583356

research-article2015

JADXXX10.1177/1087054715583356Journal of Attention DisordersDrechsler et al.

Article

The Relations Between Temperament, Character, and Executive Functions in Children With ADHD and Clinical Controls

Journal of Attention Disorders 1­–12 © 2015 SAGE Publications Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1087054715583356 jad.sagepub.com

Renate Drechsler1, Marina Zulauf Logoz1, Susanne Walitza1, and Hans-Christoph Steinhausen1,2,3

Abstract Objective: The purpose of this study was to investigate the overlap between executive functions and temperament as measured by two questionnaires and to examine characteristic profiles in children with ADHD and clinical controls. Method: Parents of 111 clinically referred children, half of whom were diagnosed with ADHD and half with other or no diagnoses, completed the Behavior Rating Inventory of Executive Function (BRIEF) and the Cloninger Junior Temperament and Character Inventory (JTCI). Results: Factor analysis of both instruments resulted in three common factors representing aspects of (1) cognitive regulation, (2) behavioral regulation, and (3) anxious/rigid tendencies. Factor (4) represented strengths and positive resources and loaded on JTCI scales only. Both instruments discriminated significantly between ADHD and non-ADHD children. Conduct disorder/oppositional defiant disorder (CD/ODD) but not ADHD accounted for problems in BRIEF Emotional Control and Self-Monitor and JTCI low Cooperativeness. Conclusion: The two instruments only partially overlap and may complement each other. (J. of Att. Dis. XXXX; XX(X) XX-XX) Keywords ADHD, temperament, executive function, ADHD, BRIEF, Cloninger’s Temperament and Character Inventory Behavioral symptoms of ADHD have been linked to personality traits and temperament (e.g., Martel & Nigg, 2006; Nigg, 2006; Nigg, Goldsmith, & Sachek, 2004) as well as to problems in executive functioning (e.g., Barkley, 1997, 2000; Willcutt, Doyle, Nigg, Faraone, & Pennington, 2005). Both concepts, namely the construct of temperament from developmental and personality psychology, and the neuropsychological construct of executive functions (EFs), are considered to be neurobiologically based and are related to the manner in which the individual reacts to stimulation and regulates internal states and behavior according to external demands. Accordingly, they may constitute key features in understanding the psychopathology of ADHD. Several studies on temperament in ADHD are based on Cloninger’s psychobiological model of personality (for a review, see Gomez & Corr, 2014). Cloninger regarded temperament as a set of biologically determined and heritable dispositions, in contrast to character traits, which were originally assumed to develop in interaction with the environment by learning (Cloninger, Svrakic, & Przybeck, 1993). Later studies revealed, however, that the heritability of character traits was as large as that for temperament (Cloninger, 2008). Consequently, it

has been questioned to what extent temperament and character might differ in nature and whether a seven-factor model might be more appropriate than a four-plus-three model (Farmer & Goldberg, 2008). While the four temperament dimensions are roughly bipolar and describe an individual’s emotional style, the three more unipolar character dimensions are related to rational rather than emotional processes and to the individual’s personal goals and values (Cloninger, 2008). In adults, low Self-Directedness and low Cooperativeness are most typically associated with psychopathology (Cloninger, 2008). According to the Cloninger concept, temperament comprises four empirically derived factors, namely Novelty Seeking, Harm Avoidance, Reward Dependence, and Persistence. Novelty Seeking includes the subscales of 1

University of Zurich, Switzerland University of Basel, Switzerland 3 Aalborg University Hospital, Denmark 2

Corresponding Author: Renate Drechsler, Department of Child and Adolescent Psychiatry, University of Zurich, Eisengasse 16, CH-8008 Zurich, Switzerland. Email: [email protected]

