Predictive familial risk factors and pharmacological responses in ADHD with comorbid disruptive behavior disorders

The aim of the present study was to examine the putative familial risk factors and evaluate the pharmacological effects in children and adolescents of attention-deficit-hyperactivity disorder (ADHD) with comorbid disruptive behavior disorders (DBD) and normal IQ.

The retrospective study included 144 Japanese subjects (age, 5-18 years) with ADHD, of whom 35 subjects (24%) met the diagnostic criteria for DBD. Using multiple regression analysis, the familial background risk factors that might increase any comorbid antisocial behaviors were assessed. Furthermore, the 20 methylphenidate (MPH)-resistant DBD subjects were divided into three treatment groups: MPH plus risperidone (n= 8); MPH plus carbamazepine (n= 5); and MPH plus lithium carbonate (n= 4). The effectiveness of the treatment was evaluated both before and after the add-on therapy using the Clinical Global Impressions-Improvement (CGI-I) and CGI-Severity (CGI-S) scale.

The putative familial risk factors were child abuse (odds ratio [OR], 19.48; P= 0.013) and maternal psychiatric disorders (OR, 15.59; P= 0.027). The addition of risperidone had the strongest tendency to improve the CGI-S score (P= 0.063) and the highest rate of responses (50%) among the three treatment groups, albeit with no significant differences. Very few remarkable adverse clinical symptoms were observed.

Child abuse and maternal psychiatric disorders are suggested to be significant risk factors in influencing the development of comorbid DBD in offspring. The use of risperidone appears to be well tolerated and is moderately effective in MPH-resistant aggression in ADHD children and adolescents with comorbid DBD.