Trajectories of recovery of social and physical functioning in major depression, dysthymic disorder and double depression: A 3-year follow-up

Abstract

Background

Depressive disorders have a large impact on psychosocial functioning. Since lower functioning predicts recurrence of a depressive episode, insight into the post-morbid course of psychosocial functioning of persons with different depressive disorders may facilitate recurrence prevention.

Methods

Data were derived from NEMESIS, an epidemiologic survey in the adult population in the Netherlands. Respondents, who met the CIDI criteria of major depression (MDD; n = 102), dysthymic disorder (Dysth; n = 66) or double depression (DD; n = 73) at baseline, and recovered during three year follow-up, were included; as was a control group without any diagnosis (NoDiag, n = 4140). Functioning was assessed using the Groningen Social Disability Schedule (GSDS) and the SF-36 physical health summary-scale. Linear Mixed Models were conducted to compare 3-year trajectories of functioning across depressive groups and with NoDiag group.

Results

Compared to NoDiag, all depressed groups were significantly impaired on social and physical functioning. Dysth and DD had a lower level of post-morbid physical functioning compared to MDD (after 1 and 3 years respectively: Dysth: B = − 13.8, p = .002 and B = − 8.11, p = .09; DD: B = − 8.9, p = .03 and B = − 9.1, p = .05). Determinants for impaired social functioning (neuroticism) and for impaired physical functioning (age, comorbid somatic disorders and neuroticism) were identified.

Limitations

Attrition was higher among persons with a depression. Inclusion of the drop-outs would most likely have resulted in stronger associations, since we expect lower functioning among the drop-outs.

Conclusion

This study indicates the long-term debilitating effects of psychopathology, even after recovery of depressive disorders. Duration of the index symptoms appears to be associated with impaired functioning, since especially those with Dysthymia (either with or without a MDD) showed slower and less recovery of functioning.

Introduction

Depressive disorders have a large impact on both social as well as physical domains of functioning (Coryell et al., 1993, Judd et al., 1996, Rapaport et al., 2005, Wells et al., 1992) similar to or even exceeding the impact noted in common medical illnesses (Buist-Bouwman et al., 2004, Buist-Bouwman et al., 2006, Merikangas et al., 2007, Ormel et al., 1994, Schonfeld et al., 1997, Wells et al., 1989, Wells et al., 1992). The level of functional impairment is positively associated with the severity of depressive disorders (Judd and Akiskal, 2000, Kruijshaar et al., 2003, Ormel et al., 1994, Ormel et al., 2004, Rapaport et al., 2005, Spijker et al., 2004a). Additionally, chronicity of the depressive disorder might affect the level of functioning of persons with depressive disorders (Rytsala et al., 2006). However, literature on this issue is not conclusive. Some studies have demonstrated that chronic depressive disorders, such as dysthymic disorder and double depression, have a larger impact on social and physical functioning than non-chronic depressive disorders (Bijl and Ravelli, 2000a, Buist-Bouwman et al., 2004, Buist-Bouwman et al., 2006, Wells et al., 1992, Yang and Dunner, 2001), but others did not (Spijker et al., 2004b).

After remission of the depressive symptoms, social and physical functioning returns to levels found among healthy subjects, although some functional impairment may persist after recovery (Buist-Bouwman et al., 2004, Coryell et al., 1993, Hirschfeld et al., 2002, Judd et al., 2000, Ormel et al., 2004). This postmorbid impaired functioning may be a trait, state or scar effect (Ormel et al., 2004), or a consequence of a so-called “trajectory of recovery”, in which recovery of functioning parallels, but lags considerably behind the curve of depressive symptoms recovery (Bijl and Ravelli, 2000a, Mintz et al., 1992). However, long-term follow-up comparisons of post-morbid functioning across different depressive subtypes are lacking. To what extent severity and/or chronicity of the various depressive subtypes predict post-morbid functioning is unclear. In addition, improvement in depressive disorders has been especially associated with improvements in the social domain of functioning, and to a lesser extent in the physical domain (Simon et al., 2005), illustrating the need to differentiate between social and physical domains of functioning.

Since persistence of a lower level of functioning predicts recurrence of a depressive episode, even after the symptoms of depression are alleviated (Faravelli et al., 1986, Judd et al., 2000, Judd and Akiskal, 2000, Solomon et al., 2004, Spijker et al., 2004b), insight into the course of social and physical functioning of persons with depressive disorders, and into the determinants of an impaired recovery of functioning may facilitate recurrence prevention and limit the burden of disease.

Most studies on functional impairment have a cross-sectional study design and focus on out-patients with depressive disorders, in particular non-chronic major depressive disorder, lacking comparison across different depressive subtypes in the general population. In the present paper, we compare the 3-year “recovery trajectories” of social and physical functioning of persons who reach remission of a baseline diagnosis of Major Depressive Disorder (MDD), pure dysthymic disorder (Dysth), dysthymic disorder with a superimposed MDD (double depression (DD)) and persons without any diagnoses (NoDiag). By comparing both non-chronic and chronic, as assessed by the absence or presence of Dysth, as well as mild and severe depressive disorders, as assessed by the absence or presence of MDD, the interplay between these two factors on functioning can be tested. First, we hypothesized that at baseline, persons with a current chronic and severe depressive disorder (DD) have a lower level of social and physical functioning than persons with a current chronic, but mild depressive disorder (Dysth), who in turn have a lower level of functioning than persons with a current non-chronic, but severe depressive disorder (MDD) (Bijl and Ravelli, 2000a, Wells et al., 1992). Second, we compare the 3-year follow-up of social and physical functioning between persons with depressive disorders and persons without any diagnosis. We hypothesized that post-morbid functioning of all depressive disorders gradually returns to the level of persons without any diagnosis, but some functional impairment, as compared to persons without any diagnosis will prevail (Friedman et al., 1999, Ormel et al., 2004). Furthermore, we hypothesized that the recovery of social and physical functioning of persons with chronic depressive disorders lags behind the recovery of social and physical functioning of persons with MDD (Hays et al., 1995, Rytsala et al., 2006). Third, besides chronicity and severity, other possible determinants of recovery trajectories of social and physical functioning (demographic, clinical and personality characteristics) will be explored.