Empirically derived subgroups of self-injurious thoughts and behaviour: Application of latent class analysis

Latent class analysis was applied to the data to identify homogenous subtypes or classes of self-injurious thoughts and behaviour (SITB) based on indicators indexing suicide ideation, suicide gesture, suicide attempt, thoughts of nonsuicidal self-injury (NSSI), and NSSI behaviour. Analyses were based on a sample of 1,809 healthy adults. Associations between the emergent latent classes and demographic, psychological, and clinical characteristics were assessed. Two clinically relevant subtypes were identified, in addition to a class who reported few SITBs. The classes were labelled: ‘low SITBs’ (25.8%), ‘NSSI and ideation’ (25%), and ‘suicidal behaviour’ (29.2%). Several unique differences between the latent classes and external measures emerged. For instance, those belonging to the ‘NSSI and ideation’ class compared with the ‘suicidal behaviour’ class reported lower levels of entrapment, burdensomeness, fearlessness about death, exposure to the attempted suicide or self-injury of family members and close friends, and higher levels of goal disengagement and acute agitation. SITBs are best explained by three homogenous subgroups that display quantitative and qualitative differences. Profiling the behavioural and cognitive components of suicidal and non-suicidal self-injury is potentially useful as a first step in developing tailored intervention and treatment programmes.