S. Bacciardi1,2, A.G.I. Maremmani1,2, E. Butelman2, B. Ray2, E. Ducat2, M.J. Kreek2. 1“VP Dole” Dual Diagnosis Unit, Santa Chiara University Hospital of Pisa, Italy; 2Laboratory of the Biology of Addictive Diseases, The Rockefeller University, United States
Background. Age of the first use can be an important variable in the trajectory of addiction. We decided to systematically compare age of first use between consecutively ascertained subjects with and without a history of drug abuse or dependence diagnosis.
Method. We re-valuated 617 subjects consecutively ascertained in the Laboratory of the Biology of Addictive Diseases at the Rockefeller University between April 2002 and May 2005. SCID-I/P criteria were used to define diagnosis of substances dependence, while the Kreek-McHugh-Schluger-Kellogg (KMSK) scale, a relatively rapid and quantitative scale, was used to obtain specific information about drug dependence histories, such as the age of first use. We then compared 140 Normal Volunteers (without any substance use diagnosis according to SCID criteria) and 477 persons with one or more substance abuse or dependence diagnosis (according to SCID criteria), by age of first use.
Results. The Normal volunteers in this cohort had no reported experimentation with heroin, amphetamines, illicit opiates, benzodiazepines or barbiturates. The mean age of first use (expressed in years old) for persons with abuse/dependence diagnoses and normal volunteers was respectively 14 Vs 17 for alcohol (T=.720, p<0.001); 15 Vs 18 for cannabis (T=.388, p<0.004) and 15 Vs 20 for tobacco (T=.017, p<0.001). No differences in age of first use were found with respect to cocaine, between persons with abuse/dependence diagnoses and normal volunteers: 21 Vs 23, respectively (T=-.764, p=.445).
Conclusion. Age of first use (initial experimentation) appears to be an important factor in the clinical trajectory of drug abuse or dependence for specific substances. Thus, experimentation in subjects in their teens is associated with greater long-term vulnerability, for specific drugs. Therefore, prevention and management strategies should address subjects before their adolescence, specifically before 13 years of age. Funding by the Dr. Miriam Adelson and Sheldon Adelson Medical Research Foundation and by NIH-NIDA is kindly acknowledged.