Attention-deficit/hyperactivity disorder and comorbidity in Brazil: comparisons between two referred samples

The aim of this study was to compare the pattern of comorbidity in referred samples of Attention-Deficit/Hyperactivity Disorder (ADHD) patients from two different geographic areas in Brazil.

The diagnoses of ADHD and comorbid conditions, according to DSM-IV criteria, were achieved in both clinics through semi-structured interview methodology, complemented by clinical interviews with the children or adolescents and their parents.

We assessed 343 ADHD children and adolescents in Porto Alegre (capital of the southernmost state of the country) and 78 ADHD youths in Rio de Janeiro (capital of a southeastern state). Although a significant difference in the prevalence of ADHD without comorbidity was detected between the two groups (p = 0.02), no significant difference was detected in the profile of comorbidities between them. Main ADHD comorbidities in both samples were: a) Oppositional Defiant Disorder (Porto Alegre = 39.1%; Rio de Janeiro = 51.3 %); b) Anxiety Disorders (Porto Alegre = 24.2%; Rio de Janeiro = 30.8 %); c) Conduct Disorder (Porto Alegre = 13.7%; Rio de Janeiro = 17.9 %); and d) Major Depression and/or Dysthymia (Porto Alegre = 11.4%; Rio de Janeiro = 10.3 %).

Our results from clinical samples in a developing country with a diverse culture suggest the crosscultural validity of the ADHD comorbidity profile.