People commonly report that daily or frequent use over a period of months or even daily use over a period of weeks is enough to establish dependency on some substances. There are claims, sometimes from people with a dependency, but usually in the media that people can be ‘hooked’ the first time they use a substance. There is no evidence for this.

There is also widespread mention of certain substances as being ‘highly addictive’ or state- ments like ‘methadone is more addictive than heroin’. The evidence for the notion of different levels of ‘addictiveness’ is limited. The intrinsic ‘addictiveness’ of a substance, if it exists, seems far less important a factor than the person (see adverse childhood experiences; see trauma; see poverty) and the situation they are in (see drug, set and setting ; see Vietnam veteran studies; see Rat Park)

Factors that may affect how easy it is to develop or overcome a dependency may include

  • availability of a substance
  • acceptability of the substance within your social group
  • peer pressure and role models
  • relationships with people who do not use / people who use
  • having control over your life, opportunity and choice
  • having alternative things to do and motivation to do these things
  • past experience of trauma
  • experience of mental health problems
  • experience of physical health problems
  • current ability to focus on future
  • current ability to prioritise long term health and other issues