Background: endogenous psychoses complicated with different addictions have special psychopathological structure including delirious episodes, true hallucinations combined with typical positive symptoms of schizophrenia. These cases are difficult for treatment due to non-compliance of patients and their bad tolerance to drugs. The aim was to study the most effective psychopharmacological treatment using cariprazine for acute psychotic states in paranoid schizophrenia combined with chemical addictions. Patients and Methods: the study was conducted at psychiatric hospitals of Tomsk region, St. Petersburg, Nizhnevartovsk and Noyabrsk from 2018 to 2024. 208 men aged 18 to 45 years suffering from paranoid schizophrenia and dependent on psychoactive substances were examined. The main group made up 104 in-patients, who took cariprazine alone or in combination with haloperidol or chlorpromazine. The control group included 104 in-patients treated with other antipsychotics (aripiprazole, risperidone, olanzapine). Research methods: clinical and psychopathological, psychometric (PANSS, SANS, CGI, GAF), statistical (Python 3.11.0; R version 3.2.4; SPSS Statistics Base 22.0). Results: It was revealed that when comparing the control group with the main group, similar indicators were observed on the CGI and GAF scales on the 2nd week of the study, and on the 4th week of the study, compared with the control group, an improvement in indicators on the PANSS, SANS, CGI, GAF scales was observed. Conclusions: Cariprazine, compared with other atypical antipsychotics (risperidone, olanzapine, aripiprazole), showed a distinct antipsychotic effect in the treatment of acute psychotic states in patients with schizophrenia dependent on psychoactive substances. By the end of the 2nd week after hospitalization, when treating with cariprazine at an average dose of 3 to 6 mg/day in combination with typical neuroleptics (haloperidol, chlorpromazine) or a tranquilizer, the most pronounced antipsychotic effect is achieved. Subsequent isolated use of cariprazine at a therapeutic dose of 3–4.5 mg/day has an effect similar to that of leading atypical antipsychotics by the end of the 4th week of treatment. Unlike other atypical antipsychotics, cariprazine was more effective in the treatment of negative symptoms of schizophrenia, which made it possible to achieve an improvement in overall functioning, increase the duration of remission, and reduce the risk of rehospitalization and the development of hospitalism.
