“Gateway Drug Theory:” The Experience/Contribution Coming from the Service for Pathological Dependencies of Parma (Italy)

Background: “Gateway Drugs Theory” indicates the assumption that the use of an illicit drug or psychoactive substance may be associated with a greater likelihood of switching to using more harmful substances. Materials and Methods: With reference to this theory, the objective of this study is to understand how many of the subjects that referred to the Service for Pathological Dependencies (SerDP) of Parma, from 2016 to 2019, and who kicked off their addiction to cannabis, have then switched to the use of different drugs, by analysing all the information obtained from the patients and their health life archive. Results: The total number of patients considered was 160 (142 males and 18 females). 35 out of 160 subjects (21.9%) manifested the switch, i.e. a substance "escalation" that induced the subject to being using cannabis as another drug. 60% of the patients (21/ 35), after an average of 2 years of cannabis use, started abusing cocaine too. Among them, moreover, few particular cases arose, namely 4, in which simultaneous positivity also resulted for other substances. It turns out that 17 patients (48.6%) out of 35 experienced the switch towards cocaine, while 4 patients (11.4%) manifested a switch to more than one substance. Considering the passage to opiates, 9 patients were identified (25.7%). 5 patients all switched to amphetamine (14.3%). Conclusions: The theory of cannabis as a gateway drug should be associated with the theory of vulnerability according to which some people, due to genetic, individual and environmental characteristics, are more exposed at the risk of developing addiction if placed in contact with drugs.