The principal findings of the DéPasS study were the high proportion of patients with mood or anxiety disorders in primary care who reported severe disability and who reported a significant improvement of disability following initiation of an antidepressant treatment.
For patients with a major depressive episode, the results from this study are consistent with the WMH surveys, which reported that 65.8% of individuals with major depressive disorder in high-income countries reported severe disability,8
and with clinical trials of patients suffering from a major depressive episode, who presented SDS dimension scores at baseline ranging from 6.0 (work/school dimension) to 6.8 (social activities dimension).13
Although previous data would suggest that patients with anxiety disorders report less disability than those with major depressive disorder, we did not find major differences in SDS dimension scores between the various diagnostic groups included in the study.1
This may be explained by extensive comorbidity of depression with anxiety disorders in our patients, in contrast with those included in clinical trials, where investigators are careful to exclude patients with comorbidities.
After initiation of antidepressant treatment in our patient cohort, the proportion of patients reporting severe disability on any dimension in the previous week declined from 66.3% to 7.0%, a mean decrease in SDS score of 3.9–4.2 (according to the dimension), a response rate of 90.0%–92.8%, and a remission rate of 17.1%–19.5%. These treatment effects are generally consistent with those reported in randomized clinical trials of selective serotonin reuptake inhibitors and serotonin/noradrenaline reuptake inhibitors in anxiety disorders or in major depressive disorder.13
Two large observational studies have evaluated self-reported disability with the SDS, both of which included over 5000 patients with major depressive disorder starting treatment with selective serotonin reuptake inhibitors.17
The first, conducted in the US, reported a baseline SDS score of 6.0–6.8 (depending on the dimension), a decrease in score 8 weeks after starting treatment of 2.5–2.9 points, and a proportion of patients with mild or no disability (score < 4) of 51%–58%.17
The second study, performed in Greece, reported a proportion of patients with mild or no disability after 12 weeks of treatment of 80%–84%.18
The results of the DéPasS study are consistent with these previous findings. Nonetheless, it should be noted that, for the DéPasS study, as for other noncomparative observational studies, a causal relationship between antidepressant treatment and reduction in disability cannot be demonstrated formally in the absence of an untreated control group.
Reductions in disability were already observed at the 6-week follow-up visit. It is possible that further improvement would have been seen if follow-up was continued up to 24 weeks, as recommended in current practice guidelines.19
Moreover, the mean number of days “out of role” due to symptoms and the mean number of days with reduced productivity in the previous week were reduced by a factor of four after 12 weeks of treatment, to less than one day per week. These findings are again consistent with the previous Greek study.18
The extent of the decrease in SDS score was correlated with the reduction in psychiatric symptoms, as measured by the CGI-I, as reported in previous studies.21
In parallel, the proportion of patients with clinically significant symptoms (HADS score ≥ 7) decreased to <30%. These observations suggest that the SDS is both a relevant and valid measure of disease-related disability in this patient population.
The finding that self-reported disability is improved to a significant extent after starting antidepressant treatment, together with the observation that around two-thirds of patients in the study were severely disabled, suggests that such treatment is both justified and useful, and that clinical practice observed in a primary care context in this study is appropriate and effective.
At inclusion, we noted that even patients rated by their physicians as mildly ill report significant disability. The observation of significant disability in patients with mild depression or anxiety disorders has been made previously.23
More surprising was the finding of an apparent “floor effect”, with patients rated between 1 (not ill) and 4 (moderately ill) on the CGI-S having essentially similar levels of self-reported disability. This finding needs to be interpreted with caution, firstly because of the low patient numbers at the bottom end of the CGI-S scale and, secondly, because it is unclear why a physician who diagnosed a patient with a mood or anxiety disorder sufficiently severe to warrant treatment would rate the patient at 1 on the CGI-S (normal, not ill at all). This may suggest that the CGI-S was not understood or used appropriately in some cases.
Given the naturalistic setting of the study, participating general practitioners made a diagnosis on the basis of their own experience and judgment, rather than using a standardized diagnostic algorithm, and no attempt was made to ascertain whether the diagnoses given actually corresponded to DSM-IV Text Revision criteria. However, a survey of primary care physicians prescribing selective serotonin reuptake inhibitors in France revealed that operational diagnoses of general practitioners were generally consistent with a DSM-IV Text Revision diagnosis made a posteriori.24
The DéPasS study has several strengths and limitations. Its strengths include the large number of participating general practitioners and patients (>8000) and the naturalistic treatment setting. The investigator sample corresponds to approximately 3% of all general practitioners in France. Nonetheless, because physicians who declined to participate may see different types of patients or have different treatment practices than participants, these results may not be representative of all general practitioners. Although the proportion of patients who failed to return for a follow-up visit was relatively low (−20%), it cannot be excluded that treatment outcome differed between the patients analyzed and those who failed to return for a follow-up visit.
In conclusion, this large naturalistic study in primary care in France showed that patients presenting to general practitioners for mood and anxiety disorders report significant disability and that this can be reduced effectively and rapidly after antidepressant treatment is initiated. Relief of self-reported disability is correlated with clinical improvement.