This study investigates the association between adverse childhood experiences (ACEs) and adult mental health outcomes, adjusting for familial confounding. Using a Swedish twin cohort, the researchers followed 25,252 adult twins from the Swedish Twin Registry over a period of up to 39 years. The study assessed seven types of ACEs, including family violence, emotional abuse, physical neglect, physical abuse, sexual abuse, rape, and hate crime. The primary outcome was the clinical diagnosis of psychiatric disorders in adulthood, such as depression, anxiety, alcohol or drug misuse, and stress-related disorders. Key findings include: - A greater number of ACEs was associated with increased odds of any psychiatric disorder, with each additional ACE increasing the odds by 52%. - The association remained significant after adjusting for familial confounding, particularly in dizygotic (DZ) and monozygotic (MZ) twin pairs. - Individuals exposed to sexual abuse had significantly higher odds of any clinically confirmed psychiatric disorder compared to those not exposed, with odds ratios ranging from 2.10 to 3.09 in DZ and MZ twin pairs. - The attenuation of effect sizes in DZ and MZ twin pairs suggests that familial confounding contributed to the association between ACEs and adult mental health outcomes. The study concludes that interventions targeting ACEs may reduce the risk of future psychopathology, but it also highlights the importance of addressing family-wide risk factors such as genetic predisposition and socioeconomic disadvantages.This study investigates the association between adverse childhood experiences (ACEs) and adult mental health outcomes, adjusting for familial confounding. Using a Swedish twin cohort, the researchers followed 25,252 adult twins from the Swedish Twin Registry over a period of up to 39 years. The study assessed seven types of ACEs, including family violence, emotional abuse, physical neglect, physical abuse, sexual abuse, rape, and hate crime. The primary outcome was the clinical diagnosis of psychiatric disorders in adulthood, such as depression, anxiety, alcohol or drug misuse, and stress-related disorders. Key findings include: - A greater number of ACEs was associated with increased odds of any psychiatric disorder, with each additional ACE increasing the odds by 52%. - The association remained significant after adjusting for familial confounding, particularly in dizygotic (DZ) and monozygotic (MZ) twin pairs. - Individuals exposed to sexual abuse had significantly higher odds of any clinically confirmed psychiatric disorder compared to those not exposed, with odds ratios ranging from 2.10 to 3.09 in DZ and MZ twin pairs. - The attenuation of effect sizes in DZ and MZ twin pairs suggests that familial confounding contributed to the association between ACEs and adult mental health outcomes. The study concludes that interventions targeting ACEs may reduce the risk of future psychopathology, but it also highlights the importance of addressing family-wide risk factors such as genetic predisposition and socioeconomic disadvantages.