Introduction: Roughly 4% to 23% of the population embody stress prone personality and other traits characterizing a subclinical "broad autism phenotype" (BAP). Subjective cognitive impairment (SCI) among healthy elderly is associated with psychological distress leading us to predict BAP would be associated with SCI.
Methods: The Autism Spectrum Quotient, a self-administered 50 item questionnaire, was completed by 419 consecutive members of the Arizona APOE Cohort who underwent neuropsychological testing every 2 years. SCI was assessed with self and informant versions of the Multidimensional Assessment of Neurodegenerative Symptoms (MANS) Questionnaire.
Results: A total of 45 individuals scored in the BAP range, designated BAP+, and the rest were BAP-. At entry, both Multidimensional Assessment of Neurodegenerative Symptoms Questionnaire Self and Informant scores were higher in the BAP+ group (P<0.0001). After age 60, the BAP+ group had greater annual increases in Multidimensional Assessment of Neurodegenerative Symptoms Questionnaire Self scores (0.05 vs. 0.02; difference=0.03; 95% confidence interval, 0.004-0.05; P=0.02) yet there was no difference between groups in memory decline. Over ~10 years 33 individuals developed mild cognitive impairment: 4 in the BAP+ group (8.9%) and 29 in the BAP- group (7.8%), P=0.77.
Discussion: Individuals who meet criteria for the BAP have escalating SCI with age, but no greater rate of memory decline or clinical progression to mild cognitive impairment.