52 Internalizing Psychopathology is Highly Related to Subjective Cognitive Impairment and the Discrepancy Between Objective and Subjective Cognitive Impairment: A Preliminary Cross-Sectional Study.

Abstract

Objective:

Eliciting perceived cognitive complaints is a routine part of a clinical neuropsychological evaluation, presumably because complaints are informative of underlying pathology. However, there is no strong empirical support that subjective cognitive impairment (SCI) is actually related to objective cognitive impairment as measured by neurocognitive tests. Instead, internalizing psychopathology is thought to predominately influence the endorsement of SCI. Specifically, individuals with greater symptoms of depression and anxiety, when accounting for comorbidities, have a higher disposition to overestimate their degree of cognitive impairment as compared to objective testing. Yet, there are few existing studies that have determined which factors influence both SCI and the discrepancy between subjective and objective cognitive impairment in general outpatient populations. The current study examined the relationship between subjective and objective cognitive impairment in a clinically diverse sample of outpatients. We additionally explored the associations between SCI and relevant intrapersonal factors including internalizing psychopathology, number of medical comorbidities, and demographics. Finally, we quantified the degree of discrepancy between subjective and objective impairment and examined this discrepancy in relation to the intrapersonal factors.

Participants and Methods:

The sample comprised 142 adult women and men (age range 18–79 years) seen in an outpatient neuropsychology clinic for a diverse range of referral questions. Scores on the cognition portion of the WHO Disability Assessment Schedule (WHODAS 2.0) were used to index SCI. A composite score from 14 measures across various domains of cognitive functioning served as an objective measure of cognitive functioning. Internalizing psychopathology was measured via a standardized composite of scores from screening measures of anxiety and depression. Medical comorbidities were indexed by the number of different ICD diagnostic categories documented in patients' medical records. Demographics included age, sex, race, and years of formal education. Objective-subjective discrepancy scores were computed by saving standardized residuals from a linear regression of neurocognitive test performance on the WHODAS 2.0 scores.

Results:

A hierarchical linear regression revealed that objective cognitive impairment was not significantly related to SCI (p > .05), explaining less than 2% of the variance in SCI ratings. Likewise, participants' demographics (age, sex, education, race) and number of comorbidities were not significantly related to their SCI ratings, explaining about 6% of the variance. However, participants' level of internalizing psychopathology was significantly associated with SCI (F[10, 131] = 4.99, p < .001), and explained approximately 20% of the variance in SCI ratings. Similarly, the degree of discrepancy between subjective and objective cognitive impairment was primarily influenced by internalizing psychopathology (F[9, 132] = 5.20, p < .001, R2 = 21%) and largely unrelated to demographics and number of comorbidities, which explained about 6% of the variance.

Conclusions:

These findings are consistent with prior research suggesting that SCI may be more indicative of the extent of internalizing psychopathology rather than actual cognitive impairment. Taken together, these results illuminate potential treatment and diagnostic implications associated with assessing perceived cognitive complaints during a neuropsychological evaluation.