Background: Lithium remains the gold-standard medication for acute and prophylactic treatment of bipolar disorder. Understanding clinicians' practices and patients' experiences, knowledge and attitudes about lithium may improve its clinical use.

Methods: Online anonymous surveys collected information about clinician's practices and level of confidence in managing lithium and patients' experiences with lithium treatment and information received about benefits and side effects. Knowledge and attitudes regarding lithium were assessed with the Lithium Knowledge Test (LKT) and the Lithium Attitudes Questionnaire (LAQ).

Results: Among 201 clinicians, 64.2% endorsed often treating patients with lithium and reported high levels of confidence in assessing and managing lithium. Practices concerning clinical indications, drug titration, and serum levels were guideline-concordant, but compliance with monitoring recommendations was less frequent. Practitioners were interested in receiving more education about lithium. The patients' survey recruited 219 participants with 70.3% being current lithium users. Most patients (68%) found lithium helpful and 71% reported experiencing any kind of side effect. Most responders did not receive information about side effects or other benefits of lithium. Patients with higher scores on the LKT were more likely to have positive attitudes about lithium.

Limitations: Cross-sectional design with predominantly English-speaking participants from Brazil and North America.

Conclusions: There is a discrepancy between guidelines, clinician confidence and knowledge of lithium use and practice. A deeper understanding of how to monitor, prevent and manage long-term side effects and which patients are most likely to benefit from lithium may narrow the gap between knowledge and use.

Keywords: Lithium; Mood disorders; Patient-centered outcomes; Survey.