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Keywords:

  • depressive disorder;
  • problem drinking;
  • suicide risk

Abstract

  1. Top of page
  2. Abstract
  3. METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES

The present study sought to determine whether the co-occurrence of problem drinking heightens suicide risk in individuals with depression in Japan, using a sample of 784 outpatients (287 men and 497 women) with depressive disorder. Female subjects with at least a moderate problem drinking showed significantly more severe depression and suicidality than those without, but no such difference was identified in men.

A PREVIOUS STUDY has indicated that the co-occurrence of alcohol abuse/dependence heightens suicide risk in individuals with depression1 because excessive drinking may worsen psychiatric problems, negatively impact psychosocial situations, and increase impulsive behavior.2 In spite of this, clinicians are likely to overlook or underestimate the significance of co-occurring alcohol abuse/dependence and depression in patients. All suicide-completers in our previous psychological autopsy study, who were under psychiatric treatment at the time of death and were considered to have co-occurring depression and alcohol-related problems, were receiving pharmacotherapy targeting depressive disorder only; alcohol abuse/dependence went untreated.3 The purpose of the present study was to examine whether the co-occurrence of problem drinking heightens suicide risk in individuals with depression in Japan.

METHODS

  1. Top of page
  2. Abstract
  3. METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES

Subjects

Our patient pool comprised 963 consecutive outpatients with a DSM-IV-TR diagnosis of depressive disorder (major depressive disorder, dysthymic disorder, and depressive disorder not otherwise specified), who visited one of five general psychiatric clinics during December 2009. Psychiatrists at these five clinics recommended study participation to all outpatients who met the DSM-IV-TR criteria for depressive disorder. A total of 917 patients (95.2%) consented to participate. After data-deficit samples were excluded from the 917 patients, 784 (81.4%; 287 men and 497 women; mean age ± SD, 43.8 ± 13.6 years) remained as subjects.

This study was approved by the ethics committee of the National Center of Neurology and Psychiatry.

Procedures

Self-reported information on the severity of each patient's alcohol-related problems, depression, and suicide risk was collected cross-sectionally via a questionnaire consisting of three scales: the Alcohol Use Disorders Identification Test (AUDIT), the Kessler 10 (K10), and the Mini International Neuropsychiatric Interview (M.I.N.I.).

The AUDIT, a self-report rating scale used worldwide, was developed by the World Health Organization to evaluate the severity of an individual's alcohol-related problems.4 In the original version, a score greater than 8 indicates the presence of a moderate level of problem drinking, and a score greater than 20 indicates a severe level,5 while in the Japanese version, the cut-off for a moderate level is from 10 to 14.6 In the present study, each score greater than 10 or 20 was defined as a moderate or severe level.

The K10 is a brief self-report questionnaire that screens for depressive disorder.7 This rating scale has been employed worldwide in epidemiological studies, and the validity and reliability of the Japanese version have been established.8

The M.I.N.I. is a structured interview schedule that screens for various psychiatric disorders.9 The validity and reliability of the Japanese version have been confirmed.10 The scores for each answer are weighted according to their importance in assessing suicide risk, with a total score greater than 10 indicating a high risk. The six items on the Japanese M.I.N.I. associated with suicide risk were included in our self-report questionnaire. Total scores were analyzed after the internal consistency of these items was established for our sample (Cronbach's α = 0.755).

Statistical analysis

Based on their AUDIT scores, subjects were divided into three groups: the non-problem-drinking (NPD) group (scores ≤9), the moderate problem-drinking (MPD) group (scores 10–19), and the severe problem-drinking (SPD) group (scores ≥20). Consequently, the subjects were divided into the three groups as follows: 638 (81.4%) in the NPD group, 97 (12.4%) in the MPD group, and 49 (6.3%) in the SPD group.

