Design, setting and participants: Between May and August 2006, a national computer-assisted telephone survey was conducted on a representative sample of Australian youths aged 12–25 years. 3746 young people and 2005 of their parents were presented with a case vignette portraying psychosis, depression, depression with alcohol misuse, or social phobia in a young person.
Results: Over 85% of participants agreed that alcohol, tobacco and marijuana were harmful for the young people in the vignettes, and over 80% of youths agreed that not using marijuana or drinking alcohol in excess would reduce the risk of developing a similar problem.
Conclusion: Young people and their parents are fully aware of the negative impact of substance use on mental disorders. Translating this knowledge into behavioural change will be a major challenge for future public health campaigns.
Recent research highlighting the links between early onset of substance use and mental health problems later in life has increased public and political concerns about the use of alcohol and illicit drugs by young people.1-4 Teenagers who regularly smoke tobacco appear to be more likely to have mental health problems in later adolescence,5 while early onset of regular cannabis use has been consistently associated with later psychotic symptoms or disorder.4,6 Although few epidemiological studies have found a direct link between early onset of alcohol consumption and the development of anxiety or depressive disorders in young adulthood (after adjusting for other risk factors),7 teenagers who misuse alcohol report higher rates of mental disorders8,9 and attempted suicide.10
Complementing existing drug prevention strategies, the Australian Government has recently launched a campaign specifically aimed at improving community awareness of the link between illicit drugs and the development of mental disorders.11 However, little is known about young people’s knowledge and beliefs regarding the role of licit and illicit substances in the prevention and treatment of mental disorders, or what variables predict their beliefs. Here, we report the first national survey addressing this issue in young people and their parents.
Between May and August 2006, a national computer-assisted telephone survey was conducted on a representative sample of Australian youth. Interviewers ascertained whether any residents in the household were within the age range of 12–25 years and selected one for interview using the nearest-birthday method. If the young person lived with one or more parents, then the parent with the nearest birthday (Kish method of random selection) was also invited to be interviewed.
The interview was based on a case vignette of a young person (John or Jenny) with a mental disorder. On a random basis, respondents were read one of four vignettes — depression, depression with alcohol misuse, social phobia, or psychosis (schizophrenia)12 — portraying a person aged 15 years (for participants aged 12–17 years) or 21 years (for participants aged 18–25 years) of the same sex as the participant. If a parent was interviewed, he or she was read the same vignette as his or her child.
All respondents were then asked a series of questions that assessed sociodemographic characteristics, mental health literacy, stigma, exposure to mental disorders, beliefs about interventions and prevention for the mental disorder in the vignette, psychological distress (using the K6 screening scale13), and exposure to mental health media campaigns. To assess their beliefs about using substances to deal with mental disorders, young people were asked: Do you think the following are likely to be helpful, harmful or neither for John/Jenny? The actions that followed were:
Using alcohol to relax;
Smoking cigarettes to relax;
Using marijuana to relax;
Cutting down on use of alcohol;
Cutting down on smoking cigarettes; and
Cutting down on use of marijuana.
Young people were also asked: If a young person did the following, do you think it would reduce their risk of developing a problem like John’s/Jenny’s? The actions that followed, using a yes, no, depends, don’t know response format, were:
Parents were asked similar questions about what they could do to reduce their child’s risk. A distractor item, “Avoiding sugary foods”, was also included in this section to determine the potential role of demand characteristics within the survey. While there is no supporting evidence that avoiding sugary foods has a role in preventing mental disorders, this item was deemed to have sufficient face validity as a positive health behaviour (given that it is a focus of many health promotion campaigns).
The data were analysed using per cent frequencies with 95% confidence intervals, with the sample divided by age group into “adolescents” (aged 12–17 years) and “young adults” (aged 18–25 years). Logistic regression analyses were performed to determine if age group, sex or psychological distress score were predictors of substance use beliefs among young people.
Of the 6087 youth sample members who met inclusion criteria and could be contacted, 3746 completed interviews (response rate, 61.5%). There were 835 males and 798 females in the adolescent group, and 958 males and 1155 females in the young adult group. Of the 2925 youth respondents with a parent in the household, 2005 parents (68.5%) completed interviews.