2 Exploratory Excitability, Impulsiveness, Extravagance, and Disorderliness. In many aspects, Novelty Seeking is equivalent to Zuckerman’s concept of sensation seeking (Zuckerman & Cloninger, 1996). Increased Harm Avoidance is characterized by worries about the future, anxiousness, shyness, and fatigability; high Reward Dependence is associated with sensitivity, emotional openness, attachment, and dependence on approval; and high Persistence refers to perfectionism, persisting on tasks, enthusiasm for one’s work, and ambition (see Goth & Schmeck, 2009). The concept of character comprises the dimensions of Self-Directedness, Cooperativeness, and Self-Transcendence. Self-Directedness is associated with goal-directedness, fluency of ideas, sense of responsibility, self-congruence, and self-acceptance; Cooperativeness is associated with social acceptance, empathy, helpfulness, compassion for others, and conscience; Self-Transcendence refers to spirituality and fantasy. Various studies have investigated the dimensions of temperament in ADHD using the Junior Temperament and Character Inventory (JTCI), which is based on Cloninger’s model. In a Korean sample, children with ADHD showed higher scores on Novelty Seeking and lower scores on SelfDirectedness and Cooperativeness compared with controls (Yoo et al., 2006). Children with ADHD symptoms had high scores on Novelty Seeking, and low scores on Persistence and Self-Directedness (Cho, Kim, et al., 2009). In another study (Purper-Ouakil et al., 2010), boys with ADHD had high scores on Novelty Seeking and low scores on Reward Dependence and Persistence, as well as low scores on the character dimensions Self-Directedness and Cooperativeness (see also Kerekes et al., 2013). Short-term remission was predicted by low Self-Directedness and high Persistence, which was interpreted as an immaturity profile. In adults with ADHD, high Novelty Seeking and low SelfDirectedness (Anckarsäter et al., 2006) and abnormalities on all temperament and character scales except for Reward Dependence and Self-Transcendence (Faraone, Kunwar, Adamson, & Biederman, 2009) have been described. Compared with other temperament and character variables, high Novelty Seeking best predicts lifetime diagnosis of ADHD (Lynn et al., 2005). Furthermore, several studies have shown that temperament profiles may differentiate between various psychopathological conditions. Both children with autism spectrum disorders and children with ADHD showed abnormal profiles compared with the normative sample, with larger impairments in the autism spectrum group and, in particular, low scores for Persistence and Self-Directedness in the ADHD group (Poustka et al., 2011). Associations between attention problems and low Persistence, between externalizing symptoms and high Novelty Seeking, and between internalizing problems and high Harm Avoidance were found in mixed clinical and non-clinical groups of children (Rettew, Copeland, Stanger, & Hudziak, 2004). These findings are in line with earlier studies, which linked sensation seeking to

Journal of Attention Disorders  conduct problems (Russo et al., 1993). Another study (Kim et al., 2010) compared parent ratings of children with oppositional defiant disorder (ODD) only, ADHD and comorbid ODD, and normal controls on the JTCI. Compared with normal controls, children with ODD scored significantly higher on Novelty Seeking and lower on Self-Directedness and Cooperativeness. The comorbid group (ADHD and ODD) showed lower Persistence and lower Self-Directedness than the ODD-only group, indicating that the comorbid condition of ODD and ADHD increases problematic psychiatric tendencies. In a sample of adults with ADHD, high Novelty Seeking scores predicted ADHD symptoms of hyperactivity/ impulsivity, whereas low Self-Directedness and increased Harm Avoidance predicted symptoms of inattention, and low Cooperativeness was related to ODD (Salgado et al., 2009). Although Cloninger’s psychobiological model links temperament dimensions to different underlying neurotransmitter systems, it does not directly relate to neuropsychological functioning. In contrast, the temperament model by Rothbart and colleagues refers to executive control tendencies (Rothbart & Bates, 1998; Rothbart, Ellis, & Posner, 2004), which overlap with Posner’s neuropsychological concept of executive attention (Posner & Raichle, 1996). According to the model by Rothbart and colleagues, temperament in young children may be divided into three empirically derived components: The first factor is called Surgency or Extraversion, which loads positively on sensation seeking (i.e., high-intensity pleasure), impulsivity, high activity level and positive emotionality, and loads negatively on shyness. The second factor, Negative Affectivity, stands for discomfort, fear, anger/frustration, and shyness. The third factor, Effortful Control, comprises inhibitory control, attentional focusing, low-intensity pleasure, and perceptual sensitivity. According to this concept, effortful control will develop to modulate the other, more reactive temperamental dispositions (Rothbart & Rueda, 2005). In their seminal works on child psychopathology and temperament, Nigg, Martel, and colleagues claim that temperament comprises regulatory processes, which may be effortful as well as reactive (Martel, 2013; Martel, GothOwens, Martinez-Torteya, & Nigg, 2010; Martel & Nigg, 2006; Martel, Nigg, & Lucas, 2008; Martel, Nigg, & von Eye, 2009; Martel, Pierce, et al., 2009; Nigg, 2006; Nigg et al., 2004). In their view, ADHD may arise from different temperamental pathways. One pathway involves low effortful control, which may lead to inattention symptoms and secondary low emotional control. Another pathway involves strong approach tendencies, with these children predominantly showing symptoms of hyperactivity/impulsivity. Children with conduct disorder/psychopathic traits, in contrast, would be characterized by very low fear, or by excessive approach tendencies in combination with frustrative aggression, or by extremely low effortful control associated with low fear or high anger.

