Efficacy, effectiveness, and safety/tolerability of lithium in children and adolescents up to 18 years of age with conditions other than mood disorders: A scoping review.

In youth, lithium is an effective medication for mood disorders, particularly for mixed and manic episodes of bipolar disorder, and is generally well-tolerated. In some clinical contexts, lithium is used off-label to manage other conditions. We conducted a scoping review of studies on the efficacy/effectiveness and safety/tolerability of lithium for treating youths with psychiatric conditions other than mood disorders or neurological disorders. We searched EMBASE, MEDLINE, PsycINFO, PubMed, and ClinicalTrials.gov up to March 31, 2025, with no restrictions on language or document type. We included studies of any design involving children and adolescents (mean age up to 18) treated with lithium, either as monotherapy or in combination with other psychotropic agents. We assessed study quality using the appropriate NHLBI tools and visually summarized the results with a heat map displaying sample size by study design and conditions, as well as the timeline of included studies' publication years. From 2687 records initially identified, after de-duplication removal and screening, 367 full-text reports were assessed, and 41 studies were included in the review, grouped by type of psychiatric or neurological disorder, most of which had a small sample. Among the assessed studies, 60 % of were considered of "fair" quality and 40 % of "poor" quality. Overall, although the clinical use of lithium beyond bipolar disorder in youth is increasing, the underlying evidence base remains limited. More rigorous research based on RCTs and observational studies with designs aimed at reducing confounding are needed to guide clinical practice.