Second to fourth digit ratio and cognitive functioning in bipolar disorder.

Area of Science:

• Neuroscience
• Psychiatry
• Endocrinology

Background:

• Bipolar disorder (BD) presents complex mood, neuropsychological, immunological, and physiological alterations.
• Cognitive impairments in BD patients often persist even during periods of remission.
• The second-to-fourth digit ratio (2D:4D) is a potential marker of prenatal androgen exposure and has been linked to various neurodevelopmental conditions.

Purpose of the Study:

• To investigate the relationship between the second-to-fourth digit ratio (2D:4D) and cognitive functions in patients with Bipolar Disorder (BD).
• To compare 2D:4D ratios and cognitive performance between BD patients in remission and healthy controls.

Main Methods:

• A cross-sectional study involving 47 BD patients in remission and 47 healthy volunteers.
• Cognitive functions assessed using the Stroop Test (ST), Wisconsin Card Sorting Test (WCST), and Trail Making Test A and B (TMT-A/B).
• The 2D:4D ratio was measured using a digital caliper by a single researcher for consistency.

Main Results:

• BD patients exhibited a significantly higher left 2D:4D ratio compared to healthy controls.
• Significant differences in ST, WCST, and TMT-A/B scores were observed, with BD patients performing worse.
• A weak negative correlation was found between TMT-A completion time and right-hand 2D:4D in the BD group.

Conclusions:

• The study reveals distinct differences in 2D:4D ratios between BD patients and healthy individuals.
• Cognitive functions in BD patients remain impaired even during remission, suggesting long-term neurobiological changes.
• 2D:4D ratio may serve as a potential biomarker for cognitive alterations in Bipolar Disorder.