Predictors of suicidal thoughts: Mood instability versus neuroticism

The personality trait neuroticism predicts depression and suicidal thoughts. Neuroticism is also linked to mood instability (MI) that is common in patients with depression. This study investigated (a) whether MI predicts suicidal thoughts in depressed patients and (b) the relationship of MI to neuroticism. All 129 patients with Major Depression (MINI interview) were assessed on MI (Affective Lability Scale), neuroticism (Short Eysenck Neuroticism Scale), depression (Beck Depression Inventory), and suicidal thoughts (Beck Scale for Suicidal Ideation). Participants also completed the Perceived Stress Scale, Mood Disorder Questionnaire and five clinical questions on MI. Factor analysis of the Eysenck Neuroticism Scale revealed unstable moods as one of three main factors. Only depression severity and MI predicted suicidal thoughts once other variables including neuroticism were controlled. Mediation analyses showed that MI mediated the relationship between neuroticism and suicidal thoughts. These results suggest that MI as measured by the Affective Lability Scale typifies the type of depression that predicts suicidal thoughts and that MI may be more directly associated with suicidal thoughts than neuroticism. This demonstrates the clinical value of assessing MI rather than neuroticism in the treatment of patients with depression with suicidal thoughts. 2011 Elsevier Ltd. All rights reserved.