The Impact of Lifetime ADHD on Neuropsychological Functioning in Young Adults with Bipolar Disorder: A Comparison of Bipolar Disorder with and without Childhood ADHD, ADHD, and Control Groups.
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
Almost all neuropsychological studies of adult bipolar disorder (BP) have failed to control for the established cognitive effects of attention deficit hyperactivity disorder (ADHD), and often other covariates. ADHD comorbidity in BP is common, and has already been shown to significantly worsen the clinical presentation of BP. This study of young adults (16 - 34 years) aimed to establish whether ADHD and BP with childhood ADHD groups had more impaired cognitive profiles (after controlling for numerous covariates) relative to BP without childhood ADHD and control groups. Using recognised structured and semi-structured clinical interviews and symptom rating scales, BP with (n = 18) or without (n = 66) childhood ADHD groups were recruited from a therapy study, and ADHD (n = 27) and control (n = 26) groups were recruited from the community. Participants completed tests (some from the Cambridge Neuropsychological Test Automated Battery) of executive functioning, memory, attention and psychomotor speed. MANCOVA results for cognitive performance indicated that the BP with childhood ADHD group did not differ significantly from the other three groups (except on a test of visual object memory, where it outperformed the ADHD group). The ADHD group was impaired relative to the BP without childhood ADHD and control groups on measures of verbal and visual memory. It was also more impaired than controls on a measure of attention. The BP without childhood ADHD group had visual memory and attention difficulties relative to controls. Compared to BP (controlling for ADHD), ADHD is associated with a more diverse range of cognitive impairment. Nevertheless, individuals with BP may independently demonstrate memory and attention difficulties which have the potential to interfere with treatment and day-to-day functioning.