Identifying subgroups within a sample of adults with a suicide attempt history using the Interpersonal Psychological Theory of Suicide

This study used a novel theory-informed latent class approach, based on the Interpersonal Psychological Theory of Suicide (IPTS), to identify subgroups of individuals with a suicide attempt history. The identification of subgroups can inform treatments that target these specific subgroups. Using data from a randomised controlled trial, latent class analysis was conducted on 227 adults with a suicide attempt history. Latent classes were identified based on suicide attempt history, perceived burdensomeness, thwarted belongingness, and capability for suicide at the trial baseline. Three classes were found. Classes 1 and 2 (80% of participants) at baseline had higher interpersonal risks and clinical symptoms, and lower protective psychological factors (e.g., positive reframing), compared to Class 3 (20% of participants). Class 1 had elevated suicidal ideation for the duration of the trial. Classes 1 and 2 also had elevated interpersonal risks relative to a population-based sample. These results suggest that some individuals with a suicide attempt history exhibit relatively low interpersonal risks, and given concurrent protective psychological factors, may be suited to low-intensity interventions. At the other extreme, some individuals with a suicide attempt history require high-intensity interventions addressing interpersonal risks, clinical symptoms, and protective psychological factors.