Figure 1.

Correlation between clinical predictors and response to lithium treatment. Shown is the meta-analytic effect size (r) for the clinical predictors by descending order of strength. A positive r value indicates a positive correlation between the clinical predictor and a positive response to lithium. A negative r value indicates a negative correlation between the clinical predictor and a positive response to lithium. Meta-analysis performed under a random effects model as described by Kleindienst and colleagues [Kleindienst et al. 2005]. The result for age at onset has been updated to include three additional papers examining this relationship. DMI, depression-mania-free interval; MDI, mania-depression-free interval.