APA: Cannabis Withdrawal Syndrome No Pot Dream
By Michael Smith,
MedPage Today Staff Writer
May 26, 2006
TORONTO, May 26 —
The so-called "cannabis withdrawal syndrome" is
real and should be added to diagnostic manuals.
So asserted Deborah
Hasin, Ph.D., of Columbia's Mailman School of
Public Health at the American Psychiatric
Association meeting here.
Dr. Hasin based her
conclusion on data gleaned from the landmark
National Epidemiologic Survey on Alcohol and
Related Conditions (NESARC), a national
longitudinal study of more than 43,000 Americans
with respect to their alcohol and drug use,
conducted in 2001 and 2002.
withdrawal at this point really should be added to
the DSM-V and the ICD-11," she said. The
Diagnostic and Statistical Manual of Mental
Disorders, now in its fourth edition, is being
revised. The International Classification of
Diseases (ICD) is established by the World Health
Among the questions
asked in structured interviews were a number about
after-effects of drug use, and Dr. Hasin and
colleagues examined the answers from 2,6113
participants who identified themselves as having
used marijuana three or more times a week during
their period of heaviest drug use.
The most common
side-effects after stopping marijuana use were
feeling weak or tired, yawning, hypersomnia,
psychomotor retardation, and anxiety and
depression, Dr. Hasin said.
Many of those
participants also used other drugs, Dr. Hasin
said, so to avoid confounding, the researchers
restricted their analysis to 1,119 people who used
marijuana heavily—more than three times a week—but
didn't indulge in binge drinking or use other
included some very heavy users—two-thirds smoked
the drug between five and seven days a week, and a
similar proportion smoked at least one joint a
day, she said.
The same set of
symptoms appeared, Dr. Hasin said, indicating that
other drugs were not causing them.
analysis, the researchers classed the major
symptoms into two clusters—slowness, which
included sleeping more, feeling weak or tired, and
yawning, and depression/anxiety, which included
sweating/heart beating, anxiety, restlessness,
insomnia, depression, muscle aches, and shaking.
Two key questions,
she said are whether the symptoms cause distress
or impairment and whether the participants turned
to other drugs or returned to marijuana to avoid
the distress. A negative binomial regression
analysis showed that:
- Both symptom
clusters were associated with distress or
impairment. The association was significant at
- And both were
associated with using drugs to avoid the
distress, again at P<0.01.
clusters were associated with heavy use, at P<0.05,
but not with the age at which participants started
using the drug, Dr. Hasin said. The duration of
the period of heaviest use was associated with the
anxiety cluster but not with slowness, the
Dr. Hasin said the
epidemiological approach allowed the researchers
to overcome problems that had dogged earlier
studies of the issue, including such things as
small numbers, unrepresentative samples, and
confounding by other drug use.
But that may not be
enough to claim that the symptoms seen are true
withdrawal, said Nicholas Seivewright, M.D., a
consultant psychiatrist with the Community Health
Sheffield NHS Trust in Great Britain and author of
Community Treatment of Drug Misuse.
Citing the case of
benzodiazepines, Dr. Seivewright noted that the
central argument for a withdrawal syndrome with
those drugs was the emergence of novel symptoms
that patients had not previously had but incurred
after stopping. In the case of marijuana, he said,
"I'm a bit concerned about how you can call these
withdrawal symptoms" without knowing that they
aren't a rebound effect or part of a pre-existing
Dr. Hasin may be
"jumping the gun" in labeling her symptom clusters
cannabis withdrawal, he said in an interview.