Lithium and clozapine are the only two somatic treatments with high-quality evidence of reducing suicide risk, in mood disorders and schizophrenia respectively; stopping lithium increases that risk. Ketamine and esketamine may offer a small, immediate antisuicide effect, though a disproportionate number of suicides occurred in esketamine-treated subjects versus placebo (3 vs. 0 among over 3500 subjects), requiring ongoing evaluation. The evidence for electroconvulsive therapy's antisuicide effect is low-quality. Antidepressants' effect is unclear: direct evidence shows they may increase suicidal ideation and risk in young people over the short term, while indirect evidence suggests they reduce risk over the long term. Clinicians have an expanding pharmacopeia, but some agents may also increase suicidality under specific circumstances.
Three cases from a dual diagnosis inpatient psychiatry unit in 2023 illustrate distinct adverse effects of psilocybin use. Intermittent use led to prolonged psychosis requiring higher and longer neuroleptic treatment; frequent short-term use culminated in paranoia and a serious suicide attempt treated with neuroleptics; long-term microdosing preceded mania-like symptoms—grandiosity, irritability, physical aggression—that resolved after stopping psilocybin. As psilocybin becomes more accepted and prevalent, clinicians lack guidelines for managing its complications. This case series describes varied presentations, management strategies, and treatment responses to provide insight into this unknown territory.