A literature review
Results
The most extensive and consistent evidence relates to young people’s interaction with their
families. The key predictors of drug use are parental discipline, family cohesion and parental
monitoring. Some aspects of family structure such as large family size and low parental age
are linked to adolescent drug use. There is also consistent evidence linking peer drug use
and drug availability to adolescent drug use. There is extensive evidence on parental
substance use, although some studies report no association while others indicate that the
association is attenuated by strong family cohesion. Age is strongly associated with
prevalence of drug use among young people reflecting a range of factors including drug
availability, peer relationships and reduced parental monitoring. There is limited evidence
suggesting that genetic factors account for a significant proportion of the variance in liability to
use cannabis, however this interpretation has been criticised by other writers. There is a
similar level of evidence linking self-esteem and hedonism to drug use. The available
evidence indicates that higher levels of drug use are strongly associated with young people’s
reasons for using drugs after controlling for risk factors.
Categories where evidence linking specific factors is mixed include: mental health, Attention
Deficit Hyperactivity Disorder (ADHD), stimulant therapy, religious involvement, sport, health
educator interventions, school performance, early onset of substance use and socioeconomic
status. For some of these categories there is evidence of indirect effects; for
example, socio-economic status may influence parental monitoring which in turn influences
drug use. The review did not consider any studies relating to previously identified risk and
protective factors such as ethnicity or impulsivity.
For young drug users in treatment, psychosocial risk predicts drug abuse at treatment entry
but not follow up. In contrast, protective factors are of increased importance during recovery
The overall ratio of risk to protection may be more important than any individual factor. These
results, although supported by a relatively small body of research, support the concept of
resilience to drug use. According to this view resilience to drug use is enhanced by increasing
social skills, social attachments and material resources despite constant exposure to known
risk factors.
Whereas risk and resilience are, to a large extent, independent of individuals’ motives, there
is evidence that the latter are just as important as the former in determining drug use. Young
drug users consistently report getting intoxicated and relief from negative mood states as
reasons for their drug use. Qualitative research shows that the context in which young people
experience drugs is crucial for understanding how risk and protective factors operate in
relation to experimental and sustained drug use.
Risk factors have differential predictive values throughout adolescence. Some factors may
occur at birth (or before) while others occur at varying times throughout adolescence. Some
factors may persist for long periods of time while others are transitory. The distinction
between early and late onset risk factors is important as preventive measures need to focus
on particular age groups.
Conclusion
This review was pragmatic because it was time constrained and not all the studies identified
could be reviewed in detail. From the studies reviewed, the evidence relating to factors
associated with increased (or decreased) risk of drug use is described. Further analysis would
require a detailed assessment of individual studies, with clear specification of exposures (risk
and protective factors), outcomes (type and level of drug use) and study design (i.e. did
exposure precede the outcome).
Much of the current knowledge about risk and protective factors is not yet available in a form
that would permit the calculation of the effect of reducing exposure to risk (or enhancing
protective factors), even if was possible to modify the exposure. The evidence indicates that
risk and protective factors are context dependent and operate on people taking drugs for
disparate reasons. With these caveats, improving the general social environment of children
and supporting parents will probably be the most effective strategies for primary prevention of
drug use. Studies indicating that risk and resilience can be successfully altered include
interventions for parental monitoring and enhancement of social attachments and skills.
These interventions show promise but have rarely been implemented or evaluated in the UK.

Source:   Home Office OnLine report 05/07 Martin Frisher et al