We then performed an anova to compare suicidality as assessed by the K10 and M.I.N.I. portions of the questionnaire across the three groups for each sex. When the anova revealed a significant difference, a Bonferroni post hoc test was performed to explore the difference. The level of significance was set at P < 0.05, and all P-values were two-tailed.

RESULTS

  1. Top of page
  2. Abstract
  3. METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES

An examination of group distribution in each sex revealed that a significantly greater proportion of men exhibited problem drinking (MPD and SPD) compared to women (23.3% [67/287] vs 15.9% [79/497], respectively; see Table 1).

Table 1.  Comparison of K10 and M.I.N.I. suicide risk scores in non-problem, moderate, and severe problem drinking groups by sex Thumbnail image of

Table 1 compares scores on the K10 and M.I.N.I. suicide risk items across the groups for each sex. Although among men the three groups exhibited no significant differences in the K10 or M.I.N.I. suicide risk scores, among women the groups exhibited significant differences in both scores. Bonferroni post hoc tests demonstrated that the female MPD and SPD groups scored significantly higher on the K10 and M.I.N.I. suicide risk questions than the female NPD group. No such significant difference was observed between the female MPD and SPD groups.

DISCUSSION

  1. Top of page
  2. Abstract
  3. METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES

Consistent with findings in previous studies,1 male patients exhibited co-occurring depressive disorder and problem drinking more frequently than women. We observed a significant association between problem drinking and suicidality among women, however, not among men. This suggests that problem drinking may elevate the suicide risk of female patients with depressive disorder. To our knowledge, no previous studies on the co-occurrence of depression and alcohol-related disorders have addressed this sex difference, although our previous study indicated that female substance abusers were more likely to exhibit depression and suicidality than men.11

The present study also demonstrated that, in female subjects with problem drinking, the severity of problem drinking was not associated with either severity of depression or suicide risk. This finding is supported by De Leo and Evans,2 who reported that excessive drinking may be directly instrumental in the act of suicide by increasing impulsive behavior, even if problem-drinking episodes occur only occasionally and/or do not constitute alcohol dependence. Additionally, it has been speculated that some depressive women may drink heavily with a self-destructive intent. It is therefore particularly important for clinicians to pay attention to the drinking behavior of female depressed patients.

This study has several limitations. First, the presence of a sampling bias cannot be excluded because subjects were from only five psychiatric clinics. Accordingly, the generalizability of our findings is limited. Second, the data were self-reported, acquired via questionnaires rather than through structured interviews. Third, life background, including status of cohabitation and family relationships, was not considered. Lastly, comorbid psychiatric disorders other than alcohol use disorder, including borderline personality disorder, were not considered. Despite these limitations, this study is important as the first to reveal that the co-occurrence of problem drinking may increase suicide risk among female patients with depressive disorder.

REFERENCES

  1. Top of page
  2. Abstract
  3. METHODS
  4. RESULTS
  5. DISCUSSION
  6. REFERENCES
  • 1
    Davis LL, Rush JA, Wisniewski SR et al. Substance use disorder comorbidity in major depressive disorder: an exploratory analysis of the Sequenced Treatment Alternatives to Relieve Depression cohort. Compr. Psychiatry 2005; 46: 8189.
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    De Leo D, Evans R. The impact of substance abuse policies on suicide mortality. In : De Leo D, Evans R (ed.). International Suicide Rates and Prevention Strategies. Hogrefe & Huber, Cambridge, 2004; 101112.
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    Akazawa M, Matsumoto T, Katsumata Y et al. Psychosocial features of suicide completers with alcohol problem: a psychological autopsy study. Jpn Alcohol. Drug Depend. 2010; 45: 104118. (in Japanese).
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    Sheehan DV, Lecrubier Y, Sheehan KH et al. The Mini International Neuropsychiatric Interview (M.I.N.I.): the development and validation of a structured diagnostic psychiatric interview for DSM-IV and ICD-10. J. Clin. Psychiatry 1998; 59: 2233.
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