Key Points: Question: Is a history of childhood maltreatment associated with an unfavorable course of emotional disorders in adulthood? Findings: In this cohort study of 1196 participants followed up to age 40 years, the subjective experience of childhood maltreatment measured through retrospective self-report at age 29 years was associated with the number of subsequent follow-up phases with depression or anxiety, whereas the objective experience measured through official court records was not. Current and lifetime psychopathology at the time the subjective experience was assessed explained its association with the later course of emotional disorders in participants who did not have objective measures of maltreatment but not in those who did. Meaning: The findings suggest that modification of the subjective experience of childhood maltreatment may improve the longitudinal course of emotional disorders. This cohort study examined the relative associations of objective and subjective experiences of childhood maltreatment with the course of emotional disorders in adulthood. Importance: A history of childhood maltreatment is associated with an unfavorable course of illness for emotional disorders. However, the origins and mechanisms underlying these associations are unknown. Objective: To examine the relative associations of objective and subjective measures of childhood maltreatment and continuity in psychopathology with the course of emotional disorders in adulthood. Design, Setting, and Participants: This prospective cohort study followed up until age 40 years participants residing in a metropolitan county of the US Midwest with substantiated records of childhood physical and sexual abuse and/or neglect between 1967 and 1971 and a demographically matched group of participants experiencing no abuse or neglect in childhood. The collected data were analyzed between October 2021 and April 2022. Exposures: The objective experience of childhood maltreatment before age 12 years was prospectively measured through official court records, whereas the subjective experience was measured through retrospective self-report at a mean (SD) age of 29 (3.8) years. Current and previous lifetime psychopathology was also assessed at a mean age of 29 (3.8) years. Main Outcomes and Measures: Symptoms of depression and anxiety were measured at mean (SD) ages of 39.5 (3.5) and 41.2 (3.5) years using Poisson regression models. Results: In a cohort of 1196 participants (582 [48.7%] female and 614 [51.3%] male) followed up to age 40 years, those with objective plus subjective measures of childhood maltreatment had a greater number of subsequent follow-up phases with depression or anxiety than controls (depression: incidence rate ratio [IRR], 2.28 [95% CI, 1.65-3.15]; anxiety: IRR, 2.30 [95% CI, 1.54-3.42]), as did those with subjective-only measures (depression: IRR, 1.49 [95% CI, 1.02-2.18]; anxiety: IRR, 1.58 [95% CI, 0.99-2.52]). In contrast, participants with objective-only measures did not have a greater number of follow-up phases with depression or anxiety (depression: IRR, 1.37 [95% CI, 0.89-2.11]; anxiety: IRR, 1.40 [95% CI, 0.84-2.31]). Current and lifetime psychopathology measured at the time the subjective experience was assessed explained its association with a later course of emotional disorders in participants with subjective-only measures but not in those with objective plus subjective measures. Conclusions and Relevance: In this cohort study, the associations seen between childhood maltreatment and poor course of emotional disorders over the subsequent decade were largely attributable to the subjective experience of maltreatment, which was partly explained by continuity in psychopathology. Modification of the subjective experience of childhood maltreatment could improve the longitudinal course of emotional disorders. [ABSTRACT FROM AUTHOR]