Box 1 shows the beliefs of young people and their parents about the use of substances in preventing or dealing with mental disorders. Over 85% of young people and parents agreed that alcohol, marijuana and tobacco were harmful for the young people in the vignettes to use for relaxation, and a similar proportion indicated that it would be helpful for them to cut down on use of these substances. Over 80% of young people also agreed that not using marijuana or drinking alcohol in excess would reduce the risk of developing a problem like the person in the vignette. However, only about half the young people and their parents rated avoiding sugary foods as an important preventive measure.
In terms of predictors of substance use beliefs of young people (Box 2), female participants were two to three times more likely to describe alcohol, tobacco and marijuana use as harmful. Older participants (ie, those aged 18–25 years) were less likely to report the belief that use of these substances, particularly marijuana, is harmful. Importantly, young people with higher levels of psychological distress were also less likely to report alcohol, marijuana and tobacco use as harmful.
Over 85% of youth respondents agreed that alcohol, tobacco and marijuana were harmful for the young people portrayed in the vignettes. In addition, most young people reported that not using marijuana or not drinking excessively would reduce the risk of developing mental health problems like the people in the vignettes. Parents reported similar views to their children.
These findings strongly suggest that young people and their parents are fully aware of the negative impact of substance use on mental disorders, and that neither licit nor illicit substances are appropriate self-help strategies. On one hand, these findings are extremely encouraging, suggesting that health information regarding the link between substance use and mental disorder has 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,14,15 suggesting that this knowledge does not readily translate into behaviour. In fact, these data are consistent with previous substance misuse awareness and education campaigns, where individuals reported being aware of the negative effects of alcohol and drug use, but showed limited evidence of actual behaviour change as a result.7
Despite the encouraging nature of our findings, there are important caveats that need to be considered. First, this type of study is vulnerable to demand characteristics, especially given the extensive media coverage on substance use and mental health over recent years. Thus, the high rates of endorsement for the harmfulness of these substances across all mental health conditions by both young people and their parents may be due to respondents only reporting what they perceived to be the most socially acceptable answers. However, this only occurred for the identified drugs, and was not apparent for the distractor item, suggesting that respondents did not simply endorse every possible healthy option.
Second, although participants uniformly identified the use of all three drugs as mental health risks, this does not necessarily mean that they were well informed about the nature of such risks. Indeed, it may be that participants were aware of the general negative association between substance use and mental health, but were not able to discriminate between the differing patterns of mental health risk associated with each substance. If this is the case, we need to consider whether this general level of community awareness is sufficient, or whether we need to promote greater understanding of the differing mental health risks associated with each substance.
So what lessons can we draw when designing public health campaigns? Our findings suggest that simply raising awareness of the link between substance use and mental disorder in the general population is not sufficient. Young people’s motivation to abstain from or maintain low levels of substance use will depend on their own perceptions of how vulnerable they are to developing mental disorders, as well as the extent to which they believe that not using substances will help them avoid mental disorders.16 Our finding of differential beliefs by sex, age and level of psychological distress regarding the harmfulness of drug use reinforces this notion, and suggests that public health campaigns need to provide clear, credible, evidence-based information that specifically targets different populations (ie, young males v females, adolescents v young adults, high v low levels of psychological functioning).
It is also important to highlight that beliefs about substance use in clinical samples of young people with substance misuse and/or mental disorders may differ from those at the general population level. More comprehensive health information would likely need to be delivered to these groups, given the complexity of co-occurring disorders and the increased likelihood of differential substance effects.
An important requirement of any public health campaign addressing the link between substance use and mental disorder would be to ensure that people with mental illness are not further stigmatised.17 Instead, campaigns should incorporate messages that focus on improving mental health literacy and help-seeking. Health education programs could also help young people identify potential barriers to action (eg, peer pressure), develop and build confidence in preventive strategies (eg, drug refusal skills), and promote positive self-help strategies and coping skills.16,18
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.
1 Frequency (95% CI) of beliefs of young people and their parents about the use of substances and avoiding sugary foods (distractor item) to deal with or prevent mental disorders
2 Odds ratios (P values) from logistic regressions predicting beliefs of young people by sex, age and psychological distress (K6 scale13), for each vignette*
Received 12 December 2006, accepted 5 June 2007
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