Effects of long-term lithium therapy on kidney functioning in mood disorders: A population-based historical cohort study.

Aims: Lithium is Food and Drug Administration-approved for bipolar disorder (BD) and is also used in depressive disorders but is underutilized due to concerns about chronic kidney disease (CKD). We explored clinical and demographic profiles of patients on long-term lithium therapy (LTLT) and assessed kidney function. Our aims were to identify the predictors for CKD stage ≥3 and the impact of lithium discontinuation post-CKD diagnosis.

Methods: We conducted a population-based historical cohort study of adult patients with mood disorders on LTLT at the Marshfield Clinical Health System from 1990 to 2019. Data on lithium therapy and kidney-related information (estimated glomerular filtration rate and CKD) were extracted from electronic medical records.

Results: Among 1603 patients with mood disorders (mean age 42.1 years, 60% females), 15.3% (n = 246) developed CKD stage ≥3. Patients without CKD were on lithium for 4.5 years, compared to 6.6 years for those with CKD. Hypertension, age, and BD were significant CKD risk factors. Kidney function declined linearly with lithium duration, returning to pre-treatment trajectory in patients without CKD but showed no improvement in those with CKD after lithium discontinuation.

Conclusion: The findings suggest that CKD occurs in 15% of patients with mood disorder receiving LTLT, with its progression potentially influenced by existing comorbidities rather than lithium alone. These results underscore the importance of monitoring kidney function in patients on LTLT and considering individual risk factors for CKD development. In patients who developed CKD, Li discontinuation did not impact change in kidney function.