The key research
Panorama’s “Cannabis: what teenagers need to know” explored the latest scientific research on the effects of cannabis on the human mind. In particular, the growing evidence of links between cannabis and psychotic illness in young people. What follows is a guide to the main theories and research in this field. Four hypotheses have been proposed about the relationship between cannabis use and mental health:
The first, the causal hypothesis, suggests that heavy cannabis use can cause mental disorders such as psychosis.
Second, the dormant hypothesis argues that cannabis use may precipitate a mental disorder that was previously dormant in individuals prone to mental health disorders.
Third, the common cause hypothesis states that mental illness and cannabis use may simply occur together as a result of common variables, such as unemployment, family difficulties and other drug use.
The fourth is the self-medication hypothesis, that people use cannabis after experiencing signs of a mental health disorder in order to alleviate symptoms.
Until recently the consensus amongst the scientific community was that the fourth hypothesis which stated that people suffering from psychosis or schizophrenia used cannabis to alleviate some of the symptoms they were experiencing was the most likely explanation.
However the new research is generating more interest in the first hypothesis; namely that cannabis use itself can cause psychosis. This research is based on studies where large numbers of people are followed through a process of questionnaires over ten to twenty years. The conclusions drawn from these statistical analyses have shown that there is an association between cannabis use by adolescents who are predisposed to mental health problems and later mental health problems.
Read more: www.news.bbc.co.uk
