This paper draws on the reservoir of data collected under the National Household Survey of Drug Abuse (NHSDA) over more than 25 years. The author makes a particular study of the use of cannabis and correlates this with self reported behaviours from young people (12- ‘years old general] From within her paper, extracts are given which relate to aggressive behaviour and to criminal behaviour. The romantic view of cannabis is that it mellows people out and is not associated with aggression; assertions are also made that cannabis users are not generally associated with criminal behaviour. These extracts give die lie to both these assertions.

Aggressive behaviour:

Past year cannabis users were more likely than non-users to report all types of aggressive behaviour. For many items, the percentage reporting the behaviour increased as frequency of use of cannabis increased. Weekly users were nearly four times as likely as “on-use’s to report they physically attacked people (26% v 7%) and three times as likely to report they destroy things that belong to others (22% v 7%). they threaten to hurt people (38% v 3%).and the get in many fights (37% v 14%). The weekly users are also twice as likely as non-users to report they disobey at school (59% v 24%) and they destroy their own things (22% v 10%). On average, past year cannabis users, regardless of frequency of use. were twice as likely as non-users to report they destroy things that belong to others, they disobey at school, they get in many fights, and they threaten to hurt people.

Criminal behaviour

In addition to the YSR (Youth Self-Report) Module, the NHSDA included questions about some past-year activities that may have been illegal. In each criminal behaviour compared in this study, adolescents aged 12 to 17 who used cannabis in the past year were three to more times more likely than non-users to report past-year involvement in these activities. Past-year cannabis users were more likely than non-users to reports that in the past year, they were on probation, they had taken something from the store without paying, purposely damaged property that was not theirs, driven under the influence of alcohol or drugs, hurt someone enough to need a bandage, and sold illegal drugs. As before, in most cases, the percentage reporting these behavioural problems increased with the frequency of cannabis use. In particular, weekly users of cannabis were more than five times as likely as those who used only 1-1 I times in the past year to have driven under the influence of drugs (29% v 4%) or to have so illegal drugs in the past year (29% v 6%). Weekly users were also two-to-three times more likely than those who use less often than monthly to be on probation (20% v 7%), to have driven under the influence of alcohol (20% v 9%), or to have purposely damaged property that was not theirs (35% v 18%).
As Greenblatt says in her conclusions, this analysis shows that amongst those aged 12 to 17, cannabis users were more likely than non-users to report problem behaviours. Further, the more frequent the use, the more likely the reporting of problem behaviours. A further worry is that cannabis-using young people were more likely to report behaviours symptomatic of anxiety and depression, including thoughts of suicide. These findings strengthen the argument that cannabis is not a benign substance.