Lithium prophylaxis of recurrent bipolar affective disorder: long-term outcome and its psychosocial correlates.

BACKGROUND: Discrepancy between efficacy of prophylactic lithium and its effectiveness in ordinary clinical practice necessitates long-term follow-up data from specialised lithium clinics. Also, role of psychosocial factors in influencing the outcome is unclear.
METHODS: One hundred and eighteen patients of bipolar affective disorder attending a lithium clinic were followed-up for approximately 11 years (range 2-27 years). Demographic and clinical data, measures of social support and psychosocial stress were obtained at the intake in 1989-1990. Study design combined retrospective chart-review (till the time of intake) with prospective follow-up till July 1995.
RESULTS: On lithium, the patients had a mean of 0.43 relapses per year (manic, 0.26; depressive, 0.17) which was significantly less (p < 0.01) than the pre-lithium episode frequency. The figure for entirely relapse-free patients was 24%, and 62% had relapses up to one episode per year (median = 0.3 per year). Fifty-eight (49%) patients were good responders to lithium (relapses < or = 0.30 per year). In comparison to good responders, partial/poor responders had a significantly greater number of pre-lithium depressive episodes, poor lithium compliance, more psychosocial stress and lower social support at intake. These variables correlated well with relapses and explained 32% of the variance of the data.
CONCLUSIONS: Lithium had a definite prophylactic effect on long-term outcome. Social support and stressful life events are significant correlates of response to lithium. CLINICAL IMPLICATIONS: Lithium prophylaxis of bipolar affective disorders seems justified though psychosocial factors appear to modulate its effectiveness. LIMITATIONS: Other psychotropic medications were used during relapse and the assessment of psychosocial factors was cross-sectional.