Ages of onset and rates of syndromal and subsyndromal comorbid DSM-IV diagnoses in a prepubertal and early adolescent bipolar disorder phenotype.

OBJECTIVE: To study rates and ages of onset of DSM-IV syndromal and subsyndromal comorbidity in a prepubertal and early adolescent bipolar disorder phenotype (PEA-BP) (N = 93) compared to attention-deficit/hyperactivity disorder (ADHD) (N = 81).
METHOD: The WASH-U-KSADS was given by raters blinded to subject group separately to mothers about their children and to children about themselves. PEA-BP was defined as DSM-IV mania with at least one cardinal symptom of mania (elation or grandiosity) to avoid diagnosing using only symptoms that overlapped with those for ADHD. Syndromal diagnoses required a CGAS score of 60 or less to ensure severity at a level of definite "caseness."
RESULTS: PEA-BP subjects were aged 10.9 (SD = 2.6) at baseline and 6.8 (SD = 3.4) at onset of first mania episode. Rates of oppositional defiant disorder and total number of comorbidities were significantly higher in the PEA-BP group than the ADHD group. In PEA-BP subjects, mean ages of onset of ADHD occurred before the first manic episode, and obsessive compulsive, oppositional defiant, social phobia, generalized anxiety, separation anxiety, and conduct disorders occurred after.
CONCLUSIONS: Onsets of ADHD before mania and of oppositional defiant disorder/conduct disorder after mania have clinical and research implications. These include the need to examine for mania symptoms in children with ADHD and/or oppositional defiant disorder/conduct disorder and to develop scales to differentiate preschool mania from ADHD. Comparison with other studies demonstrated the importance of DSM system and severity scales in reporting comorbidity rates.