Neurocognitive impairment in patients with co-occurring bipolar disorder and alcohol dependence upon discharge from inpatient care

The current study explored the neurocognitive functioning of patients with co-occurring bipolar disorder and alcohol dependence upon discharge from inpatient care. The study compared scores of neuropsychological tests among three groups of bipolar I inpatients without a history of neurological injury or illness: 1) patients meeting DSM-IV diagnostic criteria for alcohol dependence in the past 6 months (n=13), 2) patients diagnosed with alcohol dependence in full remission (n=9), and 3) patients without a history of a substance use disorder (SUD; n=41). Analyses indicated that patients with co-occurring alcohol dependence exhibited more severe impairment on tests of executive functioning (i.e. Stroop Color-Word Interference Test, Wisconsin Card Sorting Test) than patients without SUD. In addition, the group meeting diagnostic criteria for alcohol dependence in the past 6 months exhibited greater decrements in verbal (California Verbal Learning Test--II) and visual (Rey Complex Figure Test) memory. Analysis further indicated that patients in full SUD remission scored lower on measures of fluid intelligence (Wechsler Abbreviated Scale of Intelligence--Performance IQ). Consistent with previous reports, in the current sample, co-occurring alcohol dependence predicted higher rates of disability status. It is possible that cognitive deficits of greater severity in dually diagnosed patients contribute to this unfavorable outcome. Recognizing the extent of cognitive impairment in dually diagnosed patients may facilitate the effort to ameliorate their condition.