Validity of self-reported concentration and memory problems: Relationship with neuropsychological assessment and depression

BACKGROUND This study investigated the validity of self-reported concentration and memory problems (CMP) in residents environmentally exposed to manganese (Mn). METHOD Self-report of CMP from a health questionnaire (HQ) and the Symptom Checklist-90-Revised (SCL-90-R) was compared to neuropsychological assessment (Trails A&B; Digit Span; Digit Symbol; Similarities; Auditory Consonant Trigrams, ACT; NAB Memory; Rey-Osterrieth, Rey-O, Delayed). Participants included 146 residents from Ohio exposed to air-Mn, with a modeled average concentration of 0.55 µg m-3 (range = 0.01-4.58). RESULTS Residents were primarily White (94.5%), aged 30-64 years (M = 51.24), with a minimum of 10 years of residence (range = 10-64). Ninety-four (65.3%) participants reported concentration problems, and 107 residents (73.3%) reported memory problems. More participants endorsed CMP on the SCL-90-R than on the HQ. The prevalence of self-reported CMP was higher for women than for men (88.4% vs. 68.3%). Point-biserial and Pearson's correlations between self-reported CMP and neuropsychological test scores were nonsignificant and weak for both the HQ (rpb = -.20 to rpb = .04) and the SCL-90-R (r = -.12 to r = .007). Greater levels of depression, anxiety, and female sex predicted having more self-reported CMP on both the HQ and the SCL-90-R. Air-Mn and blood-Mn were not associated with self-reported CMP. Residential distance from the Mn source accounted for a small proportion of variance (sr2 = .04), although depression remained the largest predictor (sr2 = .21). CONCLUSION These results indicate that self-report of CMP in Mn-exposed residents appear to be invalid when compared to neuropsychological test scores. The participants' misperception of having CMP is associated with less education and higher levels of depression. Neuropsychological assessment is recommended to attain valid results.