The effect of stress and egocentricity on depression and aggression: mediated by the emotion regulation difficulties
Description
Measures Depression (SCL-90): Symptom Checklist-90-Revised is a 90-item self-report psychiatric symptoms index that was developed by Derogatis (1994). It is designed to evaluate symptoms of psychopathology as classified in DSM-IV. The Subscale of depression was used in this study. It is scored on a 5-point Likert scale. Several studies confirmed the validity and reliability of this test. In the present study, the Cronbach’s alpha for the depression scale was α = 0.90. BUSS & Perry Aggression Questionnaire-Short form (BPAQ-SF): This questionnaire developed by Bryant and Smith (2001). It has a four-factor structure (hostility, anger, verbal, and physical aggression). It has12-items and is scored on a 5-point Likert scale. In the study of Bryant and Smith (2001), the construct validity, discriminant validity, and Reliabilities were adequate, the alpha coefficients for the subscales were 0.84, 0.82, 0.72, and 0.78, respectively. In this study, the Cronbach’s alpha for the total score was α =0 .88. Difficulties in Emotion Regulation Scale (DERS): This questionnaire developed by Gratz and Roemer (2004). It has 33 items and, six subscales. In this study, we used a total score of three subscales of difficulty engaging in goal-directed behavior, impulse control difficulty, and limited access to emotion regulation strategies. The items on this scale scored on a five-point Likert scale (from1=almost never to 5=almost always). Gratz and Roemer (2004) found good reliability for total score (Cronbach’s α=0.93), concurrent and predictive validity for this questionnaire. In this study Cronbach’s alpha for (DERS) total score was α=0.90. Egocentricity: we used the Machiavellian Egocentricity subscale of Psychopathic Personality Inventory-Revised (PPIR). Sörman et al. (2016) developed this questionnaire to measure affective and interpersonal dispositions of psychopathy. It has 154 items and eight subscales. It is a Likert type scale (from 1 - ‘false’ to 4 - ‘true’). The Machiavellian Egocentricity scale included ten items. It is appropriate for use with both criminal and noncriminal persons. Sörman et al. (2016) demonstrated good construct validity and reliability (test-retest, internal consistency α = 0.85) in non-criminal individuals. In this study, the Cronbach’s alpha for the Machiavellian Egocentricity was α =0 .84. Depression Anxiety and Stress Scale (DASS-21): The (DASS-21) is a set of three self-report scales designed to measure the emotional states of depression, anxiety, and stress. It developed by Lovibond and Lovibond (1996). In this study, we used the stress subscale consisted of seven items. Previous studies have reported a good Cronbach's alpha coefficient of 0.95 (Anthony et al., 1998). In this study, the Cronbach’s alpha for the stress scale was α = .80.