[Relapse in psychotic depression and comparison with non-psychotic depression]

Psychotic depression (PD) is a severe disease with a lifetime prevalence between 0.35 and 1%. The guidelines recommend combination therapy with an antidepressant and an antipsychotic, whereas in non-psychotic depression (NPD) an antidepressant is advised as monotherapy.

To determine whether there is a difference in relapse rates between PD and NPD, and which treatment is associated with the lowest relapse rate.

A systematic literature search across 6 databases (PubMed, Web of Science, Scopus, Embase, Cochrane, and CINAHL) and a meta-analysis were conducted to compare relapse rates between PD and NPD.

Eight studies with a total of 468 patients and 147 relapse events were included in the meta-analysis. No statistically significant difference could be demonstrated in relapse rates between PD and NPD. The difference in relapse rates in PD between various treatments was not statistically analyzed, but qualitatively described. There was a wide variation in treatment methods and a broad range of relapse rates.

Based on our findings, there is no statistically significant difference in relapse rates between patients with PD and NPD. However, caution is warranted with this conclusion, as the meta-analysis is based on a limited number of studies with high variability in the outcome measure. It seems important to continue acute treatment after response or remission, but which treatment modality best prevents relapse remains unclear.