Question: Does lithium increase risk for adverse events in patients with depression, bipolar disorder, or schizoaffective disorder? Review scope: Included studies assessed the association between lithium and ≥ 1 of the specified adverse events in patients with depression, bipolar disorder, or schizoaffective disorder. Outcomes included renal function (glomerular filtration rate [GFR] and urinary concentrating ability), thyroid function (thyroid-stimulating hormone), subclinical or clinical hypothyroidism, hyperthyroidism, parathyroid function (total calcium and parathyroid hormone [PTH]), weight change (> 7% change in total weight in kg), and skin disorders. Review methods: MEDLINE, EMBASE/Excerpta Medica, CINAHL, PsycINFO, Cochrane Library, Biosis Previews, and TOXNET database (all to 2010); Lithium, Lithium Therapy Monographs, and Teratology; reference lists; textbooks; and conference abstracts were searched for randomized controlled trials (RCTs), prospective cohort studies, case-control studies, uncontrolled prospective cohort studies, or case reports. Manufacturers of lithium, clinical experts, and authors were contacted. 22 RCTs; 197 case-control, uncontrolled cohort, or cross-sectional studies; and 166 case reports met inclusion criteria. The authors reported the results of the highest level of evidence for each outcome. Only results of meta-analyses of RCTs or case-control studies are reported in this abstract. Main results: The main results are reported in the Table. Conclusions: Meta-analysis of randomized controlled trials showed that lithium is associated with increased risk for weight gain compared with placebo. Meta-analyses of case-control studies showed that lithium increases risk for reduced urinary concentrating ability, hypothyroidism, and hyperparathyroidism but not glomerular filtration rate.