Anhedonia Relates to Increased Psychomotor Retardation Using an Instrumental Handwriting-Based Measure

Area of Science:

• Neuroscience
• Psychiatry
• Behavioral Science

Background:

• Psychomotor retardation (PmR) is a significant but under-researched aspect of depression.
• Current assessment methods for PmR in depression rely on subjective self-report and observation, lacking precision.
• Instrumental measures offer greater sensitivity for motor symptoms, similar to their use in neurological disorders.

Purpose of the Study:

• To investigate the association between depression and velocity scaling (VS), an instrumental measure of PmR.
• To assess the reliability of VS as a measure of psychomotor function.
• To explore the relationship between VS and anhedonia in individuals with and without Major Depressive Disorder (MDD).

Main Methods:

• A handwriting task using a tablet was administered to healthy controls (n=85) and individuals with lifetime MDD (n=146).
• Velocity scaling (VS) was quantified by analyzing the slope of velocity change during hand-drawn loops (1-4 cm).
• Internal consistency of VS scores was evaluated.

Main Results:

• No significant difference in VS was found between healthy controls and individuals with MDD.
• Lower VS scores were significantly and negatively correlated with higher levels of anhedonia, independent of overall depression severity.
• VS demonstrated excellent internal consistency, indicating high reliability.

Conclusions:

• Handwriting analysis provides a reliable and brief instrumental measure for assessing psychomotor retardation (PmR).
• Velocity scaling (VS) shows a significant negative correlation with anhedonia in depression.
• This handwriting-based approach may offer a feasible method for evaluating PmR in clinical settings, warranting further research into its temporal relationship with anhedonia.