A majority of Australians would seek testing to establish their genetic susceptibility to depression, despite social stigma and questions about the tests validity, a national study has found.
The study, conducted by researchers at the University of New South Wales (UNSW) and published this week in the advance online edition of the UK-based journal Psychological Medicine, is the first population-wide analysis of attitudes toward genetic testing for mental illness.
The randomised phone survey of more than 1,000 Australian adults found strong community acceptance of the testing, especially if provided by a doctor.
The main drivers of interest in seeking genetic testing for depression risk were a personal history of depression and a self-assessment of being at higher-than-average risk, the study found.
The findings are surprising given that we also found widespread belief that genetic links to mental illness would increase rather than decrease stigma and also because the validity and utility of the testing is still in question, said study lead-author Dr. Alex Wilde, from UNSWs School of Psychiatry.
There is no certainty depression will manifest in someone with a higher-than-average risk whether they are exposed to stressful life events or not. The results reflect a prevailing belief that the benefits of knowing ones own genetic susceptibility outweigh the risks, she said.
The most frequently endorsed benefit was the belief that testing could facilitate prevention and early intervention of a major depressive disorder.
The most endorsed disadvantage was the fear that insurance companies or employers would discriminate against people who returned a positive result.
Significantly, there was a much greater interest in seeking genetic tests for depression risk through a doctor (63%) compared to direct-to-consumer (40%), although interest in direct-to-consumer genetic testing persisted.
The topic of genetic testing for common disorders has been subject to continuing interest all over the world since the rise, fall, and rise again of the unregulated direct-to-consumer genetic testing market, Dr. Wilde said.
This is especially so given the lack of genetic non-discrimination laws in Australia and inadequacy of such laws in Europe and the USA.
Many genetic tests currently offered direct-to-consumer involve unreplicated gene-disease associations and have uncertain predictive value and clinical utility, Dr. Wilde said.
While several governments have issued a ban on marketing genetic tests for common complex disorders directly to consumers in the absence of appropriate regulations, the tests are freely available online.
Considering direct-to-consumer genetic tests are marketed internationally, consumers may have no legal protection from genetic discrimination for insurance or employment in their own country, Dr. Wilde said.
These findings highlight that while any future genetic susceptibility testing for depression risk as an intervention tool for target groups is likely to be acceptable to the general community, they indicate the need for appropriate legislation to prevent genetic discrimination. There is also a need for further research to see how information about genetic susceptibility might be best used in health care.
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