A significant proportion of patients with schizophrenia have depressive symptoms [Lindenmayer, J.-P., 1991; Siris S.G., 2000; Majadas, S., 2012; Miura I., 2021; Liu, 2021]. If in the postpsychotic period depression is found in approximately 20% of patients with schizophrenia, then at the time of exacerbations its frequency increases to 60%, and in total in the anamnesis, especially at the initial stage,. When taking into account the anamnestic data, especially the initial stage, the incidence of depression reaches 80% of patients with schizophrenia suffer from depression [Upthegrove, R., 2017]. Depression is now considered part of the main symptomatology of schizophrenia, added as one of the dimensions in the diagnosis of schizophrenia spectrum disorders [Tandon, R., 2013; Upthegrove, R., 2017; Liu, 2021]. As it turned out, neither the traditional dichotomy of affective disorders and schizophrenia, nor their polarization with the "introduction" of an intermediate diagnostic category - schizoaffective psychosis, nor the now prevailing concept of a wide range of intermediate phenotypes with different representations of psychotic and affective disorders, or a multidimensional phenomenological continuum from conditionally " pure" schizophrenia to the same "pure" bipolar disorder [Reininghaus, U., 2016, 2019; Tamminga, C.A., 2013]. It remains problematic to single out a reference or key feature that makes it possible to distinguish related forms of psychotic and affective disorders. For example, symptoms of depression in patients with schizophrenia are associated with cognitive impairment and in real clinical practice, when assessed at the current moment, are difficult to distinguish from typical negative symptoms of schizophrenia.

BACKGROUND: Depression in patients with schizophrenia worsens the course of the disease by increasing the risk of suicide, by complicating the clinical picture of the disorder, and by reducing the quality of the social functioning; its treatment is difficult, since monotherapy, even when involving modern antipsychotics, does not always prove successful. While the prescription of additional antidepressants (ADs) can improve the likelihood of a better outcome, the effectiveness of such augmentation in many cases is yet to be proven. Therefore, it is still important that one weighs the effectiveness of various combinations between most of the known ADs and some second-generation antipsychotic (SGA) in the treatment of depression that occurs at different stages of schizophrenia. In previous studies, the use of vortioxetine as an adjunct to an antipsychotic yielded a reduction in negative symptoms, a clinically significant improvement in cognitive functions that differed from its antidepressant effect, and good tolerability, which affects how committed to treatment a patient remains. AIM: To study the changes that occur over time in the clinical manifestations of depression, negative and cognitive impairment, as well as the social adequacy of patients receiving a combination therapy with second-generation antipsychotics and vortioxetine, which were prescribed in real clinical practice at doses approved in the Russian Federation. METHODS: We performed a comparative analysis of the changes in depression symptoms and negative symptoms, cognitive impairment, as well as function of 78 patients with severe manifestations of depression at the stage of exacerbation reduction and subsequent remission of paranoid schizophrenia. Combination treatment with SGA and vortioxetine was used in 39 patients, and 39 patients who had similar clinical manifestations received just SGA. During the observation period, the mental disorder severity and depression symptom severity were assessed 3 times (before the start of treatment, after three months, and after six months) using the Clinical Global Impression (CGI) scale and Calgary Depression Scale for Schizophrenia (CDSS), respectively; patients were also assessed using the Negative Symptoms Assessment-5 (NSA-5) scale, Perceived Deficits Questionnaire-20 items (PDQ-20) scale, and Personal and Social Performance (PSP) scale. RESULTS: According to the ANOVA results, by the end of the observation period, patients, regardless of their therapeutic group, showed a statistically significant decrease in the level of depression on the CDSS scale, the severity of negative symptoms on the NSA-5 scale, cognitive symptoms on the PDQ-20 scale, as well as an improvement in personality and society, judging by the increase in the total PSP scores. There were also significant differences between the compared main (SGA + vortioxetine) and control (SGA) groups in terms of the changes in the total score on the CDSS and PSP scales. An interesting aspect of the changes in the clinical scores was a noticeable improvement in the SGA + vortioxetine group after 3 months of treatment, in the absence of a similar improvement in the control group, and the achievement of approximately the same scores in both groups after 6 months. In particular, there were significant differences between the SGA + vortioxetine and SGA groups in terms of the mean CDSS (p 0.001), NSA-5 (p=0.003), PDQ-20 (p 0.001), and PSP (p=0.004) scores after 3 months. Analysis of the time before early withdrawal from the study showed that significantly more patients in the SGA + vortioxetine group completed the study program (n=27, 69.23%) compared with the SGA group (n=13, 33.33%) (2 =14.618, df=1, p 0.001, log-rank test. The mean survival time in the SGA group was significantly (p 0.001) less and amounted to 101.436 days (95% CI: 81.518121.354), and in the SGA + vortioxetine group it amounted to 161.744 days (147.981175.506). The relative risk of full study completion in the vortioxetine + SGA group compared with that in SGA was 3.618 (1.8716.994). CONCLUSION: The addition of vortioxetine to the SGA therapy accelerates the reduction of the depression symptoms that occur at the stage of psychosis regression and early remission, contributes to the accelerated reduction in negative symptoms, positively affects the subjective assessment of cognitive impairment severity, and has a significant positive effect on the level of psychosocial functioning.