Neurocognition in inpatients with severe mental illness with a co-occurring and substance use disorders in a subacute psychiatric unit

Objective: Cognitive dysfunction in schizophrenia, schizoaffective disorder and bipolar disorder has been consistently reported during the last 30 years, before the onset of the diseases and in their evolution, with less consensus when these disorders co-occur with substance use disorders, with some studies reporting lower or better neurocognitive performance depending on the substances. Declarative memory and executive function are usually the most dysfunctional neurocognitive domains, less or greater severity.

Participants and Methods: Retrospective analysis of consecutive cases evaluated during the years 2018-2021 in the subacute psychiatric hospital unit the Benito Menni CASM. The variables included in the study were: the score on the copy and the delayed memory score of the figure of RBANS battery; verbal fluency 'animals' and lexical 'p'; number of correct productions on the Five-Point Tests of nonverbal fluency and the copy and designation of a geometric cube. The data was analyzed with version 21 of the program IBM SPSS statistics. In accordance with current legislation, this study guarantees the confidentiality of the personal data involved.

Results: A total of 131 patients were included, 93 men and 38 women, with an mean age of 42 years old. 33.6% of patients are diagnosed with schizophrenia, 32.1% are diagnosed with schizoaffective disorder and 13.7% are diagnosed with bipolar disorder. 51.9% of patients are diagnosed with these disorders co-occurring with substance use disorders and are significantly younger. On average and among all the data, low results are obtained only in the delayed memory and verbal fluency and are not influenced by age. Patients with comorbid diagnosis of substances use disorders get better results in delayed memory and in nonverbal fluency.

Conclusions: The results obtained are partially consistent with those reported in the literature on dysfunctional neurocognitive domains in different populations of severe mental illness with a co-occurring and substance use disorders.