A longitudinal study of suicidal ideation among homeless, mentally ill individuals

Previous cross-sectional studies have indicated that homeless individuals may present with high rates of suicidal ideation, which are strongly associated with completed suicide. We conducted the first known longitudinal study of suicidal ideation in the homeless.

We used data collected over 24 months in the Vancouver At Home project (N = 497), comprised two randomized-controlled trials of housing interventions for homeless individuals with mental disorders. Presence of suicidal ideation was determined using the Colorado symptom index.

Suicidal ideation significantly decreased over time [odds ratio (OR) = 0.31 at 24 months, 95 % confidence interval (CI) 0.21-0.46]. Baseline diagnoses of mood (OR = 2.18, 95 % CI 1.48-3.21) and anxiety disorders (OR = 2.05, 95 % CI 1.42-2.97), as well as depressive mood (OR = 2.52, 95 % CI 1.90-3.33), use of any substance (OR = 1.59, 95 % CI 1.09-2.32), and polysubstance use (OR = 1.90, 95 % CI 1.40-2.60) were significantly associated with suicidal ideation in the multivariate model. Baseline diagnosis of a psychotic disorder (protective effect), daily substance use, intravenous drug use, recent arrest, multiple physical illnesses and history of traumatic brain injury were significantly associated with suicidal ideation in the unadjusted model only.

Interventions targeting depressive symptoms and substance use could help decrease suicide risk in homeless individuals. Mental health services need to be tailored to address the complex needs of socially marginalized individuals.

Current controlled trials: ISRCTN57595077 (Vancouver At Home study: Housing First plus Assertive Community Treatment versus congregate housing plus supports versus treatment as usual) and ISRCTN66721740 (Vancouver At Home study: Housing first plus intensive case management versus treatment as usual). Assigned 9 Oct. 2012.