A five-year follow-up of the verbal memory performance of individuals with bipolar disorder and schizophrenia: evidence of unchanging deficits under treatment

ABSTRACT

Objective: Bipolar disorder (BD) and schizophrenia (SZ) are chronic and heterogeneous mental disorders that present cognitive and functional impairments. Verbal memory is considered an important predictor of functioning and a domain vulnerable to the aging process. However, only few studies investigate the progression of memory longitudinally in BD and SZ, especially in lower- and middle-income countries. Therefore, we aim to evaluate the course of verbal memory in individuals with BD and SZ. Methods: We assessed 31 individuals with BD and 27 individuals with SZ under treatment at outpatient clinics at baseline and after five years. They were assessed through a sociodemographic questionnaire, memory and estimated IQ (eIQ) instruments, and clinical scales. Results: Individuals with SZ showed worse verbal memory performance in comparison to BD, however, we did not observe changes over time within patient groups. Individuals with BD with higher eIQ showed a better verbal memory performance, while no effect of eIQ was found for subjects with SZ. Conclusion: Patients with SZ and BD showed different levels of verbal memory impairment, although they had similar unchanging trajectories after 5 years under psychiatric treatment. This finding indicates a relative stable cognitive course for both disorders.

KEYWORDS:

• Schizophrenia
• bipolar disorder
• verbal memory
• longitudinal

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001, Hospital de Clínicas de Porto Alegre (FIPE nº15-0298 and nº 15-0282), and Brazilian National Council for Scientific and Technological Development (CNPq - 423969/2018-8).