Neurological abnormalities in drug-free and drug-treated patients with bipolar affective disorder

Objective: To assess the effect of medication on neurological abnormalities in patients with bipolar affective disorder. Patients and Methods: Neurological abnormalities were examined in 30 drug-free patients and 30 drug-treated patients meeting Diagnostic and Statistical Manual of Mental Disorders, 4th edition diagnostic criteria for bipolar affective disorder, and 20 age- and sex-matched controls, using the Extended Standard Neurological Assessment Instrument. Mania and depression were assessed using the Young Mania Rating Scale and the Hamilton Rating Scale for Depression, respectively. Side effects of medications were assessed using the Udvalg for Kliniske Undersøgelser Side Effect Rating Scale. Results: Patients with bipolar affective disorder had higher mean total scores on the Extended Standard Neurological Assessment Instrument (drug-free group 22.83 ± 11.04, drug-treated group 22.00 ± 10.23) than controls, who did not score on any items of the neurological battery. There was a significant excess of hard signs and involuntary movements in the drug-treated group compared with the drug-free group, and a significant positive correlation between hard signs and the involuntary movements score and the neurological subscore on Udvalg for Kliniske Undersøgelser Side Effect Rating Scale in the drug-treated group. Conclusion: The presence of neurological signs in drug-free patients with bipolar affective disorder suggests that neurological abnormalities may occur independently of medication effects. Side effects of drug treatment for bipolar affective disorder may contribute to the prevalence of neurological abnormalities in this patient population.