Psychotropic drugs and personality changes: A case of lithium

BackgroundThe effect of psychopharmacological treatment on personality has been mostly studied with antidepressant drugs. Previously, we demonstrated an association between long-term lithium response and affective temperaments measured by the Temperament Scale of Memphis, Pisa, Paris and San Diego-Autoquestionnaire (TEMPS-A), and schizotypic traits, measured by the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE). Therefore, we were interested whether long-term lithium treatment per se may influence personality traits measured by these scales.MethodsThe study was performed on 40 patients with bipolar mood disorder (16 male, 24 female) with a mean age of 46 ± 10 years, either hospitalized or attending the outpatient clinic, Department of Adult Psychiatry, Poznan University of Medical Sciences. Among them, twenty patients (8 male, 12 female) have received lithium for 10–33 years, and twenty (8 male, 12 female) have never been exposed to lithium and have been given other mood-stabilizing drugs. Each patient, had the assessment made by the TEMPS-A and O-LIFE, during euthymic state.ResultsPatients on long-term lithium treatment were significantly older and had longer duration of bipolar illness compared with non-lithium patients. Lithium-treated patients obtained significantly lower scores of cyclothymic and irritable temperaments on the TEMPS-A, and of unusual experiences, cognitive disorganization and impulsive nonconformity on the O-LIFE.ConclusionsIt is hypothesized that the differences in personality, revealed by the TEMPS-A and O-LIFE scales, are related to the long-term treatment with lithium. The decrease in cyclothymic temperament and in cognitive disorganization trait were previously shown to be associated with the therapeutic effect of lithium.