Experiencing abuse or neglect as a child can cause multiple mental health problems in later life, a first-of-its-kind new study has concluded.
Research was initiated 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 project, the first of its kind, analysed 34 quasi-experimental studies, involving over 54,000 people.
Across the 34 studies, researchers found small effects of child maltreatment on a range of longstanding mental health problems, including internalising disorders – such as depression, anxiety, self-harm, and suicide attempt – externalising disorders like alcohol and drug abuse, ADHD, and conduct problems, as well as psychosis.
These effects were consistent regardless of the method used or way in which maltreatment and mental health were measured.
The findings suggest 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,” said corresponding author Dr Jessie Baldwin, of UCL Psychology & Language Sciences.
“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.”
Nevertheless, the 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, such as socioeconomic disadvantage, and genetic liability.
Dr Baldwin said: “Our findings also suggest that to minimise risk of mental health problems in individuals exposed to maltreatment, clinicians should address not only the maltreatment experience, but also pre-existing psychiatric risk factors.”
Researchers defined childhood maltreatment as any physical, sexual or emotional abuse or neglect before the age of 18.
In the research, quasi-experimental studies were used as they can better establish cause and effect in observational data, by using specialised samples like 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.
