Lithium for schizophrenia

The update search in 2006 did not detect further studies that met our inclusion criteria. The review thus still includes 20 studies with a total of 611 participants. Most studies were small, of short duration and incompletely reported, but a number of authors were willing to share their data with us. Three studies comparing lithium with placebo as the sole treatment showed no difference in any of the outcomes we analysed. In eight studies comparing lithium with antipsychotic drugs as the sole treatment, more participants in the lithium group left the studies early (n=270, RR 1.8, CI 1.2 to 2.9, NNT 9, CI 5 to 33). Several of the outcomes relating to these studies suggested that lithium is less effective than antipsychotic drugs, but it was difficult to summarise the data because a variety of rating scales were used in the studies. Eleven studies examined whether the augmentation of antipsychotic drugs with lithium salts is more effective than antipsychotic drugs alone. More participants who received lithium augmentation had a clinically significant response (n=244, RR 0.8, CI 0.7 to 0.96, NNT 8, CI 4 to 33). However, statistical significance became borderline when participants with schizoaffective disorders were excluded in a sensitivity analysis (n=120, RR 0.8, CI 0.6 to 1.0, p=0.07). Furthermore, more participants in the lithium augmentation groups left the studies early (n=320, RR 2.0 CI 1.3 to 3.1, NNT 7, CI 4 to 14), suggesting a lower acceptability of lithium augmentation compared to those on antipsychotics alone. No superior efficacy of lithium augmentation in any specific aspect of the mental state was found. While based on very little data, there were no differences between groups for adverse events.