Colour vision in ADHD: part 1--testing the retinal dopaminergic hypothesis

Area of Science:

• Neuroscience
• Ophthalmology
• Psychology

Background:

• The retinal dopaminergic hypothesis suggests ADHD involves reduced dopamine, affecting color perception, particularly blue, to which blue cones are sensitive.
• Investigating sex differences in color perception within ADHD is crucial for understanding visual processing variations.

Purpose of the Study:

• To evaluate the retinal dopaminergic hypothesis in ADHD by testing blue and red color perception.
• To explore sex-specific differences in color perception among individuals with and without ADHD.

Main Methods:

• A psychophysical task assessed blue and red color saturation and contrast discrimination in 30 adults with ADHD and 30 controls.
• Visual function questionnaires (VAQ) and color vision tests (Farnsworth-Munsell 100 hue test) were administered.

Main Results:

• Females with ADHD showed impaired discrimination of blue and red color saturation compared to controls.
• While females typically outperform males in red saturation discrimination, this sex difference was absent in the ADHD group.
• No significant differences in contrast sensitivity were observed between groups.

Conclusions:

• Impaired red and blue color saturation discrimination in females with ADHD may stem from retinal hypodopaminergic states affecting early visual processing.
• The typical female advantage in red perception may be linked to evolutionary factors, and its absence in ADHD warrants further research.
• These findings highlight potential visual processing differences in ADHD, particularly in females, linked to dopamine pathways.