Enhanced Brief CBT for Suicidal Inpatients With Mood Disorders

The number of suicide attempts will be assessed at five time points (baseline, post-treatment, and monthly during the 3-month follow-up) using the Columbia-Suicide Severity Rating Scale, with data cross-checked against electronic medical records.

The number of days from hospital discharge to the first reported suicide attempt, assessed through monthly follow-up interviews during the 3-month follow-up period.

Suicidal ideation intensity will be assessed using the Intensity of Ideation subscale of the C-SSRS. This clinician-administered interview includes five items (frequency, duration, controllability, deterrents, and reasons for ideation), each scored from 0 to 5. Higher scores indicate greater ideation intensity.

Suicidal ideation severity will be assessed using the Beck Scale for Suicide Ideation, a 19-item self-report questionnaire. Each item is scored from 0 to 2, producing a total score from 0 to 38. Higher scores indicate greater severity of suicidal ideation.

Depressive symptom severity will be assessed at five time points using the 17-item Hamilton Depression Rating Scale. This clinician-administered semi-structured interview yields total scores ranging from 0 to 52, with higher scores indicating more severe depression.

Depressive symptom severity will be assessed at five time points using the Beck Depression Inventory-II, a 21-item self-report questionnaire. Each item is scored from 0 to 3, yielding total scores from 0 to 63. Higher scores indicate greater symptom severity.

Change in the level of hopelessness will be assessed at five time points: baseline, post-treatment, and monthly for 3 months following discharge. Hopelessness will be measured using the Beck Hopelessness Scale (BHS), a 20-item self-report questionnaire designed to assess negative expectations about the future. Each item is scored dichotomously (True/False), with total scores ranging from 0 to 20. Higher scores indicate greater levels of hopelessness and have been associated with increased suicide risk.

Consent rate will be used as a key feasibility indicator. It is defined as the percentage of eligible participants who provided informed consent and were randomized. The rate will be calculated by dividing the number of participants who consented and were randomized by the total number of eligible participants screened during the recruitment period.

Retention rate will be used as a key feasibility indicator. It is defined as the percentage of randomized participants who remained in the study and provided valid primary outcome data at each designated follow-up time point. The rate will be calculated by dividing the number of participants who completed the primary outcome assessment at each time point by the total number of participants randomized.

Adherence to treatment will be used as a feasibility indicator. It is defined as the percentage of participants who attended all 5 scheduled treatment sessions. The rate will be calculated by dividing the number of participants who completed all sessions by the total number of participants assigned to the intervention group.

Implicit identification with death will be assessed using the Death-Implicit Association Test (D-IAT), a computerized task measuring automatic associations between death-related concepts and the self. The Korean version of the D-IAT, validated for local use, consists of seven blocks administered via PsychoPy software. The outcome score (D-score) is computed using a standard scoring algorithm: a positive D-score indicates a stronger implicit association between death and self, while a negative score indicates a stronger association between life and self. Higher D-scores have been associated with increased risk of suicide attempts.

Anxiety symptoms will be assessed at all scheduled time points using the Beck Anxiety Inventory (BAI), a 21-item self-report questionnaire. Each item is rated on a 0 to 3 scale, yielding a total score from 0 to 63. Higher scores indicate greater anxiety severity.

Emotion dysregulation will be assessed at all scheduled time points using the 35-item Korean version of the Difficulties in Emotion Regulation Scale (DERS). This self-report questionnaire measures six dimensions of emotion regulation difficulties: Nonacceptance of emotional responses, Difficulties engaging in goal-directed behavior, Impulse control difficulties, Lack of emotional awareness, Limited access to emotion regulation strategies, and Lack of emotional clarity. Each item is rated on a 5-point Likert scale from 1 to 5, with higher scores indicating greater difficulties in emotion regulation.

Distress tolerance will be assessed at all scheduled time points using the Distress Intolerance Index (DII), a 10-item self-report questionnaire. Each item is rated on a 5-point Likert scale from 0 (not at all like me) to 4 (very much like me), with total scores ranging from 0 to 40. Higher scores indicate lower distress tolerance.

Negative automatic thoughts will be assessed using the Automatic Thoughts Questionnaire-Negative (ATQ-N), a 30-item self-report measure. Participants rate how frequently they experienced each thought on a 5-point Likert scale from 1 (not at all) to 5 (all the time). Total scores range from 30 to 150, with higher scores indicating greater frequency of negative automatic thoughts.

Positive automatic thoughts will be assessed using the Automatic Thoughts Questionnaire-Positive (ATQ-P), a 30-item self-report measure. Each item is rated on a 5-point Likert scale from 1 (not at all) to 5 (all the time). Total scores range from 30 to 150, with higher scores indicating more frequent positive automatic thoughts.

Interpersonal needs will be assessed using the Interpersonal Needs Questionnaire (INQ), a 15-item self-report measure designed to assess two constructs: perceived burdensomeness and thwarted belongingness. Each item is rated on a 7-point Likert scale from 1 (not at all true for me) to 7 (very true for me). Higher scores reflect greater interpersonal distress.

Fearlessness about death will be assessed using the Acquired Capability for Suicide Scale - Fearlessness About Death (ACSS-FAD), a 7-item self-report questionnaire. Each item is rated on a 5-point Likert scale from 0 (not at all like me) to 4 (very much like me), with higher scores indicating greater fearlessness about death.

Treatment satisfaction will be assessed using the Client Satisfaction Questionnaire (CSQ-8), an 8-item self-report instrument rated on a 4-point Likert scale. The measure assesses satisfaction with treatment quality, perceived effectiveness, and willingness to reuse or recommend the intervention. Higher total scores indicate greater satisfaction.

The Utility of Techniques (UT) questionnaire will be used to assess participants' frequency of use and perceived helpfulness of specific intervention components. For each technique the participant reports having learned during the inpatient stay, they will rate frequency of use (from "not at all" to "more than 10 times per week") and helpfulness (if used, from "not at all" to "extremely"). Techniques include, for example, personalized safety planning tools and coping strategies taught during the intervention.