Neuropsychopharmacology, 2011, Volume 36 .  Wuerzburg, Germany.

Both attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder have been found to possibly be located in the same genetic region known as the 4p16 region.  I a study published in the journal Neuropsychopharmacology, a total of 513 in-and outpatients affected with adult ADHD were studied.  There were 536 controls and 170 nuclear families with 249 children affected with ADHD.

The study found that co-morbidity between bi-polar disorder and attention-deficit/hyperactivity disorder is thought to be a common phenomenon.   Univ. Wuerzburg Article Here.McGough et al. reported that 87% of the unitary affected parents of children with ADHD had at least one and 56% had at least two other psychiatric disorders. While the clinical relevance of psychiatric co-morbidity is acknowledged in children, it has remained controversial in adult ADHD