Objective: This study (i) explores differences between a clinical sample of deliberate self-poisoning (DSP) patients and a community sample who reported previous attempted suicide (AS); and (ii) examines correlates of suicidal behaviour in these groups compared with a community control group (CC) with no suicidal behaviour.
Method: The study design was: case-case, case-control and cross-sectional population studies. A clinical sample of DSP (n = 51), a community sample of AS (n = 31) and a community sample with no suicidal behaviour (n = 842) were used, all aged 18-24 years. The DSP and AS groups were compared on several variables and two logistic regression models were developed for risk of (i) DSP and (ii) AS compared to community controls.
Results: The adjusted odds ratios for DSP were: female gender (OR = 5.7, CI = 1.7-19.4), anxiety (OR = 7.4, CI = 2.2-25.1), affective (OR = 23.0, CI = 6.9-76.5), or substance-use disorder (OR = 19.2, CI = 5.6-65.4) and greater mental health related disability (OR = 0.5, CI = 0.3-0.7 for 1 SD decrease). For AS the results were: anxiety (OR = 9.4, CI = 1.7-52.8) or substance-use disorder (OR = 3.0, CI = 1.1-8.7) and greater mental health disability (OR = 0.5, CI = 0.4-0.7). Affective disorder was close to significant for the AS group (OR = 4.0, CI = 0.9-17.1).
Conclusions: Correlates of DSP/AS were usually more powerful in the clinical group, but showed a similar pattern of psychiatric disorder and disability factors in both groups, supporting a continuum of risk factors across these groups. Interventions based on modifiable risk factors could target the same factors for public health, primary care or hospital populations: anxiety, depression and substance use disorders and mental health related disability.