Drechsler et al. Empirical tests of hypotheses predicting an association between top-down (effortful) response tendencies and inattentive ADHD symptoms, and between bottom-up (reactive) response tendencies and ADHD hyperactivity/ impulsivity symptoms, have yielded inconclusive results (Martel et al., 2008). However, recent empirical studies have shown that ADHD Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association [APA], 1994) subtypes could be classified into four different temperament groups: an introverted group with ADHD inattentive subtype children; a low control group with ADHD combined subtype and high comorbidity with disruptive behavior disorders; an extraverted group with ADHD combined subtype without major comorbidities; and a small group of perfectionists with obsessive traits (Martel et al., 2010; Martel, Roberts, Gremillion, von Eye, & Nigg, 2011). In a recent study on neurobiologically valid subtyping of ADHD, temperament dimensions have been linked to resting state connectivity and physiological markers, showing that a “biologically informed temperamentbased typology” might provide a better description of ADHD subtypes or presentations than current nosological criteria (Karalunas et al., 2014), which are based on etiologically non-specific behavioral symptoms. Only a small number of studies have directly investigated the relationship between EF and temperament in ADHD (e.g., Blaskey, Harris, & Nigg, 2008; Graziano, McNamara, Geffken, & Reid, 2013; Martel, 2013). One such study (Martel et al., 2008) showed that EF task performance (response inhibition, response time variability, in adolescents also set-shifting) was related to effortful control as rated by parents, but not to reactive control. Besides laboratory testing, EF may also be assessed using rating scales based on reports of EF problems occurring in everyday behavior, such as the Behavior Rating Inventory of Executive Function (BRIEF; Gioia, Isquith, Guy, & Kenworthy, 2000). This inventory comprises eight scales which are regrouped into two main indices: the Behavioral Regulation Index (BRI; including the scales Inhibit, Shift, Emotional Control) and the Metacognition Index (MI; including the scales Initiate, Working Memory, Plan/ Organize, Organization of Materials, Monitor). Subsequent analyses have shown, however, that a threedimensional construct, with Emotional Control as a third main index and a subdivision of the Monitor scale into SelfMonitor and Task Monitor subscales, provided a more appropriate model (Gioia, Isquith, Retzlaff, & Espy, 2002). Thus, the Task Monitor and Self-Monitor subscales were additionally included in the German adaptation of the BRIEF (Drechsler & Steinhausen, 2013). Parent ratings on the BRIEF have been shown to reliably discriminate between children with ADHD and non-ADHD groups (Drechsler, Rizzo, & Steinhausen, 2008; Drechsler & Steinhausen, 2013; Linder, Kroyzer, Maeir, Wertman-Elad, & Pollak, 2010; Mahone et al., 2002; McCandless &

3 O’Laughlin, 2007; Shimoni, Engel-Yeger, & Tirosh, 2012). In a Chinese sample of children (Qian et al., 2010), BRIEF also differentiated between ADHD only and ADHD with comorbid ODD, with the latter group being rated by parents as more impaired. Interestingly, several studies have shown that the association between EF as rated on the BRIEF by parents and teachers and EF as assessed by objective neuropsychological tests is low (Drechsler & Steinhausen, 2013; Silver, 2014), although BRIEF ratings seem to be better predictors of ADHD status than EF tests (Toplak, Bucciarelli, Jain, & Tannock, 2009). It has been concluded that the BRIEF scale, while being a very useful tool for the assessment of “a broad range of concerns” in children with behavioral difficulties and at risk of developing social or school-related problems (McAuley, Chen, Goos, Schachar, & Crosbie, 2010), seems to assess another construct than EF performance measures (Bodnar, Prahme, Cutting, Denckla, & Mahone, 2007; McAuley et al., 2010). To date, it remains unclear how this construct should be defined, and to which concepts other than EF it might be related. One may, therefore, ask to what extent the construct underlying the BRIEF scale may overlap with or diverge from measures of temperament and character. In the current study, we pursued three objectives: First, we analyzed potential overlaps between EFs and Cloninger’s classic temperament dimensions in a mixed clinical sample of children and adolescents, almost half of whom had been diagnosed with ADHD. We hypothesized that cognitive EF aspects, as summarized in the BRIEF MI, should be related to the “effortful control” temperament dimension of low Persistence, whereas behavioral and emotional aspects of EF, as assessed by the BRIEF BRI scales including the subscale “Self-Monitor,” should be associated with high Novelty Seeking. To the best of our knowledge, the relation between BRIEF EF components and JTCI (or Temperament and Character Inventory [TCI]) temperament dimensions has not been previously investigated (for overlaps between BRIEF adult scales and temperament scales according to Rotbarth’s concept, see Bridgett, Oddi, Laake, Murdock, & Bachmann, 2013). Therefore, we also intended to explore these two expected associations as well as other possible associations between BRIEF and JTCI by means of factor analysis. The second objective was to analyze whether BRIEF and JTCI both discriminate between children with ADHD and clinically referred children with other or no diagnoses, and to examine in which way the two scales may differentially contribute to the description of ADHD. As only a minority of studies on temperament and on EFs in ADHD controlled for comorbid conduct disorder/oppositional defiant disorder (CD/ODD; Blaskey et al., 2008; Martel, 2013; Martel et al., 2011), none of which were based on the Cloninger model, third, we also studied the impact of these comorbidities on parent ratings of both instruments.

