Response and Adverse Effects to Lithium Treatment in Patients With Bipolar Disorder at Amanuel Mental Specialized Hospital, Addis Ababa, Ethiopia.

This study assessed the clinical response and adverse effects of lithium in patients with bipolar disorder (BD) at Amanuel Mental Specialized Hospital (AMSH) in Addis Ababa, Ethiopia. A retrospective cohort and cross-sectional design were employed as part of the Neuropsychiatric Genetics of African Populations (NeuroGAP)-Psychosis, Ethiopia project including 262 patients on lithium therapy for at least 6 months; adverse effects were evaluated in 157 of them. Clinical response was measured using the Alda scale, and adverse effects were assessed via a structured questionnaire. Among the participants, 27.5% were classified as good responders (GRs), whereas the remaining 72.5% were classified as insufficient responders (IRs), comprising both partial and nonresponders. Significant differences were observed in age group, length of lithium therapy, concomitant therapy, and number of concomitant medications, with 33% of the IRs on lithium for 1-2 years compared to only 10% of the GRs; most patients in both groups had been on lithium for 2-5 years. Additionally, 83.2% of the IRs used other medications alongside lithium, with 78% using just one additional medication. Logistic regression found that age (p = 0.008), concurrent use of other psychiatric medications (p < 0.001), and stable lithium plasma levels (p = 0.003) were significantly associated with lithium response. Regarding adverse effects, 58.6% of patients reported at least one adverse event, with tremors, excessive thirst, and frequent urination being the most common. Age, tobacco use, and treatment duration were associated with lithium adverse effects, with younger age and tobacco use linked to higher risk, whereas older age and longer treatment were associated with fewer adverse effects. In conclusion, the findings highlight the importance of monitoring use of psychiatric concomitant medications and plasma lithium levels to improve outcomes in BD patients on lithium.