An Initial Study of Alexithymia and Its Relationship With Cognitive Abilities Among Mild Cognitive Impairment, Mild Alzheimer's Disease, and Healthy Volunteers

The present study examined the degree to which alexithymia isgreater in mild Alzheimer's disease (AD) and mild cognitive impairment (MCI)relative to healthy volunteers (healthy comparison [HC]), and investigated relationshipsbetween alexithymia and cognition. Eighty-five participants (MCI =30, AD = 21, HC = 34) underwent a comprehensive neuropsychological examinationand completed the 20-item Toronto Alexithymia Scale (TAS-20). Relativeto HC, MCI and AD reported greater alexithymia total scores and higher scoreson the TAS factor difficulty in identifying feelings (DIF). The remaining two factors,difficulty in describing feelings (DDF) and externally oriented thinkingshowed no significant group differences. In MCI, TAS-20 and DIF were negativelycorrelated with working and long-term verbal memory. In AD, TAS-20was negatively correlated with general cognition, attention, memory, and visualspatial constructive and executive abilities. Also in AD, DIF was negatively correlatedwith general cognition, memory, and executive abilities. The correlationbetween DIF and long-term verbal memory in bothMCI and AD suggests a potentialcommon mechanism for alexithymia in these neurocognitive disorders. Declinesin verbal memory may hinder a patient's ability to recall an associationbetween a given sensation and the episodic experience of that sensation, thus leadingto difficulty identifying feelings, as measured by the DIF factor of the TAS-20.