Firesetting among People with Mental Disorders: Differences in Diagnosis, Motives and Behaviour

Abstract Despite the prevalence of mental disorder among firesetters, there is limited empirical research on how firesetting manifests in people with different psychiatric conditions. In this study, classification methodology was used to explore different types of firesetting committed by people with mental disorders. Associations between motives, diagnoses, situational, and behavioral variables were also observed to clarify the nexus between mental disorder and firesetting. A sample of 103 mentally disordered firesetters referred to community-based forensic mental health services was used. Four types of firesetting perpetrated by people with mental disorders were differentiated using multidimensional scaling: (1) Psychotic Struggle, (2) Hopeless, (3) Dysregulated, and (4) Fire Interest. In the first two types of firesetting, motives of revenge and suicide were mainly derived from psychotic symptoms and a more direct relationship between psychosis and firesetting was observed. Conversely, the latter two types featured motives of express frustration and excitement seeking, in association with personality disorder and pyromania, respectively. These types indicated pathways to firesetting wherein the corresponding mental disorder appeared to exacerbate predisposing vulnerabilities for firesetting. The implications for clinical formulation and theory development are discussed, emphasizing the need to better understand the etiology of firesetting including the underlying motives, psychopathology and context.