Relation between smoking and visual processing in bipolar disorder

Abstract

Background: Although some studies have shown impairments in patients with bipolar disorder (BPD) and in smokers, it is unclear how these two factors work together. Our premise was that chronic smoking affects color discrimination and this is more pronounced in BPD. Objective: Our main purpose was to investigate the influence of smoking and BPD on color discrimination. Methods: Twenty-three smokers and 23 BPD smokers patients, aged 25–45 years old, participated in this study. Color vision testing was performed using the Trivector subtest of the Cambridge Colour Test. Participants’ task was to indicate the pseudoisochromatic stimulus in four directions (up, down, right, and left). Results: It was shown that the smokers had better color vision than BPD smokers for the Protan (p < .001), Deutan (p < .001), and Tritan (p < .001) (red, green, and blue, respectively) axes. Thus, the BPD smokers’ group had greater difficulty distinguishing the chromaticity variations (i.e., presented diffuse color vision impairments and not specific to any axis). Conclusions: The present study highlights a possible relationship between smoking and BPD in color discrimination. This highlights the importance of understanding the diffuse effects of this relationship.

Keywords:

• Bipolar disorder
• smoking
• smokers
• color processing
• visual processing

Authors’ contributions

MCO helped with data interpretation and helped to draft the manuscript. NA performed the experiments, participated in the design of the study and performed the statistical analysis. TF conceived and designed the experiments, participated in its coordination and helped to draft the manuscript. NS conceived and designed the experiments, helped to draft the manuscript and helped with data interpretation. All authors read and approved the final manuscript.

Disclosure statement

The authors declare that they have no competing interests.

Correction Statement

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

Additional information

Funding

The National Council for Scientific and Technological Development (CNPq), Brazil (305258/2019-2), and Coordination for the Improvement of Higher Education Personnel (CAPES) supported this study