Environmental risks for addiction
There's actually been a large amount of research that has sought to identify correlates or risk factors for drug use and for the development of addiction. Many of these studies have compared characteristics of people who use or are addicted to drugs with characteristics of non-users. However, perhaps some of the strongest evidence on factors that might increase risk for addiction come from longitudinal studies that have followed individuals from an early age, perhaps even before drug use has been initiated. They then examine potential risk factors and life processes which may be associated with increased risks for drug use or addiction.
These and other studies have identified a wide range of factors that appear to be associated with increased risks for drug use. These factors span a range of domains, some of which may appear quite distant from the individual, such as laws and societal norms about the use of drugs, socioeconomic status and inequality. It might also include policies about taxation, pricing of tobacco products, or licencing laws such as minimal drinking age for alcohol.
There are more immediate environmental risk factors, like neighbourhood environment and school climate.
In adolescents, one of the strongest correlates of an individual's drug use is the extent to which friends who also use or provide access to drugs.
Family influences have also been shown to be important. These might include parental drug use and also parenting practices.
Finally and most immediately, there are individual factors. These include genetic factors, which I will discuss in depth later, but also personality factors, such as sensation seeking and attitudes to drug use and so forth.
Early initiation of drug use has itself been shown to be a consistent predictor of later risks for addiction.
Combining these different levels of risk factor together, you can see there have been an incredibly large and very diverse range of factors that have been identified as possibly increasing risk for drug use. While scientific research has often tried to isolate the effects of a single risk factor, it is often the case that these factors combine and interact to influence an individual's overall risk for drug problems. It is often the accumulation of risk that determines an individual's overall vulnerability to addiction. Many of those at highest risk for addiction have life stories characterised by exposure to multiple disadvantages, spanning many of the domains I've just mentioned.
Different risk factors may also interact so that their effects on risk are accentuated in the presence of other risk factors. Or they may only increase risks in subsections of the population. Genetic vulnerabilities may interact with specific features of the environment to influence risks for drug use and addiction. However, when considering this literature, it is important to stress that the proposed risk factors are not considered deterministic, but instead increase the probability of drug use often by only a small margin.
For example, while parental alcoholism has been identified as a potent risk factor for the development of alcohol problems, it is still the case that the majority of children of alcoholics will not themselves develop alcohol problems.
There has been growing interest in research examining characteristics of individuals who, despite experiencing various disadvantages, do not develop drug or other problems. Temperamental and intellectual capacities of the individual, as well as features of their immediate environment, including for children a close relationship with an adult role model, have all been shown to protect against the consequences of adverse environments.
While much research has focused on estimating the association between a specific risk factor and risks of developing addiction, the magnitude of this association is only one of several factors that are important. In addition to effect size, it is important to consider how common that risk factor is within the population. Also, some factors may be more difficult to change than others.
there have been a very large number of factors that have been identified as increasing risk for the development of drug use and addiction. These factors span multiple domains that are often themselves correlated so that those most at risk for developing drug problems are exposed to multiple risk factors. Nonetheless, even among those most at risk, there is nothing inevitable about developing drug or other problems.
And increasingly, research has started to identify factors that may be associated with resilience to adversity.