MDD is often associated with an impaired patient biopsychosocial functioning, and with reductions in health-related quality of life. Nonetheless, the importance of assessing MDD influence on HRQoL and the role of MDD clinical symptoms on HRQoL has only recently been recognised [6, 16].
A recent European observational study, EUFINDER, carried out in 12 countries, evaluated the changes of HRQoL in outpatients receiving pharmacological treatment for a depressive episode in routine primary care and specialist settings.
Receiving an AD treatment was associated with large improvements in HRQoL, as assessed by the SF-36 and the EQ-5D [8, 7, 10]. In order to understand in a specific cultural context, such as Italy, the changes in the measures as assessed in the FINDER study, we have confirmed clinical and functional impairments and poor HRQoL in the baseline assessment .
In this study we examined the follow-up data on the Italian FINDER sample in order to verify the role of depression on HRQoL and found that patients with a clinical diagnosis of depression experienced improvements in HRQoL after starting an antidepressant treatment. More specifically, several dimensions of HRQoL were shown to improve in a 6-month period, including SF-36, scores, especially mental health scores and EQ-5D HSI.
These results are consistent with a recent longitudinal study , which found reduced EQ-5D scores in Swedish primary care patients with depression compared to the general population and comparable HRQoL improvements after 6 months of treatment.
Interestingly, our study also showed that the switch of antidepressant within AD groups was consistently associated with a smaller improvement in SF-36 MCS and EQ-5D VAS and HSI compared to patients not switching treatment. Furthermore, between-group AD switch was associated with a worse SF-36 MCS and EQ-5D HSI compared to no switch. This data may be due to the higher severity of depression in patients requiring a switch of treatment, to an inappropriate diagnosis or to inadequate doses/exposure times or inappropriate exposure time rather than to the switching itself. A second result of our study was that HADS-A scores at baseline were positively associated with HRQoL improvements at 6 months. This might be partially due to a positive effect of participating in the trial, but also to the positive effects of antidepressant treatments on anxiety.
A third finding is that the presence of a previous psychiatric illness in the 24 months before baseline was predictive of poorer HRQoL outcomes, with respect to EQ-5D VAS and, to a lower degree, to SF-36 PCS.
Another result of our study indicates that a higher severity of somatic and painful symptoms at baseline, as evaluated by patients, was associated with poorer HRQoL outcomes during antidepressant treatment. We also found that the presence of a chronic medical disease is associated with poorer HRQoL, as far as SF-36 PCS and EQ-5D HSI are concerned. This confirms other research highlighting the role of somatic and painful symptoms in the QOL of depressed patients and their possible implications on depression outcomes [7, 10, 18, 19].
There are some limitations that need to be considered in interpreting the results of the study presented here. First, important data such as the association between HRQoL outcomes and AD switching need to be further investigated in more controlled settings. A second limitation is that this study did not include a control group, for example a group of patients not starting an AD treatment. As a third limitation, HRQoL measures evaluate concepts also included in instruments that assess depression. However, SF-36 and EQ-5D focus more on the patients' daily living, social interactions and related aspects. Symptom severity and impact on everyday life are probably closely correlated, which may explain much of the parallel improvement in HRQoL and depression symptoms. Furthermore, the broad number of rating scales used in the study limited the practicability of a longer follow-up. This may have in part conditioned findings related to the effects of antidepressant treatment on HRQoL. Lastly, during our observation period, patients did not reach the general population average of 50 for the SF-36 MCS (MCS mean value at 6 months = 39.3). Thus, a longer observation period might be needed to assess whether, for patients with depressive disorders, the time for achieving mental HRQoL outcomes comparable to the general population is longer than 6 months or whether, even after treatment with antidepressants, in these patients HRQoL remains impaired.