Differences in Defense Mechanisms and Psychological Characteristics According to Suicide Attempt in Patients with Depression

Abstract

Objectives:The objective of the present study was to identify the differences between the defense mechanisms and psychological characteristics implemented by patients who have attempted suicide, and those implemented by depressed patients who have not. Methods: We recruited 250 depressed patients (67 with a history of one or more suicide attempts, and 183 patients without any history of suicide attempts) identified based on diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders-IV-text revision. We compared the clinical and psychological characteristics of the two groups using the Symptom Checklist-90-Revised (SCL-90-R), the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), the Personality Disorder Questionnaire-4+ (PDQ-4+), and the Defense Style Questionnaire (DSQ). Results: The patients who had a history of suicide attempt(s) recorded higher scores in all subscales of the SCL-90-R (except phobic anxiety), as well as the Infrequency (F), Back Infrequency [F(B)], Hypochondriasis (Hs), Depression (D), Psychopathic deviate (Pd), Paranoia (Pa), Psychasthenia (Pt), Schizophrenia (Sc), Hypomania (Ma) scales of the MMPI than those patients with no history of attempted suicide. The patients with no history of suicide attempt(s) recorded higher scores on the Correction (K), Superlative self-presentation (S) scales of the MMPI than those who had attempted suicide. The incidence of paranoid, schizotypal, avoidant, dependent, depressive and negativistic personality disorders (as assessed by the PDQ criteria) was elevated in those patients with histories of suicide attempt(s). Maladaptive and image-distorting defense style, as assessed by the DSQ, and acting out and affiliation were also greater in those with histories of suicide attempt(s). Conclusion: It appears that depressed patients who attempt suicide experience more clinical symptoms, use primitive defense mechanisms and, apparently, have some predictably characteristic problems. Thus, these findings might be useful to those in clinical practice, for the purpose of evaluating depressed patients at high risk for attempted suicide, versus clinically depressed patients who are not.