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Journal of Attention Disorders 

Table 1.  Description of the Sample. ADHD (n = 52) Age in years, M (SD) Gender CBCL (T scores, M, SD)  Withdrawn  Anxious/depressed   Somatic complaints   Social problems   Thought problems   Attention problems   Delinquent behavior   Aggressive behavior  Internalizing  Externalizing Clinical diagnoses (n)   Hyperkinetic disorders (F90.x) (including hyperkinetic conduct disorder [F90.1] n = 10)   Conduct disorder (F91.X)   Mixed disorder of conduct and emotion (F92.X)   Pervasive developmental disorders (F84.X)   Emotional disorders (F93.X)   Reaction to stress and adjustment disorders (F43.X)   Tic disorder (F85.X)   Obsessive-compulsive disorder (F42.X)   Disorders of social functioning (F94.X)   Anxiety disorders (F41.X, F42.X)   No clinical diagnosis

Clinical non-ADHD (n = 59)

p

8.81 (1.25) 11 girls

8.78 (1.24) 17 girls

n.s. n.s.

60.0 (10.3) 61.0 (11.3) 57.6 (9.7) 61.4 (7.3) 58.5 (8.3) 66.8 (7.4) 60.5 (8.4) 64.1 (9.5) 59.6 (11.4) 63.4 (9.7)

58.2 (7.5) 60.8 (10.1) 60.3 (9.2) 59.2 (7.0) 57.8 (9.4) 59.4 (7.5) 57.0 (7.4) 60.2 (9.1) 59.6 (10.4) 57.2 (12.0)

n.s. n.s. n.s. n.s. n.s. .5) between JTCI Novelty Seeking and BRIEF BRI scales Inhibit, Emotional Control, and Self-Monitor; (b) moderate (r ≥ .49) between JTCI Persistence and all BRIEF MI scales, including Task Monitor; and (c) low (r < .4) between the two remaining JTCI temperament scales Harm Avoidance and Reward Dependence and both BRIEF Indices, except for the moderate association between JTCI Harm Avoidance and BRIEF Shift (r = .437). Overall, the strongest associations were found between high JTCI Persistence and the BRIEF subscale Task Monitor (r = −.64), and between JTCI Novelty Seeking and BRIEF Inhibit (r = .62). The Self-Directedness scale of the JTCI correlated negatively with all BRIEF scales, showing the highest, albeit only moderate, correlations with BRIEF Emotional Control, Initiate, and Self-Monitor. Cooperativeness was inversely correlated with all BRIEF scales, and also showed the highest correlations with Inhibit, Emotional Control, and Self-Monitor. Correlations between JTCI Self-Transcendence and BRIEF scales were not significant. The BRIEF BRI was correlated more strongly than the BRIEF MI with JTCI Novelty Seeking (z = 2.93, p < .002), and the BRIEF MI more strongly than the BRIEF BRI with JTCI Persistence (z = 4.126; p < .000). Exploratory factor analysis of nine BRIEF scales (including the two Monitor subscales) and seven JTCI scales resulted in four factors as shown in Table 3. Factor 1, indicating cognitive regulation problems, loaded highly (above .9) on BRIEF Working Memory, and moderately to highly on BRIEF Initiate, Plan/Organize, Organization of Materials, Task Monitor and inversely on JTCI Persistence. Factor 2, which stands for behavioral and emotional regulation problems, loaded highly on all BRIEF Behavioral Regulation Index scales, including Self-Monitor, as well as on JTCI Novelty Seeking, and loaded negatively on Cooperativeness. Factor 3, indicating anxious and rigid tendencies, loaded on JTCI Harm Avoidance and on BRIEF Shift as well as negatively on JTCI Reward Dependence and Self-Directedness, and moderately on the BRIEF Initiate and Emotional Control scales. Finally, Factor 4 loaded on JTCI scales only and was indicative of strengths and positive resources. The MANOVA of BRIEF scales comparing children with ADHD and children with other/no diagnoses resulted in a significant group effect, Wilks’s λ = .695, F(9, 101) = 4.924, p < .000, η2p = .305, with significant group differences on seven scales (Table 4). Six of these differences

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Journal of Attention Disorders 

Table 2.  Correlations Between BRIEF and JTCI Scales (N = 111). JTCI Temperament

  BRIEF Behavior Regulation Index  Inhibit  Shift   Emotional Control   Self-Monitor BRI total Metacognition Index  Initiate   Working Memory  Plan/Organize   Organization of Materials  Monitor   Task Monitor MI total

Reward Dependence

Character

Novelty Seeking

Harm Avoidance

SelfSelfPersistence Directedness Cooperativeness Transcendence

.616*** .383*** .526*** .556*** .591***

−.061 .434*** .272** .017 .214*

−.195* −.303** −.216* −.267** −.220*

−.366*** −.148 −.262** −.364*** −.231*

−.330*** −.473*** −.436*** −.396*** −.438***

−.550*** −.512*** −.545*** −.542*** −.566***

−.093 −.028 .016 −.139 .054

.276** .329*** .372*** .417*** .583*** .443*** .389***

.222* .012 .097 .006 −.092 −.189* .055

−.369*** −.172 −.204* −.154 −.269** −.185 −.268**

−.494*** −.554*** −.509*** −.495*** −.571*** −.638*** −.565***

−.574*** −.401*** −.404*** −.342*** −.386*** −.266** −468***

−.420*** −.278** −.334*** −.427*** −.555*** −.406*** −.439***

−.194* −.079 −.072 −.098 −.172 −.158 −.071

Note. BRIEF = Behavior Rating Inventory of Executive Function; JTCI = Junior Temperament and Character Inventory; BRI = Behavior Regulation Index; MI = Metacognition Index. *p < .05. **p < .01. ***p < .001.

