Controllability of Suicidal Thoughts Scale (CoST)

Abstract

The Controllability of Suicidal Thoughts Scale (CoST) is a brief, 10-item self-report measure developed in 2023 by Meddaoui, Iddiols, and Kaufman. Its primary purpose is to evaluate an individual’s perceived capacity for cognitive control and management over their Suicidal Thoughts. The scale development process emphasized strong face Validity, drawing heavily upon existing empirical and theoretical models concerning suicidality, coping mechanisms, and the crucial concept of personal control, referencing foundational work such as that by Batterham et al. (2015).

The CoST was validated using online samples comprising adult residents from both Canadian and American populations. Comprehensive psychometric testing included rigorous Factor Analysis, Reliability assessments, and various validity tests. This instrument is clinically significant as it provides a quantifiable measure of a person’s perceived ability to manage suicidal cognition, which is crucial for determining immediate and long-term risk levels and informing targeted psychological interventions.

Keywords

Suicidal Ideation, Perceived Control, Suicide Risk Assessment, General Control, Changing Thought Content, Incremental Validity, Psychological Assessment.

Authors

Meddaoui, Brianna, Iddiols, Bianca C., Kaufman, Erin A.

Purpose

The fundamental purpose of the CoST questionnaire is to precisely measure a person’s subjective sense of control over their Suicidal Thoughts. This psychological dimension of perceived control is considered highly important for clinical assessment and for accurately understanding an individual’s overall suicide risk level.

By assessing whether an individual feels capable of pushing away, steering, or changing the content of their suicidal cognitions, the CoST offers a unique insight into cognitive resilience. Higher scores on the scale suggest greater perceived coping resources, which may act as a protective factor against severe suicidal ideation and behavior.

Construct

The CoST measures the psychological construct of perceived control specifically as it relates to Suicidal Thoughts. This construct is delineated into two primary subscales: General Control and Changing Thought Content. General Control encapsulates the global sense of mastery or powerlessness an individual experiences regarding the occurrence, intensity, and duration of suicidal thoughts.

The second subscale, Changing Thought Content, addresses the perceived self-efficacy in actively modifying or reframing suicidal ideation, or the ability to shift attentional focus away from these intrusive thoughts. This two-factor structure provides a nuanced framework for understanding cognitive coping mechanisms in the context of suicidality.

Validity

The CoST demonstrated strong psychometric Validity across several dimensions during its initial validation study.

Convergent and Discriminant Validity: The scale established its specificity by showing that correlation coefficients between CoST scores and general constructs of coping and non-specific control were weaker compared to correlations observed with constructs directly related to suicide. This differentiation suggests the CoST measures a distinct, suicide-specific form of cognitive control.

Concurrent and Predictive Validity: The CoST proved to be an effective predictor of suicidal ideation (SI) severity both immediately and over time. Higher total scores significantly predicted a decrease in SI severity at baseline (β = −0.52, SE = 0.14, p < .001) and maintained this prospective effect one month later (β = −0.44, SE = 0.18, p < .001). Furthermore, the individual Control and Change subscales independently predicted SI severity (i.e., β = −0.38 and β = −0.44, respectively, p < .00).

Incremental Validity: Crucially for clinical utility, CoST total scores provided significant Incremental Validity in predicting a substantial portion of the variability in SI severity. This predictive contribution remained significant even after accounting for established psychological risk factors such as hopelessness (f² = .12), self-efficacy related to avoiding suicidal action (f² = .05), and general suicide-related coping (f² = .07).

Reliability

The CoST demonstrated excellent internal consistency and robust temporal stability, confirming its Reliability as a measurement tool.

Internal Consistency: The scale exhibited high internal consistency, indicated by an omega (ω) coefficient of .92. This value confirms that the items within the CoST measure a singular, coherent psychological construct effectively.

Test-Retest Reliability: The stability of the CoST over time was strong across the board. The full scale yielded a test–retest correlation of r = 0.86, while the General Control factor (r = 0.83) and the Changing Thought Content factor (r = 0.83) demonstrated similarly strong correlations, indicating that scores are stable over short periods.

Factor Analysis

The scale’s underlying structure was investigated using a combination of exploratory and confirmatory Factor Analysis techniques, ultimately supporting a parsimonious two-factor model.

Exploratory Factor Analysis: Initial data analysis, utilizing a scree plot and parallel analysis, suggested the potential existence of five factors with eigenvalues greater than 1. However, solutions featuring more than two factors proved statistically unstable, accounting for minimal variance (3%–4%) and containing items with problematic weak loadings or cross-loadings, a situation cautioned against by Costello & Osborne (2005). Therefore, the two-factor solution was deemed the most appropriate and parsimonious fit, explaining approximately 48% of the total variance.

