LOS ANGELES – Persistent cravings, as opposed to a difficult struggle with withdrawal, are likely responsible for the grip of methamphetamine on addicted individuals who want to quit, according to results of an inpatient study presented at the annual meeting of the American Association of Addiction Psychiatrists.
Researchers at the University of California, Los Angeles, admitted 66 non–treatment-seeking methamphetamine-addicted patients and 89 healthy controls to an inpatient clinical research center for up to 5 weeks as part of several imaging studies conducted as those patients addicted to methamphetamine withdrew from the drug.
The addicted patients were active users at admission and were monitored daily via urine screening to ensure that they remained abstinent throughout their hospitalizations.
To study the “pure” effects of methamphetamine withdrawal, those addicted were excluded if they were simultaneously addicted to other substances (except nicotine) or if they had pre-existing psychiatric diagnoses or serious medical conditions, said Dr. Todd Zorick of the Center for Addictive Behaviors at UCLA.
Methamphetamine-dependent subjects were compared with matched healthy control subjects on the Beck Depression Inventory (mood), and Brief Symptom Inventory (general psychiatric symptoms, including hostility, anxiety, depression, and psychosis).
Addicted subjects experienced a variety of prominent withdrawal symptoms on days 1–3, including diarrhea, red/itchy eyes, suicidal thoughts, and mild psychotic symptoms.
Symptoms of psychoticism, obsessional behavior, interpersonal sensitivity, hostility, and paranoia, and somatic symptoms were “quite high” early on, particularly in the first 24–48 hours of abstinence.
On days 4–14, other symptoms came to the fore, including a lack of motivation, increased appetite, sleep difficulties, and fatigue, Dr. Zorick reported.
However, most of these symptoms were mild, manageable, and gradually declined over time.
“Pretty much anything we saw [in these symptom clusters] was gone in 2 weeks,” he said.
Depression symptoms, which have been hypothesized to drive relapse, were elevated over those of healthy controls at study entry but generally declined over 4 weeks. Although a small subset of patients had Beck Depression Inventory scores that persisted at a mean level of about 12 on the 0–63 scale, most had scores at 1 month that were “at least as low or lower” than scores of healthy controls.
What did persist was craving, which began at a mean of 40–50 on a 0–100 visual analog scale and remained in the 20–30 range at the end of week 1.
Over the first 14 days of abstinence, cravings subsided somewhat, but for many users, the desire for methamphetamine did not completely wane even after a month had passed since last use.
“Even at week 5, [craving is] not zero,” Dr. Zorick said. “These are people who haven't touched meth in 5 weeks. [They] are still thinking about meth a lot [in a controlled, hospital environment]… not being exposed to it whatsoever.”
Craving scores were not associated with depression symptoms except during weeks 1 and 2 of abstinence, he noted.
Dr. Zorick said the results might serve to inform clinicians about the clinical course of withdrawal in their patients and the need to continue to address craving over the long term.
“If you get somebody in your office who recently quit methamphetamine or is trying to quit… he's likely to experience a lot of psychiatric symptoms, including hostility, paranoia, interpersonal sensitivity, and high levels of depression,” he said. “These are not happy people.
“However, the good news is that these symptoms decrease to a pretty low baseline on average within the first 2 weeks or so.”
At that time, “they are likely to feel a lot better, not experiencing depression, no psychotic symptoms, sleep normalized, but they may have high levels of craving for methamphetamine.”
No drugs have been approved by the Food and Drug Administration to reduce craving in patients addicted to methamphetamine who are attempting to quit, although this should be a crucial goal for future research, Dr. Zorick said.
Dr. Zorick's research and that of Edythe London, Ph.D., also of UCLA and the principal investigator of the inpatient imaging studies, were sponsored by government grants.
Neither investigator reported any relevant financial disclosures.