Cognitive Performance in Euthymic Patients with Bipolar Disorder vs Healthy Controls: A Neuropsychological Investigation
M. Carlotta Palazzo1, 2, §, Chiara Arici1, §, Laura Cremaschi1, Marta Cristoffanini3, Cristina Dobrea1, Bernardo Dell’Osso*, 1, 4, A. Carlo Altamura1
1 Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, via Francesco Sforza 35, 20122 Milano, Italy
2 Centro Sant’Ambrogio, Fondazione Sacro Cuore Fatebenefratelli, Provincia Lombardo Veneta, Cernusco sul Naviglio, Milano, Italy
3 Dipartimento di Neuroscienze e Salute Mentale, Unità di Neuroradiologia. Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, via Francesco Sforza 35, 20122 Milano, Italy
4 Department of Psychiatry and Behavioral Sciences, Bipolar Disorders Clinic, Stanford Medical School, Stanford University, CA, USA
Cognitive impairment may affect patients with Bipolar Disorder (BD) beyond the acute episodes, qualifying as a potential endophenotype. However, which cognitive domains are specifically affected in euthymic patients with BD and the potential influence of confounding factors (e.g., age and concomitant pharmacological treatment) are still a matter of debate. The present study was, therefore, conducted to assess cognitive performance across specific domains in euthymic bipolar patients, not older than 50 years (to avoid potential age-related bias) versus healthy controls (HCs).
A cognitive task battery, including the Wisconsin Card Test, Span Attention Test, Tower of London, Trail Making Test, Verbal Fluency Test, Matrices Scores and N-Back, was administered to 62 subjects (30 bipolar patients and 32 matched HCs) and differences between the groups analyzed.
Bipolar patients performed significantly worse than HCs in the Span Forward task, in the expression of Verbal Fluency Test (Category) and in the N-Back task (all p<.05), with marginal differences between BD I and BD II patients.
The present study pointed out significant differences in terms of cognitive performance between euthymic bipolar patients and HCs, supporting the notion that specific cognitive functions may remain impaired even after the resolution of the acute episodes in subjects suffering from BD. Future studies on larger samples are warranted to confirm the present results and further explore potential differences in cognitive impairment across specific bipolar subtypes.
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
* Address correspondence to this authors at the Department of Psychiatry, University of Milan, Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, via Francesco Sforza 35, 20122 Milano, Italy, Tel: 02-55035994; Fax: 02-503203100; Email: firstname.lastname@example.org §Equally contributing first authors.