Risk of Suicide Related to Mental Disorders in Catalonia, Spain: A Population Registry-Based Cohort Study

Introduction Registry-based studies are efficient to investigate population mental health and suicide risk, but are largely absent in Europe outside of Scandinavia and the UK. Objectives To investigate suicide risk associated with mental disorders in the Catalan population (7.6 million), stratified by gender and history of psychiatric hospitalization. Methods Population-representative retrospective registry-based cohort study including 764,938 Catalan residents in the period 2014-2019. Data sources included suicide mortality, electronic health registries from five healthcare settings, and administrative data. Suicide deaths were identified through judicial death registers using ICD-10 codes X60-X84. ICD-9CM and ICD10CM codes from all inpatient and outpatient healthcare contacts were used to categorize 109 mental disorders. Age-sex standardized mortality ratios (SMRs) were calculated using indirect standardization, with expected deaths based on official general population mortality rates in Catalonia. Results Suicide risk was significantly elevated among Catalan residents diagnosed with any mental disorder (SMR [95%CI] = 1.6 [1.3-1.9] for females; SMR = 1.8 [1.6-2.0] for males). In females, suicide risk was highest for sedative or hypnotic abuse (SMR = 46.1 [3.7-88.5]), cocaine abuse (SMR = 42.8 [9.0-76.6]), borderline personality disorder (SMR = 33.0 [10.7-55.3]), polysubstance abuse (SMR = 32.9 [2.1-63.8]), and mental disorder not otherwise specified (SMR = 24.9 [11.7-38.1]). In males, risk was highest for obsessive-compulsive disorder (SMR = 20.2 [10.7-29.8]), acute and transient psychotic disorders (SMR = 17.9 [1.1-34.8]), mental disorder not otherwise specified (SMR = 17.2 [10.1-24.3]), paranoid schizophrenia (SMR = 16.8 [9.4-24.1]), and opioid abuse (SMR = 16.1 [1.6-30.6]). Suicide risk was substantially elevated in individuals with a history of psychiatric hospitalization (SMR = 18.3 [15.5-21.2]] for females; SMR = 13.4 [12.0-14.8] for males). In females with psychiatric hospitalization history, risk was highest for dependence on stimulants other than cocaine (SMR = 105.4 [11.6-199.3]), attention deficit hyperactivity disorder (SMR = 86.2 [19.2-153.2]), polysubstance abuse (SMR = 66.0 [33.6-98.3]), opioid abuse (SMR = 60.1 [2.1-118.1]), and cocaine abuse (SMR = 57.2 [32.6-81.8]). In males with psychiatric hospitalization history, risk was highest for obsessive-compulsive disorder (SMR = 45.7 [30.6-60.8]), schizoid personality disorder (SMR = 36.9 [13.5-60.2]), unspecified disorders of adult personality and behaviour (SMR = 35.0 [9.6-60.3]), schizotypal disorder (SMR = 34.3 [6.7-61.9]), and histrionic personality disorder (SMR = 32.5 [1.2-63.9]). Conclusions Risk of suicide in the Catalan population varies substantially by mental disorder type, gender, and psychiatric hospitalization history, highlighting the need for targeted and diversified prevention strategies. Disclosure of Interest P. Mortier Grant / Research support from: Miguel Servet CP21/00078 (ISCIII co-funded by the ESF+); project 202220-30-31 (Fundació la Marató de TV3); PI22/00107 (ISCIII, cofunded by the European Union); AC22/00006 (ISCIII and the European Union NextGenerationEU, Mecanismo Para la Recuperación y la Resiliencia), L. Latorre-Moreno: None Declared, F. Amigo: None Declared, M. López: None Declared, A. Portillo-Van Diest Grant / Research support from: PFIS FI23/00004 (ISCIII co-funded by the ESF+), L. Ballester: None Declared, J. Alonso Grant / Research support from: AGAUR 2021 SGR 00624; CB06/02/0046 (CIBERESP - ISCIII), G. Vilagut: None Declared