Schizophrenia linked to environmental causes
A New Zealand court case about the relationship of sexual abuse to the development of schizophrenia has potential for alternative understandings around causes of mental illness to be considered in legal contexts.
That’s the conclusion from a study by researchers at the Centre for Mental Health Research at the University of Auckland of a case SL versus the Accident Compensation Commission in 2013.
In a paper, published this week in the journal of Psychiatry, Psychology and Law, the authors Katey Thom and Tony O’Brien looked at the implications of the case for the role of expert witnesses and the balancing of expert opinions in decisions on medical issues. They also discussed the impact on future ACC decisions in New Zealand.
“The case has the potential to be influential in future ACC decisions in New Zealand by setting a precedent for non-biological determinism when considering the causes of mental disorders, says Dr O’Brien from the University of Auckland’s School of Nursing.
“The decision could also have an impact on the low numbers of sensitive claims for independent allowance currently approved by ACC in New Zealand,” he says. “Overall, the case draws attention to the growing acceptance of the evidence that associates the development of mental illness with environmental factors, such as childhood sexual abuse.”
“The legal system in this case, has created a new benchmark for the recognition of one such factor, childhood sexual abuse, in the development of the most troubling of all mental illnesses, schizophrenia.”
He says the medical concept of ‘schizophrenia’ is historically a contested category within health and social care.
“It’s a concept understood by some to be an illness of biological origin, and by others, as a stigmatising label for a sometimes troubling pattern of experiences and behaviours,” says Dr O’Brien.
“Despite this, schizophrenia is firmly embedded in psychiatry. Seen as an ‘illness’, schizophrenia invites theorising and speculation about possible causes,” he says. “Despite decades of research, no causal mechanism of schizophrenia has been clearly identified.”
“In recent years, an accumulating body of evidence has shown a strong association between personal experience of trauma and later diagnosis of schizophrenia,” says Dr O’Brien.
In the summing up in the case (SL vs ACC) Judge Powell analysed two central issues: whether medical science recognises that a causal link exists between sexual abuse and schizophrenia; and whether based on the facts of the case, such a link could be made.
“Judge Powell emphasised that legal decisions regarding causation while drawing on facts supported by expert evidence are not synonymous with scientific understandings of causation,” says Dr O’Brien.
“Instead Judge Powell explained that judges ground their assessment of causation on their view of what constitutes the normal course of events which should be based on the whole of the lay, medical and statistical evidence and not limited to expert witness evidence,” he says. “The result is that legal decisions may infer causation in instances where an expert witness would not.”
Judge Powell rejected the evidence of two expert witnesses in this case while accepting the evidence of a third assessment done for the Court of Appeal.
The outcome of the District Court Appeal was that SL’s appeal was allowed and he was given the entitlements covered by his sensitive ACC claim.