Trends and determinants of prescription of lithium and antidepressants for bipolar disorder in a large health care system between 2017 and 2022

Background

Previous studies raised concerns about declining use of lithium and increased use of antidepressants in treatment of bipolar disorder (BP). We describe recent trends in prescription of psychotropic medications for BP and examine demographic, socioeconomic and clinical factors associated with their prescription.

Methods

We analyzed data from the electronic health records on 12,824 patients with BP in a large academic health system between 2017 and 2022. We calculated annual prescription rates for BP medications, and then used logistic regression to examine factors associated with their prescription.

Results

We found a modest increase in lithium prescription and a slight decrease for antidepressants. Lithium was prescribed to 27 % of patients, while antidepressants were prescribed to 52 % of patients, nearly half without a concomitant mood stabilizer. Patients who were Black (odds ratio [OR] = 0.70 95 % confidence interval [CI] = 0.65–0.76), had public insurance (OR = 0.87, 95 % CI = 0.81–0.94), lived in areas of higher social deprivation (OR = 0.84, 95 % CI = 0.76–0.93), or were seen in primary care (OR = 0.21, 95 % CI = 0.17–0.24) were less likely to be prescribed lithium. Patients who lived in areas of greater deprivation (OR = 1.42, 95 % CI = 1.20–1.68), were older (60+; OR = 2.64, 95 % CI = 1.96–3.58), and were seen in primary care (OR = 7.46, 95 % CI = 6.43–8.66) were more likely to be prescribed antidepressants without a concomitant mood stabilizer.

Conclusions

Lithium remains underutilized even though it is a first-line treatment for BP, especially among certain sub-groups. Antidepressants are widely used to treat BP, often without mood stabilizers despite caution by most clinical guidelines. These findings underscore the need for continued efforts to promote use of best evidence-treatments for BP and reduce disparities in their use.