!°h th.a l ~ p r .~.ie . . . . . ~, . . . . in differentiating primary from secondary. Six negative symptoms used to differentiate between schizoplu'enia with the deficit syndrome and schizophrenia without the deficit syndrome are reliable as items, and for categorical distinction (Kirkpatrick et al 1989). Validity of this diagnostic distinction is supported by evidence drawn from premorbid development data, psychosis proneness determinations, neuropsyehological test findings,
Editorial
mot. wVCmATRY
737
1991 ;29:735--737
oculomotor assessments, and metabolic PET imaging patterns (Carpenter et al 1991, in press). The time has come to carefully relate assessment and classification procedures in schizophrenia research to the key dimensions of psychopathology, particularly deficit symptoms. Investigators should be encouraged to select approaches that meet more rigorous study requirements and resist the considerable pressure to conform to accepted measurement procedures when these are conceptually flawed for the specific q u e s t i ~ under study. Peer reviewers for research grants and journal publications can help by emphasizing relevance, meaningfulness, and validity rather than adherence to common practice. In the meantime, clinicians should be aware that the presumed psychopathologic constructs (e.g., negative symptoms define the avolitiona~ syndrome of ICraepdin) may well mislead them in reading the research literature. Each article must be ~ t i c ~ y examined to determine the actual relationship between symptom assessment and psychopatholo~c construct. Only then can the meaning of reported data be appreciated. William T. Carpenter, Jr. Maryland Psychiatric Research Center P.O. Box 21247 Baltimore, MD 21228
References Bellack AS, Morrison RL, Wixted Jr, Mueser KT (1990): An analysis of social competence in schizophrenia. Br J P~chi~,~" 156:°09-818. Carpenter WT, Buchanan RW, Kirkpatrick B, Thaker G, Tamminga C (1991): Negative symptoms: a critique of current approaches. Proceedings of the Workshop on Negative/Posi~e Schizophrenia, June 29-30, 1990. Bonn, Germany: Springer-Verlag (in press). Carpenter WT, Heinrichs DW, Alphs LD (1985): Treatment of negative syrnptoms. Schizophr Bull 11:440-452. Carpenter WT, Strauss JS, Bartko JJ (1973!" ~ flexible system for the identificationof schizophrenia: a report from me International Pilot Study of Schizophrenia. Science 182:1275-1278. Crow TJ (1985): The two-syndrome concept: origins and current status. Schizophr Bull 11:471486. Heim'ichs DW, Hanlon TE, Carpenter WT (1984): The Quali_ryof Life Scale: an instrament for rating the schizophrenic deficit syndrome. Schizophr Bull 10:388-398. Kay SR, Opler LA, Fishbein A (i987): Positive and Negative Syndrome Scale (PANNS) Rating Manual: Social and Behavioral Sciences Documents, San Rafael. Kirkpatrick B, Buchanan RW, McKenney PD, Alphs LD, Carpenter WT (1989): The schedule for the deficit syndrome: an instrument for research in schizophrenia. Psychiat Res 30:I 19-123. Krawiecka M, Goldberg D, Vaugim M (1977): A standardized psychia~c assessment scale for rating chronic psychotic patients. Acta Psychiatr Scand 55:299-308. Mayer M, Alpert M, Stastny P, Perlick D, Empfield M (1985): Multiple contributions to clinical presentation of flat affect in schizophrenia. Schizophr Bull ! 1:420--426. Meltzer HY, Burnett S, Bastani B, Ramirez, LF (1990): Effects of six months of clozapine treatment on the quality of life of chronic schizophrenic patients. Hosp & Comm Psychiatry 41:892-897. World Health Organization (1974): Report qf the International Pilot Study of Schizophrenia, Vol. 1. WHO Press, Geneva, Switzerland.
