Association between suicide-related ideations and affective temperaments in the Japanese general adult population

• Published in: PloS one Vol. 12; no. 6; p. e0179952
• Main Authors: Mitsui, Nobuyuki, Nakai, Yukiei, Inoue, Takeshi, Udo, Niki, Kitagawa, Kan, Wakatsuki, Yumi, Kameyama, Rie, Toyomaki, Atsuhito, Ito, Yoichi M, Kitaichi, Yuji, Nakagawa, Shin, Kusumi, Ichiro
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 22-06-2017; Public Library of Science (PLoS)
• Subjects: Adult; Analysis; Confidence intervals; Cross-Sectional Studies; Data processing; Emotional disorders; Female; Gender differences; Humans; Japan; Male; Medicine; Medicine and Health Sciences; Men; Mental depression; Mental health; People and Places; Personality; Physical Sciences; Prevention; Primary care; Psychiatry; Questionnaires; Risk analysis; Risk factors; Self destructive behavior; Self esteem; Studies; Suicidal behavior; Suicidal Ideation; Suicide; Suicides & suicide attempts; Surveys and Questionnaires; Temperament; University graduates; Validity; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0179952

Suicide rates are vastly higher in Japan than in many other countries, although the associations between affective temperaments and suicide-related ideations in the general adult population remain unclear. Therefore, we aimed to elucidate these associations in the present study.
We analyzed data from 638 Japanese volunteers who completed both the Patient Health Questionnaire (PHQ-9) and the Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Auto-questionnaire (TEMPS-A). Participants were then divided into three groups based on PHQ-9 summary scores and responses to the suicide-related ideation item: non-depressive control group (NC; N = 469), depressive symptoms without suicide-related ideations group (non-SI; N = 135), and depressive symptoms with suicide-related ideations group (SI; N = 34). The depressive symptoms were defined for PHQ-9 summary scores ≥5, and the suicide-related ideations were defined for PHQ-9 #9 score ≥1. We then compared TEMPS-A scores among the groups using Kruskal-Wallis tests. Then the 95% confidence intervals of differences in TEMPS-A subscale scores between the NC and non-SI groups, or between NC and SI groups, were calculated.
Participants of the SI group exhibited significantly higher scores on the depressive, irritable, and anxious temperament subscales than those of the non-SI group. Similarly, women of the SI group exhibited significantly higher scores of the depressive and irritable temperament subscales than women of the non-SI group, while men of the SI group exhibited significantly higher depressive temperament scores than those of the non-SI group. Among all participants and only men, cyclothymic subscale scores were higher in those of the SI group than the non-SI group (not significant), although the 95% confidence intervals did not overlap.
The cross-sectional study design was the main limitation.
Depressive, irritable, and anxious temperaments are significant risk factors for suicide-related ideations in the Japanese general adult population. Furthermore, irritable temperament in women and depressive temperament in men are associated with suicide-related ideations.