Risk for switch from unipolar to bipolar disorder in youth with ADHD: A long term prospective controlled study
Received 21 January 2009; received in revised form 6 February 2009; accepted 19 February 2009.
Abstract
Background
To investigate whether ADHD is a risk factor for switches from unipolar to bipolar disorder over time.
Methods
Data from two large controlled longitudinal family studies of boys and girls with and without ADHD and their siblings were used. Subjects (n=168) were followed prospectively and blindly over an average follow-up period of 7 years. Comparisons were made between youth with unipolar major depression who did and did not switch to full or subthreshold BP-I disorder at the follow-up assessment. Subjects were assessed at baseline and follow-up on multiple domains of functioning. Positive family history of parental psychiatric disorders was also compared between groups.
Results
ADHD was associated with a significantly higher risk for switches from unipolar to bipolar disorder (28% versus 6%; z=2.80, p=0.005). In subjects with ADHD, switches from unipolar to bipolar disorder were predicted by baseline comorbid conduct disorder, school behavior problems, and a positive family history of parental mood disorder.
Limitations
Psychosis was an exclusionary criterion in the original ascertainment of the studies of ADHD probands, so we were unable to test this as a predictor of switching to BPD.
Conclusions
ADHD is a risk factor for switches from unipolar to bipolar disorder, and switches could be predicted by the presence of baseline conduct disorder, school behavior problems, and a positive family history of a mood disorder in a parent. These characteristics can aid clinicians in their treatment of youth with MDD.
aClinical and Research Program in Pediatric Psychopharmacology, Massachusetts General Hospital, United States
bDepartment of Psychiatry, Massachusetts General Hospital, United States
cDepartment of Psychiatry, Harvard Medical School, Boston, MA, United States
dDepartment of Psychiatry, SUNY Upstate Medical University, Syracuse, NY, United States
eDepartment of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY, United States
Corresponding author. Clinical and Research Program in Pediatric Psychopharmacology Yawkey Center Suite 6A Massachusetts General Hospital, Fruit Street, Boston, MA 02114, United States. Tel.: +1 617 726 2724.
ABSTRACT