Table 3.  Factorial Structure Based on BRIEF and JTCI Scales (N = 111). Factor 1 BRIEF   Behavior Regulation Index   Inhibit   Shift   Emotional Control   Self-Monitor   Metacognition Index   Initiate   Working memory   Plan/Organize    Organization of Materials   Task Monitor JTCI  Temperament   Novelty Seeking   Harm Avoidance   Reward Dependence   Persistence  Character   Self-Directedness   Cooperativeness   Self-Transcendence

Factor 2

Factor 3

Factor 4

.725 .508 .747 .655

.545 .316

       

.739 .996 .856 .687 .740

.327

.994 .968 −.425 −.611 −.426 −.826

         

    .614 .359 .371   .925

Note. Principal components analysis with promax rotation. Factor 1 = cognitive regulation problems, Factor 2 = behavior regulation problems, Factor 3 = anxious/rigid, Factor 4 = strengths and resources. Explained variance: Factor 1 = 42%, Factor 2 = 12.1%, Factor 3 = 9.7%, Factor 4 = 7.2%. Factor loadings > .03. BRIEF = Behavior Rating Inventory of Executive Function; JTCI = Junior Temperament and Character Inventory.

7

Drechsler et al. Table 4.  Comparison of Children With ADHD and Clinically Referred Children With Other/No Diagnoses by BRIEF and by JTCI Scales Without (ANOVAs) and With (ANCOVAs) Conduct Disorder (CD/ODD) as Covariate.

  BRIEF (item mean)  BRI   Inhibit   Shift   Emotional Control   Self-Monitor  MI   Initiate   Working Memory   Plan/Organize    Organization of Materials   Task Monitor JTCI scales (T scores)  Temperament   Novelty Seeking   Harm Avoidance   Reward Dependence   Persistence  Character   Self-Directedness   Cooperativeness   Self-Transcendence

ADHD (n = 52)

Non-ADHD (n = 59)

Group effects ANOVAs

M (SD)

M (SD)

F

1.87 (0.41) 1.74 (0.44) 2.00 (0.60) 2.08 (0.65)

1.59 (0.54) 1.70 (0.51) 1.87 (0.56) 1.84 (0.60)

2.251 0.434 1.274 4.352

1.90 (0.37) 2.25 (0.45) 2.06 (0.45) 2.25 (0.58) 2.30 (0.56)

1.67 (0.45) 1.72 (0.51) 1.71 (0.60) 1.71 (0.59) 1.82 (0.56)

56.6 (9.0) 51.6 (10.5) 46.9 (12.2) 36.3 (10.1) 39.6 (8.7) 42.2 (10.2) 43.9 (10.2)

Group effects ANCOVAs ηp2

F

.003* .512 .261 .039

.080 .004 .004 .038

9.601 0.716 1.922 4.655

8.202 32.740 12.437 24.187 21.562

.005* .000* .001* .000* .000*

.070 .231 .102 .182 .165

49.6 (12.4) 54.2 (10.5) 47.9 (11.4) 46.3 (10.8)

11.974 1.311 0.224 26.433

.001* .255 .637 .000*

44.8 (11.2) 46.0 (13.6) 46.6 (11.6)

6.798 2.764 1.312

.010 .099 .255

p

Covariate effects of conduct disorder (CD/ODD) ANCOVAs

ηp2

F

p

ηp2

.002* .399 .168 .033

.082 .007 .018 .042

6.188 5.668 13.610 11.147

.014 .019 .000* .001*

.055 .050 .113 .094

9.330 31.216 11.769 24.908 20.855

.003 .000* .001* .000* .000*

.080 .226 .099 .189 .163

4.458 0.034 0.497 4.337 1,277

.037 .854 .483 .040 .261

.040 .000 .005 .039 .012

.099 .012 .002 .195

15.295 1.481 0.158 26.750

.000* .226 .692 .000*

.125 .014 .001 .200

27.010 0.109 0.008 5.675

.000* .741 .928 .019

.202 .001 .000 .050

.059 .025 .012

7.956 3.874 1.662

.006 .052 .200

.069 .035 .015

5.422 24.258 1.662

.022 .000* .200

.048 .185 .015

p

Note. BRIEF = Behavior Rating Inventory of Executive Function; JTCI = Junior Temperament and Character Inventory; BRI = Behavior Regulation Index; MI = Metacognition Index. p < .05 are indicated in bold. *Significant after correction for multiple comparisons.

