Factors associated with discontinuation of long-term lithium treatment.

Sixty-four outpatients with major affective disorder according to DSM-III and on continuous lithium treatment for an average duration of 7.8 years were first investigated in 1980 and then followed for 7 years. The predictive value of patients' attitudes to their lithium, the prognostic influence of psychiatric status, side effects, and anamnestic and laboratory data including lithium parameters were studied. At the end of the 7-year follow-up, 61% of the patients were still on lithium maintenance treatment, 25% had discontinued lithium for clinical reasons, and 14% of the patients had died. Side effects of lithium were the major clinical reason for discontinuing treatment, while attitudes towards medication were of minor importance. Approximately one fourth of the patients who discontinued lithium were differentiated from those who continued treatment by showing a high frequency of the neurologic side effects incoordination, paresthesia, and disturbed sensibility in addition to having more severe tremor. In yet another fourth of those who discontinued for clinical reasons, lithium was stopped by the treating psychiatrist as maximal urine osmolality values were considered to be too low. These patients did not show any signs of clinically significant impairment of renal functions. Their psychiatric status was excellent in terms of extremely low CPRS scores. The patients who died during the follow-up period were differentiated from those who continued treatment by a much higher frequency of alcohol and drug abuse prior to the initiation of lithium therapy. The total number of side effects and the number of severe side effects were significantly larger than in continuers on lithium. The most common causes of death were cardiovascular disease and suicide. In no case was the cause of death attributed to lithium therapy.