Although adolescents entering treatment for substance abuse typically use s
everal substances. alcohol is seldom the drug of choice. Given alcohol's ro
le as a gateway substance in the initiation of substance misuse, the author
s hypothesize that alcohol is substantially involved in adolescent relapse
following substance abuse treatment. One hundred fifty-seven youths (39.5%
female, mean age 15.91 years) were recruited from adolescent inpatient alco
hol and drug treatment centers and assessed at six and 12 months after disc
harge. Of the youths studied, 79% had used one or more substances by 12-mon
th follow-up. Although only 1% reported alcohol as their substance of choic
e while hospitalized, alcohol was involved in 46% of initial posttreatment
use episodes. Almost a quarter (23%) of initial posttreatment substance use
events involved multiple substances. Initial posttreatment use episodes in
volving multiple substances and preferred substances were associated with p
oorer outcomes during the year following treatment both in terms of rate of
return to and severity of substance involvement. Youths who initially used
only alcohol were also likely to resume harmful levels of substance involv
ement by one year after treatment. Results suggest two routes, gateway and
preferred substance, for adolescents in the resumption of harmful substance
use following treatment. This gateway role merits consideration by adolesc
ent substance abuse treatment providers and families of treated youths.