(Inhibit, Initiate, Working Memory, Plan/Organize, Organization of Materials, Task Monitor) remained significant after correcting for multiple comparisons. The MANCOVA of the BRIEF scales with conduct disorder (CD/ODD) as a covariate yielded a significant main effect for group, Wilks’s λ = .701, F(9, 100) = 4.670, p < .000, η2p = .298, and a significant effect for conduct disorder (CD/ ODD); Wilks’s λ = .803, F(9, 100) = 2.740, p < . 007, η2p = .199. After correction for multiple tests, the BRIEF scales Inhibit (p < .002), Working Memory (p < .000), Plan/ Organize (p < .001), Organization of Materials (p < .000), and Task Monitor (p < .000) still differentiated significantly between the two groups, with more severe impairment in the ADHD group on all scales. There were significant covariate effects of conduct disorder (CD/ODD) on six of nine scales, but only effects on Emotional Control (p < .000) and Self-Monitor (p < .001) survived correction for multiple tests. Findings from a MANOVA of the seven JTCI scales resulted in a significant main effect, Wilks’s λ = .753, F(7, 103) = 4.816, p < .000, η2p = .247, with significant group differences after correction for multiple testing for Novelty Seeking (p < .001) and Persistence (p < .000; Table 4). MANCOVA of JTCI scales showed a significant difference between groups, Wilks’s λ = .740, F(7, 101) = 5.063, p < .000, η2p = .260, and a highly significant effect of

conduct disorder (CD/ODD); Wilks’s λ = .747, F(7, 101) = 4.894, p < .000, η2p = .253; Table 4. The JTCI Novelty Seeking and Persistence scales discriminated between the ADHD and non-ADHD groups, while highly significant covariate effects of conduct disorder (CD/ODD) were found for Novelty Seeking (p < .000) and Cooperativeness (p < .000). Covariate effects for Persistence and SelfDirectedness did not survive Bonferroni correction.

Discussion In the present study, we examined the overlap between temperament and character according to Cloninger’s personality model and EF problems in everyday life behavior, both rated by parents of clinically referred children. The correlation analyses showed that, as predicted, Novelty Seeking was moderately correlated with all BRIEF BRI scales, but was also correlated, albeit more weakly, with all BRIEF MI scales. Similarly, JTCI Persistence was not only correlated, as predicted, with BRIEF MI scales, but was also weakly correlated with BRIEF BRI scales Inhibit and Emotional control. As shown in previous studies on the hierarchical structure of the BRIEF, the two BRIEF main indices are not independent (Gioia et al., 2000; Gioia, Isquith, Retzlaff, & Espy, 2002). Therefore, a certain overlap of the domains is not surprising. Obviously, cognitive or top-down and

8 behavioral or bottom-up mechanisms of regulation are not as distinctively separated as the concepts suggest, and in some cases, weak control in one domain may induce problems in the other, as proposed by Nigg and Martel (e.g., Martel, Nigg, & von Eye, 2009). In addition, during the course of normal development, top-down regulation should successively gain control over behavioral EF dimensions and bottom-up mechanisms. Only very few of the moderate correlations (r > .05) between BRIEF and JTCI may be explained by the similarity of scale or subscale content (e.g., BRIEF Inhibit vs. JTCI Impulsivity subscale of Novelty seeking; BRIEF Initiate vs. JTCI Purposeful subscale of Self-Directedness). Moderate correlations were also found between scales which present different aspects and levels of self-regulation (e.g., BRIEF Self-Monitor subscale vs. JTCI Novelty Seeking; BRIEF Inhibit vs. JTCI Cooperativeness). BRIEF items are probably more directly based on small portions of observable behavior related to circumscribed cognitive function or disability, and thus more “data-driven” than JTCI items, which more often ask for the classification and interpretation of behavior in an interpersonal context or from an overarching perspective. The character scales were even less clearly attributable to either one of the two BRIEF EF main indices than the temperament scales. The associations between SelfDirectedness and either BRIEF BRI or BRIEF MI were in the same range, with the highest correlation between SelfDirectedness and BRIEF Initiate, which is plausible because both constructs are related to self-initiated and goal-directed behavior. Although JTCI Cooperativeness correlated more highly with BRIEF BRI scales than with BRIEF MI scales, these latter correlations were still significant. Whereas components of temperament may be relatively well associated with either the cognitive or behavioral EF domains of the BRIEF, character dimensions obviously fit less well into this concept. The fact that no EF scale was related to JTCI Self-Transcendence, even though fantasy and make-beliefplay may be associated with EFs (e.g., Berk & Meyers, 2013), can best be explained by the fact that the BRIEF is a mere impairment scale, which does not distinguish between average and above-average performances. Thus, it is less likely that positive traits and strengths will correlate with BRIEF scales. As expected, factor analysis resulted in factors that separated behavioral and cognitive control aspects. EF scales belonging to the BRIEF MI loaded on Factor 1 together with the temperament dimension Persistence, whereas the BRIEF BRI scales loaded on Factor 2 together with JTCI Novelty Seeking. Factor 1 represented cognitive regulation problems typically associated with attention deficits, which may be found in ADHD inattentive and combined presentations (according to DSM-5) and which have been associated

