Childhood sexual abuse linked to schizophrenia risk

MedWire News: Individuals who experience sexual abuse in childhood face an increased risk for developing psychotic disorders in later life, results from an Australian study suggest.

Previous studies have shown that a history of sexual abuse in childhood is associated with an increased incidence of depression, anxiety, substance abuse, post-traumatic disorders, and suicidality in adulthood, explain Paul Mullen (Monash University, Victoria) and team.

But they add: ”The possibility of a link between childhood sexual abuse (CSA) and later psychotic disorders, however, remains unresolved.”

To investigate further, the team studied data on 2759 individuals who were known to have been sexually abused before the age of 16 years between 1964 and 1995 in Victoria, and 2677 age- and gender-matched individuals from the general population (controls).

The researchers used the Victorian Psychiatric Case Register to identify all participants who had lifetime contact with public mental health services and received a psychiatric diagnosis.

They found that the incidence of any psychotic disorder was significantly higher among CSA cases than controls, at 2.8% versus 1.4% (odds ratio [OR]=2.1). Furthermore, 1.9% of CSA cases were diagnosed with schizophrenia compared with just 0.7% of controls (OR=2.6).

The incidence of any psychotic disorder and schizophrenia was even higher among individuals who had been exposed to penetrative abuse, at 3.4% and 2.4%, respectively.

Further analysis revealed that penetrative, but not non-penetrative, sexual abuse was associated with an increased risk for psychotic disorders and schizophrenia, at ORs of 2.6 and 3.3, respectively.

Individuals exposed to abuse that involved penetration, occurred after age 12 years, and involved more than one perpetrator had the greatest risk for any psychotic disorder and schizophrenia, at respective ORs of 14.9 and 12.5.

Mullen and team conclude: ”This study establishes a clear statistical relationship between CSA and an increased rate of psychotic disorders, including schizophrenic syndromes, in later life.”

They add: ”Irrespective of whether this statistical association reflects any causal link, it does identify an at-risk population in need of ongoing support and treatment.”

The research is published in the Archives of General Psychiatry.

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