The study, conducted between May and August 2006 among 3,746 young people and 2,005 of their parents by Dr Dan Lubman, Dr Leanne Hides and Professor Anthony Jorm of the ORYGEN Research Centre at The University of Melbourne, is reported in the latest Medical Journal of Australia.
Study participants were presented with case vignettes portraying young people with psychosis (schizophrenia), depression, depression with alcohol misuse, or social phobia.
The authors report that more than 85 per cent of youth respondents agreed that alcohol, tobacco and marijuana were harmful for the young people portrayed.
"In addition, most young people reported that not using marijuana or not drinking excessively would reduce the risk of developing mental health problems like those seen in the people in the vignettes," Dr Lubman says. Participating parents reported views similar to those of their children.
This suggested that young people and their parents were fully aware of the negative impact of substance use on mental disorders, and that neither licit nor illicit substances were appropriate self-help strategies.
These findings are extremely encouraging, suggesting that health information about the link between substance use and mental disorders had been absorbed by young people and their parents.
"On the other hand, such beliefs are in sharp contrast to the high rates of alcohol, tobacco and cannabis use among young people, suggesting that this knowledge does not readily translate into behaviour."
The authors also found some differences in beliefs about the harmfulness of drug use based on the age, sex and level of psychological distress of the respondents. They recommend that public health campaigns should provide clear, evidence-based information specifically targeting different populations (ie, young males v females, adolescents v young adults, high v low levels of psychological functioning).
"Given the clear mismatch between drug use knowledge and behaviour, future research will be essential in determining the effectiveness of public health campaigns in preventing substance misuse and associated mental disorders in young people, as well as their impact on stigmatisation and help-seeking behaviour."
The Medical Journal of Australia is a publication of the Australian Medical Association.