Ongoing or re-emerging subjective insomnia symptoms after full/partial remission or recovery of major depressive disorder mainly with the selective serotonin reuptake inhibitors and risk of relapse or recurrence: A 52-week follow-up study

Abstract

Background

Many patients who remit fully/partially or recover from an episode of major depression continue to suffer from sleep problems, mainly insomnia. Our study assesses the frequency and types of ongoing or re-emerging subjective insomnia symptoms and their relationship to subsequent depressive relapse or recurrence in a group of full/partial remitters or recoverers.

Method

Sixty patients, 18 to 65 years of age, with current MDD defined using DSM-IV-TR criteria were participated in the study. They began a 24-week course of open-label acute plus continuation phase treatment mainly with SSRIs. Maintenance treatment was not planned for not affecting natural relapse or recurrence rates. All participants were evaluated by CGI-S, BDI, HAMD-17, PSQI, and ISI at weeks 0, 4, 12, 24, and 52.

Results

Majority of the participants (83.33%) had subjective sleep disturbance, insomnia prior to relapse or recurrence. Repeated measures ANOVA was used to evaluate changes in scores of depression and sleep scales over time between recurred (N = 12) and non-recurred groups (N = 48). Differences between means were calculated with post hoc Bonferroni comparison test. The changes in scores of entire clinical scales over time between recurred and non-recurred groups were statistically significant.

Limitations

The limitations of this study include the use of a relatively small, mostly young female sample and the lack of an objective sleep measure to corroborate self-report scales.

Conclusions

Early recognition and treatment of disturbances of the sleep–wake cycle may be important for treatment and prevention of recurrence of depression.

Introduction

Major depressive disorder (MDD) is a severe, recurrent, and disabling medical illness that is highly prevalent worldwide and often associated with a negative impact on medical health, quality of life, and productivity (Machado-Vieira et al., 2008). The lifetime risk of developing a MDD is as high as 25% in women and 12% in men (American Psychiatric Association, 2000a), and according to the WHO, depressive disorders are the fourth leading cause of disability-adjusted life years worldwide, and by 2020 are estimated to be second only to ischemic heart disease (Kurian et al., 2009). A recent analysis on the effect of mood disorders on work performance conducted by Kessler and colleagues revealed that MDD is associated with 27.2 lost work-days per ill worker per year (Kessler et al., 2006). This is of great concern and constitutes a major public health issue, since the incidence of depression is expected to increase as a result of prolonged life expectancy and social and demographic changes (Mendlewicz, 2009).

There is strong evidence of association between sleep disturbance and MDD (Lustberg and Reynolds, 2000, Riemann et al., 2001, Tsuno et al., 2005). It has been reported that up to 90% of depressed patients complain about sleep disturbance (Almeida and Pfaff, 2005, Tsuno et al., 2005), and insomnia often appears before the onset of MDD symptoms (Ohayon and Roth, 2003). Sleep disturbance is a risk factor for MDD (Breslau et al., 1996, Cole and Dendukuri, 2003). For instance, a review of 8 longitudinal epidemiological studies showed that the presence of insomnia symptoms at baseline significantly predicted an increased risk of depression at follow-up 1–3 years later (Riemann and Voderholzer, 2003). Finally, sleep disturbances are associated with suicidal behaviour in patients with MDD (Agargun et al., 1997a) and suicidal depressive patients have also significantly higher rates of poor subjective sleep quality (Agargun et al., 1997b). Insomnia represents here one of the most commonly reported residual symptoms after remission from depression. In a recent study in patients in remission after completing at least 20 weeks of therapy, 22%, 26% and 17% suffered from initial insomnia, from middle insomnia, and from terminal insomnia, respectively (Carney et al., 2007). More than 40% of patients reported symptoms of fatigue and sleepiness/sedation in partial or full remission (Fava et al., 2006). Residual symptoms of insomnia after a MDD episode increase the risk of both relapse and recurrence (Armitage, 2000, Dombrovski et al., 2007, Ohayon and Roth, 2003).

Therefore, the aim of this report was to assess the frequency and types of ongoing or re-emerging subjective insomnia symptoms and their relationship to subsequent depressive relapse or recurrence for a small representative group of full/partial remitters or recoverers who had participated in a 52-week, single-centre, open-label, and randomised trial and who were treated mainly with the selective serotonin reuptake inhibitors (SSRIs) using measurement-based care.