The impact of substance use  on young people’s development
An early start to substance use during adolescence and continued intensive use is believed to interfere with transitional milestones being  reached and developmental tasks being  completed. Spooner and colleagues (2001) point  out that the earlier  a young person becomes involved  in chronic, problematic substance use the greater the developmental impact on cognitive functioning, emotional adjustment, social functioning and the formation of self-concept.

Even so, contemporary evidence-based theories, such as Developmental Systems Theory, recognise plasticity  in the bio-psycho-social processes that underpin human development and emphasise the significance of experience in determining outcomes for young people.

Substance use, particularly when it is ongoing and used  as a coping strategy, will directly  influence the experiences of young people and therefore shape the way their development unfolds. This means  that even in cases where developmental processes have been  disrupted by substance use, these  young people continue to develop, albeit in an atypical  manner.

For example, the development of a young woman who  at 16 has been  involved  in procuring and trafficking substances, is not at school, and has had to fend  for herself, may be accelerated in some  areas and delayed in others. She may have developed the capacity for consequential thinking and have achieved a degree of independence and resourcefulness in advance of other  young people of a similar  age. On the other  hand,  she may have limited  opportunities to develop values,  attitudes and social skills that are in step with  other  young people experiencing a more typical  developmental progression. This can mean  that progress towards key developmental milestones, such as developing a vocational identity, is curtailed and in some  cases they may not be reached. This can lead to further marginalisation, thus entrenching problematic substance-using behaviour and limiting  options for change. In this way the developmental trajectories and lifestyles  of many  young people with  serious  substance use-related problems can become less and less synchronised with  most  other  adolescents.

However, on a positive  note,  there  is evidence to show  that developmental milestones and tasks do not have to be achieved at predetermined times.  Given conducive conditions and experiences, young people who have had substance use problems can change their developmental pathway and become healthy adults.