پیش بینی افکار خودکشی: ناپایداری خلقی در مقابل روان رنجوری

The personality trait neuroticism predicts depression and suicidal thoughts. Neuroticism is also linked to mood instability (MI)1 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.

This study investigates the association between mood instability (MI) and neuroticism and how these traits relate to suicidal thoughts. To borrow an analogy from Ebner-Priemer, Eid, Kleindienst, Stabenow, and Trull (2009), think of the weather as an analogy for moods. Suppose that you go to a resort that has unpredictable rain for half the days over two weeks while your friend goes to a resort that has one week of rain and then a week of sunshine. The holiday experiences will be different for the two of you even though the amount of rainfall might have been the same. Just like reporting the average rainfall, depression is usually evaluated with interview schedules (Sheehan et al., 1998) and scales (Beck, Steer, & Garbin, 1988) that ask patients to mentally average their experience of depression over two weeks. The negative bias to depression tends to outweigh fluctuations in mood (Solhan, Trull, Jahng, & Wood, 2009), resulting in a response that is slanted towards more severe continual depression. In contrast, studies that incorporate prospective, frequent measurements reveal that the depressive experience varies within the day or every few days (Bowen et al., 2006 and Trull et al., 2008). These fluctuations are described as mood instability (MI) that is defined as “extreme and frequent fluctuations of mood over time” (Trull et al., 2008). MI has been described in depression occurring alone or comorbid with other conditions including borderline personality disorder (Ebner-Priemer et al., 2009), alcohol abuse (Bowen, Block, & Baetz, 2008), anxiety (Bowen et al., 2006) or depression with mood swings (MI) (Bowen, Mahmood, Milani, & Baetz, 2011). This literature indicates that MI and depression are separate but related concepts and that current formulations of depression do not adequately account for the MI component. Frequent, unpredictable, sudden descents in mood are distressing (Craske, Brown, Meadows, & Barlow, 1995) and are associated with suicidal thoughts in patients with depression (Trull et al., 2008). This might occur by affecting how people perceive events, their perceived control over emotions, or their event attributions (DeNeve & Cooper, 1998). MI has been found to be a significant predictor of suicidal acts in university students and in diverse groups of patients with depression, personality disorders and bipolar disorder (MacKinnon et al., 2005, Sampson et al., 2004, Witte et al., 2005 and Yen et al., 2004). Conversely, emotional stability that has been conceptualized as the reverse of the Eysenck Neuroticism Scale is an important predictor of happiness (Eysenck and Eysenck, 1985, Hills and Argyle, 2001 and Vitterso, 2001), and minor and major depression are associated with higher emotional reactivity (Bowen et al., 2004 and Bylsma et al., 2011). These observations suggest that measures of MI may be clinically relevant in studies of depression and suicide (Trull et al., 2008). Eysenck derived his concept of neuroticism from mathematical clustering studies but interestingly, he used the term to refer to unstable moods (Eysenck & Eysenck, 1985). Cullen in the 1700s first used the term neurosis to mean a class of diseases that could not be explained physiologically (Kendell, 1991) and Freud and his followers later used it as an explanation for symptoms related to unconscious conflicts (Makari, 2008). Neuroticism and similar traits of negative affect or emotional instability are a large first component of most common personality inventories (Costa and McRae, 1992 and Trull et al., 2008). More recently the term neuroticism has been used as a superordinate organizing concept linking anxiety and depressive syndromes (Krueger, 1999). In longitudinal studies it is clear that neuroticism predicts both depression (Caspi et al., 1996 and Quilty et al., 2009) and suicidal thoughts (Brezo et al., 2006 and ten Have et al., 2009). MI is less well researched than neuroticism, but is also associated with depression (Bowen et al., 2011) and suicidal thoughts (Links, Eynan, Heisel, & Nisenbaum, 2008). Neuroticism has been directly linked to MI but most relevant studies on this topic were done with student or general population samples rather than with patients (Eysenck and Eysenck, 1985, Miller et al., 2009 and Murray et al., 2002). Therefore, the question of whether MI forms an essential component of neuroticism in patients with depression has not been addressed. In this study, we investigated the relationship between MI, neuroticism, depression and suicidal thoughts in a group of depressed patients. We postulated that MI is the essential component of neuroticism accounting for the association between neuroticism and suicidal thoughts, and that MI would predict suicidal thoughts even after controlling for neuroticism.