Mental Disorders and Psychological Autopsies in Global Suicide Pacts: A Systematic Review of Case-based Evidence

Background: Suicide pact, although rare, represents a unique phenomenon of self-inflicted simultaneous deaths among individuals influenced by psychological, social, and cultural factors. Understanding the underlying motivations and mental health conditions of individuals involved in such pacts is crucial for effective prevention strategies. The purpose of this review is to estimate the global data on mental disorders associated with suicide pacts, synthesize various definitions of suicide pacts in the literature, and report associated toxicological findings. Methods: A systematic literature search was conducted till March 17, 2025, across Cochrane, PubMed, ScienceDirect, and Scopus, and the review was registered with the PROSPERO database (Registration No: CRD420251120587). Results: The review included 14 studies with asphyxia as the most common method employed during a suicide pact, suggesting carbon monoxide poisoning. Depression, personality disorder, shared psychotic disorder, and substance abuse were common mental morbidities described in the literature, along with chronic physical illness as a risk factor. Toxicology analyses confirmed alcohol, opioids, and benzodiazepines among substance intoxication. Victim relationships reflected romantic partners and spouses being most commonly involved. Motivations ranged from social isolation and financial distress to familial opposition to intercaste relationships. Conclusion: The review shows that suicide pacts often involve rapid, painless methods, include farewell notes and are associated with mental disorders. Overall, the lack of robust psychological autopsy and mostly case-based evidence favors the association of mental illness, although the actual rate of underlying psychiatric disorders needs further study. Public health narratives should abstain from glorifying ‘dying together,’ and prevention efforts must engage community gatekeepers. PROSPERO Registration: CRD420251120587.