Treatment-resistant depression (TRD) is a complex and debilitating condition with heavily impacting consequences on healthcare and socio-economic system. The overall picture of TRD still appears conflicting and fragmentary and most studies were conducted on outpatients only.
Aim of this study was to investigate the characteristics of real-world inpatients with TRD in order to provide useful information in daily clinical practice and identify any specific feature of this population.
We retrospectively examined clinical charts of 250 MDD inpatients, excluding subjects with any type of bipolar disorder. Patients were grouped in two sub-samples, TRD and non-TRD (nTRD); socio-demographic and clinical characteristics were compared between the two subgroups. Furthermore, therapeutic strategies adopted in TRD patients were analysed. Comparisons were performed by using Pearson’s χ2 test with Yates’ correction for categorical variables and independent-samples t-test for continuous variables.
The prevalence of TRD in our sample was 32.4%. Compared to nTRD subjects, TRD inpatients were significantly older, while unexpectedly other socio-demographic factors, such as lower educational level and unemployment, did not result associated to TRD. Concerning clinical features, TRD subjects had longer duration of illness, more lifetime depressive episodes, older age at first admission and higher rate of family history for mood disorders and for suicide. They also showed greater severity of the current episode, less comorbid psychiatric disorders and more medical conditions. The lack of correlation between suicidality and TRD was an unexpected result. At discharge, TRD was more related to polypharmacy with higher number of psychotropic drugs in particular; add-on was the most frequent strategy (48.1%) and the atypical antipsychotics (quetiapine above all) were the most frequent add-on medications (68.8%).
We observed several peculiar features of TRD in hospitalized patients that have not been described previously. Further research is awaited to investigate such relationships and help detecting valid therapeutic strategies in inpatients.