The Controllability of Suicidal Thoughts (CoST) Scale: Development, factor structure, and initial validation.

Suicidal ideation (SI) is common, harmful, and distressing. Prior research suggests a person's sense of perceived control over their suicidal thoughts may be important for understanding risk level. However, no measurement tool currently exists to capture this experience. The present study seeks to establish a brief self-report instrument to assess the degree of perceived control an individual has over their suicidal thoughts. We conducted two studies to test the psychometric properties and factor structure of the Controllability of Suicidal Thoughts (CoST) scale. Two online convenience samples were used; participants were recruited via Prolific (Study 1; n = 244, M age = 29.19, female = 51.2%, White = 68.9%, non-Hispanic = 92.6%, heterosexual = 48.0%) and via online webpages and forums (Study 2; n = 206, Mdn age = 25-30 years, female = 56.5%, White = 55.2%, non-Hispanic = 84.4%, heterosexual = 51.3%). Exploratory factor analyses (Study 1) yielded a two-factor structure for the CoST, which was replicated in the second sample. CoST scores were associated with various constructs related to suicidality (i.e., SI severity, self-efficacy to avoid suicidal action, suicide-related coping, hopelessness), locus of control, coping, and emotion dysregulation. Results indicate the CoST has high internal consistency (ω = .92), good test-retest reliability, and preliminary evidence of predictive and construct validities. The CoST shows promise for future research applications, aids our understanding of suicide-related cognitions, and may predict important suicide-related outcomes. (PsycInfo Database Record (c) 2023 APA, all rights reserved).