This paper reports on a research study examining the relationship between childhood maltreatment and cognitive deficits, including lower IQ and impairment of specific functions; the paper lays out the research methodology and findings, noting that participants with objective measures of childhood maltreatment showed pervasive cognitive deficits in general verbal intelligence, nonverbal intelligence, executive function, and processing speed compared to those individuals without objective measures of childhood maltreatment.
Cognitive deficits might contribute to the elevated risk of life-course psychopathology observed in maltreated children. Leading theories about the links between childhood maltreatment and cognitive deficits focus on documented exposures (objective experience), but empirical research has largely relied on retrospective self-reports of these experiences (subjective experience), and the two measures identify largely non-overlapping groups. The authors aimed to test the associations of objective and subjective measures of maltreatment with cognitive abilities within the same individuals. They studied a cohort of individuals from the US Midwest with both objective, court-documented evidence of childhood maltreatment and subjective self-reports of individuals’ histories at age 29 years. Between the ages of 29 years and 41 years, participants were assessed with a comprehensive set of cognitive tests, including tests of general verbal intelligence (Quick Test and Wide Range Achievement Test-Revised [WRAT]), non-verbal intelligence (Matrix Reasoning Test [MRT]), executive function (Stroop Test and Trail Making Test Part B [TMT-B]), and processing speed (Trail Making Test Part A [TMT-A]). Participants were also assessed for psychopathology (Center for Epidemiologic Studies Depression Scale and Beck Anxiety Inventory). The authors tested the associations between objective or subjective measures of childhood maltreatment with cognitive functions using ordinary least squares regression. To test whether cognitive deficits could explain previously described associations between different measures of maltreatment and subsequent psychopathology, they re-ran the analyses accounting for group differences in the Quick Test. People with lived experience were not involved in the research or writing process. The cohort included 1196 individuals who were assessed between 1989 and 2005. Of the 1179 participants with available data, 173 had objective-only measures of childhood maltreatment, 492 had objective and subjective measures, 252 had subjective-only measures, and 262 had no measures of childhood maltreatment. Participants with objective measures of childhood maltreatment showed pervasive cognitive deficits compared with those without objective measures. The associations with cognitive deficits were specific to objective measures of neglect. In contrast, participants with subjective measures of childhood maltreatment did not differ from those without subjective measures. Furthermore, cognitive deficits did not explain associations between different measures of maltreatment and subsequent psychopathology. Previous studies based on retrospective reports of childhood maltreatment have probably grossly underestimated the extent of cognitive deficits in individuals with documented experiences of childhood maltreatment, particularly neglect. Psychopathology associated with maltreatment is unlikely to emerge because of cognitive deficits, but might instead be driven by individual appraisals, autobiographical memories, and associated schemas. (Published Abstract Provided)