Specific depressive symptoms and disorders as associates and predictors of suicidal acts across adolescence

Abstract

Objective

To examine the role of depressive symptoms and disorders as associates and predictors of suicidal acts across adolescence.

Method

A representative sample of Norwegian school students (N = 2464, mean age 13.7 years) in grades 8 and 9 was reassessed after one year (T2) with the same questionnaire. All high scorers of depressive symptoms on the Mood and Feelings Questionnaire (MFQ) at T2 were defined as cases. One control from low or middle scorers, matched for age and gender, was randomly assigned to every two cases. This subset (n = 345) was diagnostically assessed by face-to-face K-SADS-PL interviews (mean age = 14.9 years). The same subset was reassessed after 5 years (T3) by using the same questionnaire (n = 252, mean age = 20.0 years) and telephone K-SADS-PL interviews (n = 242). The participation rate was 76.9% (n = 265).

Results

Cognitive symptoms dominated the depressive symptom profile among suicide attempters, irrespective of age and time. Among younger adolescents, suicidal thoughts and acts of self-harm without suicidal intent were associated with suicidal acts. Recurrent thoughts about death, hopelessness, disturbed concentration and middle insomnia were associates of suicidal acts among older adolescents.

Worthlessness by 15 years was a significant predictor of suicidal acts between 15 to 20 years. MDD and a depressive episode, not otherwise specified, continued to be significant associates among younger adolescents, while dysthymia by 15 years remained a predictor of suicidal acts between 15 to 20 years, even when controlled for depressive symptoms.

Conclusions

Self-harm without suicidal intent, middle insomnia, cognitive depressive symptoms and a formal psychiatric diagnosis of any depressive disorder should alert professionals in the risk assessment of suicidal adolescents.

Introduction

The assessment of suicidal youth is one of most common and demanding emergencies in adolescent mental health services (Brent, 2001). The ratio of suicide attempts to suicide completions is higher in adolescence than in any other age group (King, 1997). The prevalence of suicide attempts starts increasing from the age of 14 years onwards (Lewinsohn et al., 2001a). Up to 32% of clinically referred adolescents will attempt suicide at least once by early adulthood (Kovacs et al., 1993), while 20% will repeat the attempt (Harrington et al., 1994). In community settings, 70–91% of youth who attempt or think about suicide have a psychiatric disorder (Gould et al., 1998). Research on suicidal phenomena among adolescents has mainly explored for other risk factors associated with depressive disorders (Brent et al., 1994, Lewinsohn et al., 2001a, Bridge et al., 2006), since most persons with mood disorders do not commit suicide and about half of them never attempt suicide (Rihmer, 2007).

Depressed mood has been found to be the most common depressive symptom among 11 to 18 year old adolescent inpatients and outpatients who have attempted suicide (Bettes and Walker, 1986). Among adolescent emergency unit inpatients, high levels of self-reported depressive symptoms predicted suicide attempts in a 2 to 4 year follow-up (Ivarsson et al., 1998). Among 13 to 17 year olds, hopelessness, negative self-esteem and violent behaviour were more common among depressed, suicidal adolescents than among those who are depressed but non-suicidal (Csorba et al., 2003). A recent review on sleep and suicidal behaviour among youth has called for the use of longitudinal studies due to inconsistencies in findings of cross-sectional studies, wherein the associations with insomnia often disappeared when controlled for depression (Liu and Buysse, 2006).

Major depressive disorder (MDD) and dysthymia were specifically associated with higher rates of suicidal behaviours than other diagnoses among outpatients aged 8–13 years, followed up for five years (Kovacs et al., 1993). MDD has also been significantly associated with suicidal acts among older school adolescents (Lewinsohn et al., 1994).

Although current empirical research has added considerably to our knowledge on sucidality among adolescents, gaps continue to exist about specific aspects which can potentially aid the clinician in the assessment of suicide risk among adolescents, for example: are there specific depressive symptoms and disorders related to suicidal acts? Do these relationships differ with age and time? To the best of our knowledge, longitudinal studies exploring the role of specific depressive symptoms and disorders as associates and predictors of suicidal acts among adolescents have not yet been reported.

The aim of the current study was, therefore, to examine relationships between specific depressive symptoms and disorders with suicidal acts in a sample of depressed school adolescents and non-depressed controls followed for a five-year period into early adulthood. We first studied the prevalence of depressive symptoms and disorders in adolescents with high mean scores on depressive symptoms as compared to those with low to moderate mean scores as reported in a questionnaire. The next objective was to examine the specificity of depressive symptom and diagnostic profiles as associates of suicidal acts at two developmental phases, i.e., by 15 years and for the next 5-year period as assessed retrospectively at 20 years of age. Thirdly, we explored the role of specific depressive symptoms and disorders by the age of 15 years as potential prospective predictors of suicidal acts between 15 to 20 years of age. Finally, we investigated the role of self-harm without suicidal intent as an associate and predictor of suicidal acts, across age and time, given its complex relationship with suicidal acts (Grøholt et al., 2000, Jacobson and Gould, 2007, Larsson and Sund, 2008).