Journal of Attention Disorders  with effortful control (Martel & Nigg, 2006; Nigg et al., 2004). Thus, JTCI Persistence might, to a great extent, represent cognitive control and top-down regulatory mechanisms. Factor 2 indicated impulsive and disruptive behavioral problems, which have been associated with reactive (bottom-up) temperamental traits. As predicted by previous studies (Gioia, Isquith, Retzlaff, & Espy, 2002), BRIEF Monitor subscale items loaded on different factors: Items referring to the control of one’s own work (Task Monitor) loaded on Factor 1, whereas Monitor items referring to the ability to monitor one’s own behavior and the reactions elicited in others (Self-Monitor) loaded on Factor 2. This confirms the different nature of these two types of monitoring suggested by Gioia, Isquith, Retzlaff, and Espy (2002): Lack of care in carrying out tasks and low errormonitoring do not automatically go hand in hand with low sensitivity to the effects of one’s own behavior on others. However, we did not find evidence here for the proposed three-dimensional hierarchical structure of the BRIEF, with Inhibit and Emotional Control loading on separate factors. Factor 3, with the highest loadings on JTCI Harm Avoidance and BRIEF Shift scales, demonstrated an association between anxious/avoidant behavior and mental rigidity, which may be found in patients with obsessive traits or with anxiety or emotional disorders (e.g., Meiran, Diamond, Toder, & Nemets, 2011; Purcell, Maruff, Kyrios, & Pantelis, 1997). Martel and colleagues (2010) described a small group of ADHD children characterized by perfectionism, meaning that this combination of traits may also be present in ADHD. According to Salgado and colleagues (2009), high Harm Avoidance is characteristic of the inattentive subtype in ADHD adults. These first three factors found in the analysis bear some resemblance to the model by Rothbart and colleagues (2004) established for younger children, with its dimensions of executive control, extroversion, and negative affectivity. Finally, Factor 4, representing strengths and resources, did not load on BRIEF scales, and was thus unrelated to problems in executive functioning. While children with ADHD may, of course, dispose of positive resources or may present comorbid internalizing disorders, the appearance of Factors 3 and 4 may be explained in the first instance by the fact that half of the sample consisted of clinically referred children with diagnoses other than ADHD, for example, Pervasive Developmental Disorders or Emotional Disorders, or with no diagnosis. In children with autism, elevated scores on JTCI Harm Avoidance associated with low Reward Dependence and low Self-Directedness have been described (Kerekes et al., 2013, see also Poustka et al., 2011), while on the BRIEF, autism seems to be characterized by clinically elevated scores on the Shift scale and, along with other impairments on the BRIEF MI scales, the Initiate scale (Gilotty, Kenworthy, Sirian, Black, & Wagner, 2002; Gioia,

9

Drechsler et al. Isquith, Kenworthy, & Barton, 2002; Rosenthal et al., 2013). In ADHD as well as in autism, elevated scores on the Shift scale have been linked to anxiety/depression (Lawson et al., 2014). Comorbid anxiety in ADHD seems to aggravate EF deficits as measured by the BRIEF in general, but especially with regard to Inhibition (Sørensen, Plessen, Nicholas, & Lundervold, 2011). Children with ADHD could be distinguished from a clinically referred non-ADHD sample on the BRIEF, as well as on the JTCI. On the BRIEF, all scales of the MI and the Inhibit scale of the BRI differentiated between the groups, which is in line with the previous findings in children with predominantly combined ADHD subtype (DSM-IV; Drechsler et al., 2008; Drechsler & Steinhausen, 2013; Linder et al., 2010; Mahone et al., 2002; Shimoni et al., 2012). Similarly, the ADHD effects on the JTCI for Persistence and Novelty Seeking and Self-Directedness have been reported previously (Cho et al., 2008; Cho, Jung, et al., 2009; Yoo et al., 2006), although in the present sample, Self-Directedness did not survive correction for multiple testing. Possibly, low Self-Directedness is less specific for ADHD compared with high Novelty Seeking or low Persistence, and may be lower than average in the present clinical comparison group. In a recent population-based twin study, Garcia, Anckarsäter, and Lundström (2013) found low Self-directedness in combination with low Cooperativeness to be a general risk factor for psychosocial dysfunction and suffering in children. This might explain why group differences on the Self-directedness scale were less pronounced here than in studies comparing children with ADHD and normal controls. In the present sample, elevated scores on BRIEF Inhibit and Task Monitor were characteristic for ADHD rather than for disruptive behavior disorders, whereas the latter was characterized by elevated scores on the Emotional Control and Self-Monitor scales. This suggests profile differences rather than differences in severity as reported previously (Qian et al., 2010) for conduct disorder (CD/ODD) or ADHD plus disruptive behavior disorders compared with ADHD only on the BRIEF. On the JTCI, Novelty Seeking was significantly and independently related to ADHD as well as to disruptive behavior disorders. This result may explain certain inconsistencies found in the literature concerning the status of elevated Novelty Seeking as a trait marker for ADHD or for disruptive behavior disorder. For example, according to Rettew and colleagues (2004), Novelty Seeking did not discriminate between children with ADHD and controls, but did discriminate between children with disruptive behavior disorders and controls. In preschool children, ODD children have been reported to share high Novelty Seeking with ADHD children, but they were more specifically characterized by higher Persistence and Harm Avoidance, which, according to the study authors,

