A biomarker and endophenotype for anorexia nervosa?

Area of Science:

• Neuroscience
• Psychiatry
• Genetics

Background:

• Anorexia nervosa (AN) is a complex psychiatric disorder with significant morbidity and mortality.
• Atypical eye movements, specifically square wave jerks (SWJs), have been proposed as a potential biomarker and endophenotype for AN.
• Anxiety is a common comorbidity in AN and may also play a role in its presentation.

Purpose of the Study:

• To investigate the presence of SWJs and anxiety as potential markers in individuals with current AN compared to healthy controls.
• To determine if SWJs are state-independent and heritable by examining individuals who are weight-restored from AN and their first-degree relatives (sisters).

Main Methods:

• The study included 80 female participants across four groups: current AN, weight-restored AN, sisters of individuals with AN, and healthy controls.
• Square wave jerk (SWJ) rate was measured during a fixation task.
• Anxiety levels were assessed using the State Trait Anxiety Inventory.

Main Results:

• All three groups (current AN, weight-restored AN, sisters) exhibited significantly higher SWJ rates than healthy controls.
• SWJ rate and anxiety effectively discriminated between groups, with high accuracy (e.g., 92.5% for current AN vs. healthy controls).
• The findings indicate that SWJs are present regardless of weight restoration and in relatives, suggesting a potential heritable component.

Conclusions:

• The combination of SWJ rate and anxiety presents a promising two-element marker for anorexia nervosa.
• This marker has the potential to serve as a biomarker or endophenotype for identifying individuals at risk of AN.
• These findings could inform the development of novel diagnostic tools and therapeutic strategies for AN.