Psychotropic drugs and personality changes: A case of lithium

The 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.

The 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.

Patients 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.

It 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.