Dr Zoe Reed, Senior Research Associate in the Tobacco and Alcohol Research Group (TARG) in Bristol's School of Psychological Science and co-author of the paper, said: “Legal consumption of alcohol and tobacco may directly increase the level of illicit drug use. However, the relationships are complex. Consuming one drug does appear to increase the consumption of another, but it may also be the case that people have underlying risk factors which increase their chances of consuming both alcohol and tobacco and illicit drugs.”
The study found evidence for a possible gateway effect between:
- Tobacco use and subsequent alcohol and cannabis use
- Cannabis use and subsequent tobacco use
- Opioid dependence and subsequent alcohol consumption.