As a psychiatry trainee you will never forget that the two medications that reduce suicide are lithium and clozapine. In the case of clozapine, it has been shown in RCTs to reduce suicidal thoughts but not necessarily completed suicides. Lithium on the other hand has RCT data that indicates it reduces suicidal thoughts as well as completed suicide.

Lithium has anti-suicidal effects even at low doses. Lithium’s anti-suicidal effects are beneficial for both unipolar and bipolar depression. Unlike standard antidepressants that can increase the risk of suicide specifically in younger patients under the age 24, lithium has a prophylactic effect to prevent suicide. 

While lithium overdoses can be fatal, this outcome is less likely given the anti-suicidal properties of this medication. We should not avoid prescribing it for this reason.