Experiencing abuse and neglect can cause multiple mental health issues UCL finds

Experiencing abuse or neglect as a child can cause multiple mental health problems, a new study led by University College London (UCL) researchers has found.

Published in the American Journal of Psychiatry, the study sought to examine the causal effects of childhood maltreatment on mental health by accounting for other genetic and environmental risk factors, such as a family history of mental illness and socioeconomic disadvantage.

The first-of-its-kind research analysed 34 quasi-experimental studies, involving over 54,000 people. 

Quasi-experimental studies can better establish cause and effect in observational data, by using specialised samples (e.g. identical twins) or innovative statistical techniques to rule out other risk factors. For example, in samples of identical twins, if a maltreated twin has mental health problems but their non-maltreated twin does not, the association cannot be due to genetics or the family environment shared between twins.

Using 34 different studies the researchers found small effects of child maltreatment on a range of mental health problems, including internalising disorders (e.g. depression, anxiety, self-harm, and suicide attempt), externalising disorders (e.g. alcohol and drug abuse, ADHD, and conduct problems), and psychosis.

These effects were consistent regardless of the method used or way in which maltreatment and mental health were measured, with findings suggesting that preventing eight cases of child maltreatment would prevent one person from developing mental health problems.

“It is well known that child maltreatment is associated with mental health problems, but it was unclear whether this relationship is causal, or is better explained by other risk factors,” corresponding author Dr Jessie Baldwin explained.

“This study provides rigorous evidence to suggest that childhood maltreatment has small causal effects on mental health problems. Although small, these effects of maltreatment could have far-reaching consequences, given that mental health problems predict a range of poor outcomes, such as unemployment, physical health problems and early mortality.”

“Interventions that prevent maltreatment are therefore not only essential for child welfare, but could also prevent long-term suffering and financial costs due to mental illness.”

Researchers also found that part of the overall risk of mental health problems in individuals exposed to maltreatment was due to pre-existing vulnerabilities – which might include other adverse environments (eg. socioeconomic disadvantage) and genetic liability.

To minimise the risk of mental health problems in individuals exposed to maltreatment, the researchers said, clinicians should address not only the maltreatment experience, but also pre-existing psychiatric risk factors.

Access the full study here.