Cognitive deficits in adults with ADHD go beyond comorbidity effects.

OBJECTIVE: This study addresses if deficits in cognitive, attention, and inhibitory control performance in adults with ADHD are better explained by the disorder itself or by comorbid conditions. METHOD: Adult patients with ADHD (n = 352) and controls (n = 94) were evaluated in the ADHD program of a tertiary hospital. The diagnostic process for ADHD and comorbidities was based on Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria. Stepwise regression analyses evaluated the effect of ADHD, demographics, and comorbidities on the scores from Wechsler Adult Intelligence Scale-Revised, Continuous Performance Test, and Stroop Color and Word Test. RESULTS: Patients with ADHD of both genders had worse performance on neuropsychological domains, even after adjustment for comorbidities. The presence of comorbid bipolar disorder and specific phobia are associated with more Stroop errors, whereas patients with generalized anxiety disorder present a longer execution time in Stroop. CONCLUSION: Neuropsychological deficits in adults with ADHD go beyond comorbidity. Specific comorbid disorders may influence the neuropsychological functioning in adults with ADHD.

Does age of onset of impairment impact on neuropsychological and personality features of adult ADHD?

The consideration of age of onset of impairment as part of the ADHD diagnosis is controversial and has been a revisited issue with the emergence of the new classifications in Psychiatry. The aim of this study is to compare patients with early and late onset of ADHD impairment in terms of neuropsychological and personality characteristics. Adult patients with ADHD (n = 415) were evaluated in the ADHD outpatient program at Hospital de Clínicas de Porto Alegre, Brazil. The diagnostic process for ADHD and comorbidities was based on DSM-IV criteria. The comparison between the two ages of onset groups (before 7; n = 209 or from 7 to 12 years; n = 206) was performed with ANOVA, followed by Stepwise forward regression analyses to restrict the number of comparisons and access the possible effect of multiple confounders. Patients with early onset ADHD present higher scores in novelty seeking in both analyses (respectively P = 0.016 and P = 0.002), but similar cognitive and attention features as compared with the late onset group. These data add to previous evidence that despite a more externalizing profile of early onset ADHD, the overall performance is similar reinforcing the need for awareness and inclusion of the late onset group in DSM-V diagnostic criteria.

Inattention and hyperactivity dimensions of ADHD are associated with different personality profiles.

BACKGROUND: Previous studies have suggested that individuals with ADHD have high scores in novelty seeking and harm avoidance. However, it is not known whether personality is associated with specific subtypes and dimensions of the disorder. The aim of this study is to test for associations between scores in the temperament and character inventory of C.R. Cloninger with adult ADHD subtypes and severity. SAMPLING AND METHODS: The diagnostic interviews of 296 adult ADHD patients followed the DSM-IV criteria. ADHD dimensions were evaluated with the SNAP-IV scores, and personality dimensions were assessed using the Temperament and Character Inventory. RESULTS: The combined subtype (n=168) was associated with higher scores in novelty seeking (p<0.001) and lower scores in cooperativeness (p=0.006) than the inattentive subtype (n=128). Higher inattention scores were associated with decreased self-directedness (p<0.001) and increased harm avoidance (p=0.02), whereas higher hyperactivity/impulsivity scores correlated positively with novelty seeking (p<0.001) and persistence (p=0.03). CONCLUSIONS: These findings suggest that personality dimensions are strongly correlated with ADHD subtypes and severity dimensions, pointing to the need for studies evaluating the mechanisms behind this association.

Smoking is associated with lower performance in WAIS-R Block Design scores in adults with ADHD.

Adults with attention-deficit/hyperactivity disorder (ADHD) are predisposed to smoking, but the neuropsychological correlates of this association have not been elucidated so far. The present study evaluates possible associations between cognitive performance and smoking and other comorbidities in adults with ADHD. Two hundred and sixty-four (264) patients were evaluated in the adult ADHD outpatient clinic of the Hospital de Clínicas de Porto Alegre. The diagnoses were based on the DSM-IV criteria and interviews were performed with the Portuguese version of K-SADS-E for ADHD and oppositional-defiant disorder. Axis I psychiatric comorbidities were evaluated with the SCID-IV and the cognitive performance with the Vocabulary and Block Design subtests of the Wechsler Adult Intelligence Scale-Revised (WAIS-R). The evaluation of the influence of the WAIS-R scores on each dependent variable was performed with logistic regression analyses. Lower scores in the Block Design subtest of WAIS-R were associated with smoking and the presence of anxiety disorder. These results suggest that a subgroup of ADHD patients with lower Block Design subtest scores may be at increased risk of smoking as a cognitive enhancement. Our findings also confirmed the previously suggested association between anxiety and lower Block Design scores.

The role of comorbid major depressive disorder in the clinical presentation of adult ADHD.

Most adults with attention-deficit/hyperactivity disorder (ADHD) are not recognized and remain untreated, although a large fraction of these individuals are diagnosed and treated for other comorbid mental disorders, such as major depressive disorder (MDD). The fact that MDD is one of the most commonly occurring mental disorders with high comorbidity with adult ADHD raises the question whether such comorbidity is associated with differences in the clinical picture of ADHD. Three hundred and twenty adult ADHD outpatients were evaluated. Diagnoses followed DSM-IV criteria. Interviews to evaluate ADHD and oppositional defiant disorder (ODD) were performed based on the Portuguese version of K-SADS-E. Psychiatric comorbidities were investigated using SCID-IV and MINI. Regression models were applied to test MDD association with clinical and demographic outcomes. Subjects presenting ADHD and MDD had a higher frequency of generalized anxiety disorder and social phobia and a lower frequency of substance dependence, grade repetition and school suspensions, when compared to subjects with ADHD without MDD. Furthermore, adults presenting ADHD and MDD reported higher demand for psychotherapy and pharmacological treatment prior to enrollment in the study when compared to ADHD subjects free of MDD. However, contrary to what could be expected based on these data, the presence of MDD was not associated with an earlier ADHD diagnosis. These results point to the need for research and medical education into an earlier and more efficient ADHD diagnosis in patients who search for mental health care.

Lack of gender effects on subtype outcomes in adults with attention-deficit/hyperactivity disorder: support for the validity of subtypes.

The aim of the present study is to verify if gender modifies the clinical, adaptative and psychological outcomes of adult attention-deficit/hyperactivity disorder (ADHD) subtypes. We evaluated 219 clinically referred adult patients. The interviews followed the DSM-IV criteria,using the K-SADS-E for ADHD and oppositional defiant disorder and SCID-IV for comorbidities. Regression models were used to analyze gender and subtype main effects and interactions in psychiatric outcomes. In the initial sample, 117 patients (53.5%) were of the combined subtype, 88 (40%) were inattentives and 14 (6.5%) hyperactives. There were no significant interactions between gender and subtype in any variable assessed. Men and women did not differ in the relative frequency of each subtype. Patients of the combined subtype in both genders presented a higher severity and increased rates of conduct and ODD disorders than inattentives. The main effects of gender and subtype in this sample are similar to those previously reported in other countries, suggesting the cross-cultural equivalence of the phenotype. The absence of significant interactions between gender and subtype suggests that, at least in clinical-based samples, DSM-IV adult ADHD subtypes present cross-gender validity.