Confirmatory Factor Analysis: The tested two-factor structure model showed a good fit to the collected data based on several standard indices (CFI = 0.94, TLI = 0.92, SRMR = 0.05). Additionally, the model demonstrated an adequate fit according to the RMSEA index (0.07, 90% CI [0.05, 0.09]), providing further structural support for the scale’s design.

Instrument

Test Type: Original Inventory/Questionnaire

Format: The CoST is a 10-item questionnaire scored on a 7-point Likert scale, ranging from 1 (strongly disagree) to 7 (strongly agree). Certain items are reverse-scored to mitigate response bias. Scores are summed to generate a total score, with higher scores indicating a greater perceived sense of control over suicidal thoughts.

Language Available: English

Population Group: Human; Male; Female

Age Group: Adulthood (18 years & older)

Population Details: Respondents were adult residents recruited online from Canada and the United States.

Test Methodology: Test Validity (Concurrent Validity, Convergent Validity, Discriminant Validity, Predictive Validity, Incremental Validity); Test Reliability (Internal Consistency, Test-Retest Reliability); Factor Analysis (Confirmatory Factor Analysis, Exploratory Factor Analysis).

Keywords

Suicidal Ideation, Perceived Control, Cognitive Control, Mental Health Assessment, Psychological Inventory, Risk Stratification, Likert scale.

Authors

Author ORCID Identifier:

• Meddaoui, Brianna: http://orcid.org/0000-0002-8813-5844

• Kaufman, Erin A.: http://orcid.org/0000-0002-7636-6602

Affiliation Email addresses:

• Meddaoui, Brianna: University of Western Ontario, Department of Psychology

• Iddiols, Bianca C.: University of Western Ontario, Department of Psychology

• Kaufman, Erin A.: University of Western Ontario, Department of Psychology

• Meddaoui, Brianna (Email): [email protected]

Correspondence Address:

Meddaoui, Brianna: University of Western Ontario, Department of Psychology, 361 Windermere Road, London, Ontario, Canada, N6A 3K7, [email protected]

Permissions & Fee and Test Year

Permissions: May be used for Research/Teaching.

Fee: No

Commercial: No

Test Year: 2023

Reference’s

Meddaoui, B., Iddiols, B. C., & Kaufman, E. A. (2023). The Controllability of Suicidal Thoughts (CoST) Scale: Development, factor structure, and initial validation. Psychological Assessment, 35(10), 880–887. https://doi.org/10.1037/pas0001271

Items of the Controllability of Suicidal Thoughts Scale (CoST)

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

Items

The following statements pertain to thoughts about suicide. This may include thoughts such as “I don’t want to be alive anymore,” “I wish I were dead,” or “I want to kill myself.” When we say thoughts, we mean ideas you have, words you say to yourself in your head, and/or images you think about.
Typically, when I have thoughts about suicide, I…

Item Number	Statement	Strongly Disagree (1)	Disagree (2)	Somewhat Disagree (3)	Neither Agree nor Disagree (4)	Somewhat Agree (5)	Agree (6)	Strongly Agree (7)
1	Can push these thoughts away	1	2	3	4	5	6	7
2	Feel like I’m powerless over these thoughts	1	2	3	4	5	6	7
3	Feel like I can steer where these thoughts go	1	2	3	4	5	6	7
4	Cannot control these thoughts	1	2	3	4	5	6	7
5	Become stuck in these thoughts	1	2	3	4	5	6	7
6	Am able to easily shift my focus away from these thoughts	1	2	3	4	5	6	7
7	Feel like I’m in control of these thoughts	1	2	3	4	5	6	7
8	Feel like these thoughts are not changeable	1	2	3	4	5	6	7
9	Cannot change or reframe these thoughts	1	2	3	4	5	6	7
10	Feel like these thoughts will only get worse no matter what I do	1	2	3	4	5	6	7

Scoring

Scales can be summed to create a total score, ranging from 10 – 70. The six items to be reverse coded are indicated in grey. Higher total and subscale scores reflect better perceived control over one’s suicidal thoughts.

Subscales

General Control

1. When I’m upset, I believe that I will end up feeling very depressed.

2. When I’m upset, I believe there is nothing I can do to make myself feel better.

3. When I’m upset, it takes me a long time to feel better.

4. Cannot control these thoughts

5. Become stuck in these thoughts

6. Am able to easily shift my focus away from these thoughts

7. Feel like I’m in control of these thoughts

Changing Thought Content

1. When I’m upset, I become embarrassed for feeling that way.

2. When I’m upset, I feel guilty for feeling that way.

3. When I’m upset, I become irritated at myself for feeling that way.