[Residual symptoms after a treated major depressive disorder: in practice ambulatory observatory carried out of city].

INTRODUCTION

The main therapeutic objective for depression is remission (absence of clinical signs of the disorder and low scores on assessment scales), yet partial remission rates remain high (insufficient criteria for diagnosing the disorder while clinically and psychometrically assessable symptoms continue to linger. The presence of residual symptoms is associated with a higher relapse rate of depression, occurring up to 5 times earlier, an increased suicide rate, significant use of healthcare services and a marked social impairment. The most frequently reported symptoms are specific to depression, i.e. anxiety and irritability, depressed mood, feelings of guilt and loss of interest in activities, asthenia and difficulty falling asleep at night. Residual symptoms constitute a valid and reliable clinical marker of prognosis (especially for relapse and chronicity) and must be treated with specific therapeutic strategies. Studies on depression with residual symptoms are few and mainly focus on populations of hospitalized patients or those with a severe form of depression. Since little work has been done with regard to patients monitored on an outpatient basis, we felt it was appropriate to select a population of depressed patients from private psychiatric practice. Our main objective was to analyze the frequency of residual symptoms after 8 to 12 weeks of antidepressant treatment and to study the clinical and socio-demographic characteristics of these subjects.

DESIGN

1 790 patients who had presented with one major depressive episode per DSM IV criteria and who had been receiving antidepressant treatment for 8 to 12 weeks were included and evaluated. 463 private psychiatrists practicing in metropolitan France were randomly selected and stratified by region and sex ratio (30% female and 70% male) to obtain a sample as representative as possible of the French psychiatrist population. The following were measured and assessed: anthropometric and socio-demographic characteristics, the history of depression, a description of the last major depressive episode, a description of its management, current clinical variables, the Hamilton Depression Rating Scale (HDRS) score, the physician's assessment of residual symptoms, and a description of the patient's management on the day of the appointment.

RESULTS

Following acute treatment, evaluation of depressive symptoms on the Hamilton scale showed that 549 (32%) of subjects had a score below 8; 792 patients (46.7%) had a score between 8 and 18; and 354 (20%) had a score above 18. Patients in the first group (HDRS<8) who were considered to be in remission started treatment early (chi2=18.28, DOF=4, p<0.01) for a first episode (51.3%) with a low number of initial symptoms (chi2=27.03, DOF=6, p<0.01). The evaluators found persistent depressogenic factors (chi2=15.9, DOF=2, p<0.01) and significant psychiatric co-morbidity (chi2=18.28, DOF=4, p<0.01) in subjects in partial remission (HDRS between 8 and 18). The non-responders (HDRS>18) presented a history of more depressive episodes (chi2=17.04, DOF=4, p<0.01) and a delay of more than 30 days before treatment was initiated (chi2=18.2, DOF=4, p<0.01). With regard to the nature of residual symptoms, at least 50% of subjects in partial remission were very symptomatic for depressive mood (65.4%), psychic anxiety (56.6%), and loss of interest and time away from work (49.4%). Indicators of severe depression (early morning insomnia, psychomotor retardation, agitation, hypochondriasis, weight loss and lack of awareness of the disorder) were reported less frequently, and usually not at all. Conclusion - These results illustrate three important points. First, a significant percentage (46.7%) of patients who responded to treatment subsequent to the acute period presented with residual symptoms. Second, these symptoms are included in the areas of depressed mood - psychic anxiety . Third, a delay in initiating treatment seems to have an effect on response. These results confirm the need to develop strategies to screen for these residual forms for these residual forms of depression, as well as specific methods to treat them.