Background: The aim was to systematically integrate the available evidence on psychosocial and demographic factors associated with response prediction to prophylactic lithium.
Method: Each psychosocial or demographic variable that was related to lithium response in at least one study was examined with respect to response prediction. If several studies were located for the same variable results were integrated using a meta-analytical approach. To account for heterogeneity of primary studies aggregation of results was based on a random-effects model.
Results: Out of 27 psychosocial and demographic variables investigated in this review, nine variables were identified as significantly related to outcome under to prophylactic lithium: (1) high social status, (2) social support, (3) good compliance, and (4) dominance may be protective against a recurrence under lithium. In contrast, (5) stress, (6) high expressed emotions, (7) neurotic personality traits, (8) unemployment, and (9) a high number of life events were identified as possible risk factors for poor response.
Conclusions: This systematic review shows a surprisingly high number of psychosocial variables to be related to lithium response. Effect sizes were, however, small to moderate. Many variables should, therefore, be considered simultaneously to predict response.