makes them more resistant to the extinction of non-adaptive behaviors (Melegari et al., 2015). In the present sample, enhanced Novelty Seeking was found in children with ADHD independently of comorbid conduct disorder (ODD/ CD), but it was also a trait marker of conduct disorder (ODD/CD) alone. Low Cooperativeness, in contrast, was clearly associated with disruptive behavior disorders and not with ADHD, whereas low Persistence was more specifically related to ADHD.

Conclusion There is a consistent overlap between Cloninger’s temperament and character dimensions, and EF components as assessed by the BRIEF according to parent ratings. This is partly due to the fact that BRIEF EF scales comprise behavioral aspects of self-regulation as well as cognitive aspects, which may be linked to the temperament dimensions of Novelty Seeking and Persistence, respectively. However, the two instruments contribute differentially to the description of children’s mental health problems: While the BRIEF is a clinical scale indicating impairment, the JTCI explores deficits as well as strengths and resources. Only a minority of scales or subscales of the BRIEF and the JTCI show a direct overlap, as indicated by at least moderate correlations (e.g., BRIEF Initiate vs. JTCI SelfDirectedness/Goal-Directedness). In general, the BRIEF scales seem to cover an EF construct situated on an intermediate level between self-regulatory dysfunction, as measured by objective EF tests and the JTCI measuring behavioral tendencies and regulation from a more comprehensive interpersonal and contextual perspective. These broader aspects are not covered by BRIEF scales. Although both instruments distinguish reliably between children with and without ADHD, different aspects are highlighted. The BRIEF focuses on a detailed deficit profile of regulatory functions, from which immediate consequences for behavioral/cognitive training may be deduced. For instance, children with ADHD need to be trained to control their work more systematically for errors, whereas children with conduct disorders (ODD/CD) or ADHD plus ODD/CD need to improve self-awareness and awareness of how they are perceived by others. JTCI results, in contrast, offer a broader understanding of general and time-enduring traits and behavioral dispositions of a child with ADHD in the context of neurodevelopmental disorders. The two scales make differential contributions to the description and delineation of ADHD compared with disruptive behavioral disorders. Therefore, BRIEF and JTCI may be seen as complementary. To further clarify the relationship between temperament, character, and EF deficits in ADHD and related disorders and to describe possible subgroups or patterns, cluster analyses should be performed based on larger groups of patients,

10 including data based on the JTCI, the BRIEF and performance-based EF measures. Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.

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Author Biographies Renate Drechsler, PhD, is senior researcher at the Department of Child and Adolescent Psychiatry, University of Zurich, and lecturer at the Psychology Department of the University of Zurich, Switzerland. She graduated in linguistics and psychology and specialized in clinical neuropsychology. Her current research interests include neuropsychological aspects of ADHD, interventions for children with ADHD, executive functions, emotion processing, and neuropsychological assessment. Marina Zulauf Logoz, PhD, is a clinical child psychologist at the Department of Child and Adolescent Psychiatry, University of Zurich, and a lecturer at the Faculty Medicine of the University of Zurich, Switzerland. She graduated with a diploma in clinical psychology (Marburg, Germany) and with a PhD in developmental psychology in Zurich, specializing in attachment research and theory. Her interests in research and in clinical practice include child attachment issues and anxiety disorders in childhood. Susanne Walitza, MD, MSc, is full Professor and the Medical Director of the Department of Child and Adolescent Psychiatry, University of Zurich, Switzerland. Her current research interests include clinical pictures and phenotyping, using psychological and neuropsychiatric aspects, as well as the genetics and neuroimaging of ADHD, OCD, and other developmental disorders in child and adolescent psychiatry and psychotherapy. Hans-Christoph Steinhausen, MD, PhD, is Professor and Chairman Emeritus at the Department of Child and Adolescent Psychiatry, University of Zurich, Switzerland, Honorary Professor at the Institute of Psychology, University of Basel, Switzerland, and Professor of Child and Adolescent Psychiatry at Aalborg Psychiatric Hospital, Aarhus University Hospital, Denmark. He graduated with an MD in medicine (1970), a PhD in psychology (1975), and a postdoctoral dissertation in medicine (DMSc 1976). His current major research interests include developmental psychopathology and various neuroscientific, genetic, and clinical issues in child and adolescent psychopathology.