November 13, 2006 (Toronto) — Teenagers experience cannabis withdrawal symptoms such as nervousness and anxiety that are clinically significant, according to prospective research presented here at the annual meeting of the Canadian Psychiatric Association.
"It was a difficult drug for them to stop using," said Robert Milin, MD, FRCPC, the study's principal investigator and an assistant professor in the Department of Psychiatry at the University of Ottawa and director of the youth psychiatry program at the Royal Ottawa Hospital/Institute of Mental Health Research in Ottawa, Ontario, Canada. "We found that they had clear withdrawal symptoms, and they had a level of distress associated with those symptoms.
"There were physiological symptoms such as drug craving and physical symptoms such as restlessness and anxiety," said Dr. Milin. "They had these symptoms despite using cannabis for less than 3 years. There is some thought that you can stop cannabis whenever you like without having any discomfort. This is evidence that adolescents have cannabis dependence with physiological symptoms, and this may add to the volume of literature that adolescents may be in a particular period of greater vulnerability to cannabis dependence than adults."
Dr. Milin noted that most literature and opinion supports that adults experience withdrawal symptoms when quitting cannabis, but that the existing literature and opinion do not support that teens experience withdrawal symptoms.
The study enrolled 21 subjects aged 13 to 19 years who had either entered a residential treatment program (n = 13) or outpatient treatment program (n = 8) for substance abuse. Investigators excluded youths who were undergoing nicotine cessation or had a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), diagnosis of dependence on substances other than cannabis. A total of 14 men and 7 women participated. The mean age of patients was 17 years, and their mean educational level was ninth grade.
Investigators conducted weekly assessments until a minimum of 14 days of abstinence was achieved.
Youths used an average of 3.85 g of cannabis daily for a total of 6 of every 7 days for 2.9 years prior to entering a withdrawal program. The average age of onset of cannabis use was 14.2 years. All youths used nicotine daily. Male paticipants began using cannabis at an earlier age than females: 12.1 vs 13.6 years.
A total of 13 of 21 participants completed the study, with the majority of those who completed the study in residential treatment programs (n = 10) and the remaining participants in outpatient programs, a finding that was statistically significant. Urinalyses were conducted for 10 completers, all of which were negative.
"The youths who were in residential programs saw themselves as having greater dependence on cannabis, which is why they entered these programs," said Dr. Milin.
A total of 11 youths reported relapsing to alleviate withdrawal symptoms while 6 reported relapsing for other reasons.
In terms of measuring the association of withdrawal symptoms and the overall severity of withdrawal syndrome using a visual analog scale, symptoms at week 3 such as irritability, depression, twitches and shakes, perspiring, thoughts of cannabis, and craving for cannabis were all statistically significant (P < .05 for each).
The findings contribute to the evidence for classifying cannabis withdrawal as a diagnosis under the DSM-IV, according to David Crockford, MD, FRCPC, head of the addiction section of the Canadian Psychiatric Association and an assistant professor in the Department of Psychiatry at the University of Calgary in Alberta, Canada.
"This fits with other studies in that they found people who are heavy users experience cannabis withdrawal, experiencing symptoms such as anxiety and insomnia," said Dr. Crockford. "This is further support for the classification of cannabis withdrawal as a diagnosis in the substance use disorders in the DSM."
Dr. Crockford noted recruitment for such a study is a challenge because youths may be using other substances apart from cannabis. "It's an exceedingly difficult study to do because adolescents often just don't use one substance," he said. "They use lots."
The University of Ottawa Medical Research Fund supported the study. Dr. Milin is an investigator for AstraZeneca. Dr. Crockford reported no relevant financial relationships.
CPA 2006 Annual Meeting: Abstract S12b. Presented November 10, 2006.
Medscape Medical News © 2006
Cite this: Louise Gagnon. Teens Experience Cannabis Withdrawal Symptoms - Medscape - Nov 13, 2006.