STAGE 4. Selecting the theoretical approach

What steps should be completed?

Step 1: Select the theoretical approach or approaches on which the intervention will be based


What are its bases?

Its basic premise is that problematic drug use does not occur suddenly, but develops through an evolutionary process in which the use of certain drugs precedes the use of others. It starts with alcohol and tobacco (which act as initiation substances and facilitate subsequent use of other substances), followed by cannabis derivatives and then other illegal drugs. Using a substance in one stage increases the likelihood of moving to the next stage of use, although it does not imply that this will necessarily occur.

The model (approach) establishes that imitating the behaviours of other significant people, and the social reinforcement that adolescents receive from these people, determines the initiation and maintenance of drug use. It also identifies four types of factor that predict use: family variables, peer group variables, intraindividual factors and involvement in deviant activities. These factors have different effects at different stages of use: social factors would be more important in the early stages of use, while psychological factors gain more weight in later stages. Family and peer group are two of the basic influences that are related to drug use (or non-use).

Which determinants can be addressed?

The main determinants of this model (approach) are personal (such as the age of initiating drug use, personal attitudes favourable to drug use and involvement in socially deviant activities) and social (such as relationships with peers who use drugs, drug use in the family environment and the quality of relationships with parents).

Practical implications

A practical implication of this model (approach) is that prevention should aim to delay the age of drug use initiation, as the earlier the initiation, the more likely it is that problematic patterns of drug use will occur. Preventing the use of legal drugs is also a priority, as it also helps prevent progression to illegal drugs.



Kandel DB. (1975). Stages in adolescent involvement in drug use. Science. 190: 912-914.