Introduction Lithium is established as an effective treatment of mania, of depression in bipolar and unipolar disorder, and in maintenance treatment of these disorders. However, due to the necessity of monitoring and concerns about irreversible adverse effects, in particular renal impairment, after long-term use, lithium might be underutilized.
Methods This study reviewed 6 large observational studies addressing the risk of impaired renal function associated with lithium treatment and methodological issues impacting interpretation of results.
Results An increased risk of renal impairment associated with lithium treatment is suggested. This increased risk may, at least partly, be a result of surveillance bias. Additionally, the earliest studies pointed toward an increased risk of end-stage renal disease associated with lithium treatment, whereas the later and methodologically most sound studies do not.
Discussion The improved renal outcome found in the more recent lithium studies may be a result of improved monitoring and focus on recommended serum levels (preferentially 0.6-0.8mmol/L) as compared to poorer renal outcome in studies with patients treated in the 1960s to 1980s.