Methamphetamine Cravings Persist, Remain Intense, Well Into Abstinence
December 14, 2009 (Los Angeles, California) — Long after most of the psychological and physical symptoms of methamphetamine withdrawal have resolved, a significant proportion of previously addicted individuals who have achieved abstinence continue to experience intense cravings for the drug, according to a study presented here at the American Academy of Addiction Psychiatry 20th Annual Meeting & Symposium. This finding, researchers say, likely represents a major challenge to permanently breaking the cycle of addiction.
A study conducted by investigators at the University of California, Los Angeles, showed that although average levels of craving and psychopathology decreased for all methamphetamine-dependent subjects after 2 weeks of abstinence, up to 30% of these individuals continued to experience significant levels of craving, depressive symptoms, and/or psychotic symptoms after 5 weeks.
"We thought it was interesting that subjects were still having relatively high levels of cravings, even after having been clean for 5 weeks in a hospital ward and completely isolated from the environment where they used methamphetamine,” lead author Todd Zorick, MD, PhD, told Medscape Psychiatry.
According to the investigators, methamphetamine use is increasing worldwide and has reached epidemic levels in the western United States, including California.
Currently, there are no medications approved by the US Food and Drug Administration (FDA) to treat stimulant dependence, and current psychosocial treatment modalities have limited effectiveness, the investigators note.
To better understand factors that may lead to relapse and gain insight into the physical, emotional, psychiatric, and psychophysiological time course of symptoms experienced by these individuals during abstinence, the investigators recruited 56 methamphetamine-dependent volunteers.
All subjects met criteria for methamphetamine dependence, were not dependent on other substances, aside from nicotine, and were confirmed via urine testing to be active users. All subjects were also prescreened for the absence of comorbid medical or psychiatric disease to evaluate “pure” methamphetamine addicts.
Study participants were housed in an inpatient clinical research center for 5 weeks and underwent daily urine testing to confirm abstinence and were monitored for withdrawal symptoms.
Methamphetamine-dependent subjects had high levels of depressive, mood, and psychotic symptoms before abstaining from the drug but had significant decreases in their levels of psychopathology by the end of the first week of abstinence.
Subjects’ withdrawal symptoms generally resolved within 2 to 6 days, were fairly mild, and included red/itchy eyes, poor memory, lack of energy, lack of motivation, anger, and irritability.
Although many participants experienced a significant decrease in cravings after 2 weeks, up to one-third continued to experience cravings or depressive and/or psychotic symptoms for up to 5 weeks.
Dr. Zorick emphasized that the fact that the subjects had no psychiatric comorbidities unrelated to methamphetamine use represented an important study limitation. However, he said that the evaluation of "pure" methamphetamine addicts provides a clearer understanding of the effects methamphetamine-dependent users experience in abstinence. The researchers are continuing to analyze the data. He told Medscape Psychiatry that final figures are not yet available.
Treatment for such patients is particularly challenging without any existing FDA-approved drug to address cravings, and cognitive behavioral therapy takes time.
"Cognitive behavioral therapy is uneven in its applicability for these patients," Dr. Zorick said. "It can work to some extent, but it requires a lot of time and multiple sessions and may not be available for everyone."
Findings Not Surprising
According to Peter Martin, MD, professor of psychiatry and pharmacology at Vanderbilt University Medical Center in Nashville, Tennessee, methamphetamine-dependent patients often have additional psychiatric comorbidities, and addressing those can sometimes help addiction treatment.
“A lot of these cravings can be helped first by determining whether there are other psychiatric diagnoses and appropriately treating those,” he told Medscape Psychiatry.
"If there are no diagnoses and it’s just purely methamphetamine addiction, then there are opportunities to treat the impulsivity that go along with the use of the methamphetamine, with some people using mood stabilizers, for instance."
Dr. Martin, who authored Healing Addiction: An Integrated Pharmacopsychosocial Approach to Treatment, describes a multifactorial approach.
“All addictive disorders are biopsychosocial illnesses, with biological, psychological, and social components, and with a careful assessment of methamphetamine-dependent patients, one can put together a strategy with pharmacologic, psychological, and social components,” he said.
Dr. Martin noted that the study’s findings of cravings extending 5 weeks into methamphetamine abstinence were not surprising.
"It is nice to have this demonstrated in a meticulous clinical study, but it is not surprising to me at all. The most important thing to understand — going beyond methamphetamine — is we need to think of addictions as lifelong disorders," he said.
“The currency of addiction is learning and memory, and once you’ve had an experience, that experience has its traces in the neural pathways of the brain, so the addict has learned this experience, and of course if it was highly pleasurable and rewarding, it’s not surprising that memories leave these traces in the brain.”
The study was funded by the National Institutes of Health. Dr. Zorick and Dr. Martin have disclosed no relevant financial relationships.
American Academy of Addiction Psychiatry (AAAP) 20th Annual Meeting & Symposium. Presented December 6, 2009.