Among teens with substance use disorders, those who also have social anxiety disorder begin using marijuana at a mean age of 10.6 years — an average of 2.2 years earlier than teens without anxiety, according to a study conducted at Case Western Reserve University School of Medicine.
“This finding surprised us,” said principal investigator Alexandra Wang, a third-year medical student at the university. “It shows we need to start earlier with prevention of drug and alcohol use and treatment of social phobia [in children].”
The study involved 195 teens (102 girls, 52 percent), aged 14 to 18 years, who met the current diagnosis of substance use disorder and had received medical detoxification if needed.
Researchers assessed the teens’ history of drug and alcohol use and looked into whether they’d had any of three anxiety disorders: social anxiety disorder, panic disorder, and agoraphobia.
Marijuana was the most popular drug of choice. Of the 195 participants, 92 percent had marijuana dependence, starting at a mean age of 13 years; 61 percent were alcohol-dependent, having started drinking at 13.5 years on average.
Teens with either social anxiety disorder or panic disorder were far more likely to have marijuana dependence, Wang said. Both of these disorders were more likely to occur before marijuana dependence.
Approximately 80 percent of teens with social anxiety disorder and 85 percent with panic disorder had symptoms of that disorder before the onset of their substance abuse. Furthermore, panic disorder tended to start before alcohol dependence and occurred in 75 percent of alcohol-dependent adolescents.
There was no clear evidence showing whether agoraphobia came before or after either marijuana use or the first drink, according to the authors.
A limitation of the study, according to the research team, was that 128 (66 percent) of the teens were juvenile offenders who had received court-referred treatment for their substance abuse. These findings might not generalize to a less severely addicted population.
Still, interventions to reduce social anxiety might help prevent substance abuse in teens.
“We need to treat these young patients initially with nonpharmacologic means, such as cognitive behavioral therapy or mindfulness meditation,” said Christina Delos Reyes, M.D., a psychiatrist specializing in addictions at University Hospitals Case Medical Center.
Patrick Bordeaux, M.D., a child and adolescent psychiatrist in Quebec, Canada, said that “comorbidities tend to be the rule in adolescents, not the exception.”
“Adolescents are more likely to have social and mental disorders that make them more likely to use drugs,” said Bordeaux, who was not involved with the study.