THE EFFECT OF PSYCHOLOGICAL DISTRESS AND PERSONALITY TRAITS ON COGNITIVE TEST PERFORMANCES AND THE RISK OF DEMENTIA IN PATIENTS WITH MILD COGNITIVE IMPAIRMENT

Abstract

Alzheimer's Disease (AD) dementia and its prodromal stages are characterized by changes in cognition, behavior, and personality. The relation between personality traits, emotional distress, and cognitive test performances, and the predictive accuracy of personality traits and emotional distress for the development of AD dementia in subjects with Mild Cognitive Impairment (MCI) remains unclear. MCI patients (n= 343, age: 60.9±9.9 years, 38% female, and MMSE score: 28.1±1.8) were included from the memory clinic of the Maastricht University Medical Center. All participants underwent a standardized neuropsychological assessment (including tests for measuring information processing speed, executive functioning, memory, and verbal fluency), CT or MRI, and blood assessment. The Dutch Personality Questionnaire (NPV) and the 90-items Symptom Check List (SCL-90) were used to measure personality traits and psychological distress. Two, five, and ten years after baseline, patients were invited to participate in a follow-up assessment. After correction for age, sex, and education, the Psychoneuroticism score of the SCL-90 was associated with (s)lower performances on STROOP part I and Trail Making Test (TMT) part A. In line with this, the subdomain “Inadequacy” of the NPV was associated with slower scores on the TMT part A. At follow-up, 80 (25.2%) subjects had developed dementia. Mean follow-up period was 80.8±41.1 months [11-175]. After adjustment for age, sex, education and MMSE-score, no subdomain of the NPV or SCL-90 was associated with an increased risk for developing dementia. The SCL-90 subscales Somatization, Obsessive-compulsive complaints, Sleeping problems, Psychoneuroticism, and the NPV subscales Dominance and Rigidity were related to a decreased risk of developing dementia. After correction for HDRS score, results remained essentially the same. Emotional distress negatively affected cognitive test performances (related to information processing speed), but was not associated with an increased risk of developing dementia in patients with MCI.