Childhood maltreatment and joint trajectories of social isolation and depression as predictors of cognitive impairment in late midlife: a prospective cohort study

Abstract

Abstract Aims Childhood maltreatment has been associated with increased risk of cognitive impairment in later life, but little is known about whether distinct joint trajectories of social isolation and depression across midlife predict this risk. Methods Using a prospective cohort design with documented childhood maltreatment and matched controls (N = 1196) followed from ages 0 to 11 into late midlife, we modelled joint trajectories of social isolation and depression (ages 29–47) using group-based trajectory modelling (GBTM) and examined their associations with cognitive impairment with no dementia (CIND) at age 59 through modified Poisson regression, controlling for risk factors related to neurodegenerative outcomes (i.e., hypertension, diabetes, obesity, limited physical activity, hearing impairment, smoking, excessive alcohol consumption and traumatic brain injury). Results GBTM identified four groups: ‘Not isolated or depressed’ (67.7%), ‘Moderately isolated’ (11.7%), ‘Moderately depressed’ (16.5%) and ‘Chronically isolated and depressed’ (4.1%). Using the ‘Not isolated or depressed’ group as the reference category, membership in the highest-risk trajectory (‘Chronically isolated and depressed’) was associated with a 41.5% higher risk of CIND, whereas the ‘Moderately isolated’ and ‘Moderately depressed’ groups did not differ significantly from the reference group. Black non-Hispanic participants and those with documented childhood maltreatment histories had 32.8% and 21.2% higher risk of CIND, respectively, and each additional year of education was associated with a 4.9% reduction in CIND risk. Conclusions Sustained co-occurring social isolation and depression from early to mid-adulthood predicted increased risk of CIND independent of established risk factors, highlighting prolonged social and emotional difficulties as modifiable targets for late midlife cognitive health.