Transcranial Magnetic Stimulation May Curb Withdrawal Symptoms in Meth Addicts

By Marilynn Larkin 

NEW YORK—Repetitive transcranial magnetic stimulation (rTMS) targeting the left dorsa-lateral prefrontal cortex (DLPFC) can reduce withdrawal symptoms in men with amphetamine addiction, facilitating detoxification, researchers in China say.

"TMS has been used to treat cravings for heroin, methamphetamine and cocaine, and to decrease the use of nicotine and alcohol," Dr. Ti-Fei Yuan of Shanghai Jiaotong University School of Medicine told Reuters Health by email. "However, this is the first application for acute withdrawal symptoms and associated sleep and mood changes."

Dr. Yuan and colleagues randomly assigned 48 men with methamphetamine addiction (mean age, 33.3) to high (10 Hz for 10 minutes) rTMS targeting the DLPFC or sham rTMS. Participants were treated for five days followed by two days of rest, then treated for another five days.

There were no significant differences between the groups with respect to age, educational level, race, mean body mass index, mean length of abstinence (about a week), mean duration of methamphetamine use (about five years) or dosage (about 0.5 grams/day).

As reported online September 12 in JAMA Psychiatry, various statistical analyses of scores on a Chinese version of the methamphetamine withdrawal symptom scale, the Pittsburgh Sleep Quality index and self-rating scales for depression, anxiety and cue-induced craving "demonstrated significant changes" in the intervention group but not in the sham group.

Further, a reduced craving score correlated positively with reductions in withdrawal symptoms, improvements in sleep and decreased severity of anxiety, but not depression scores.

Certain patients are likely to be more responsive than others, Dr. Yuan noted. "Many factors affect TMS-induced behavior changes," including genetic variations affecting plasticity responses (e.g., BDNF genotype); variation in skull/brain shape; sex hormones, which affect TMS responsiveness; and brain connectivity state.

Additional research is needed, he added, to determine whether TMS has a long-lasting effect or can help prevent relapse; the appropriate target, frequency and intensity of treatment for different individuals; whether pharmacological agents can enhance the TMS treatment effect; and effect of TMS on social, risky "and even criminal behaviors of addicts."

China has a large population of about 2.5 million addicts on record and an estimated 10-13 million methamphetamine/heroin abusers, Dr. Yuan said. "We sincerely wish to (collaborate) with international scientists and clinicians to (further) our research."

Dr. Kevin Reeves, Chief, Section of Interventional Psychiatry at Ohio State University Wexner Medical Center in Columbus, said he agrees with the findings. "This indication is still experimental," he told Reuters Health. "However, there are at least 26 studies registered with clinicaltrials.gov, so the evidence is building."

"We have treated patients (with TMS) primarily for depressive disorders," he said by email, "although a minority did have comorbid substance use disorders in various stages of remission."

Like Dr. Yuan, Dr. Reeves noted, "There remains a need to clarify the optimum stimulation parameters, including duration of treatment, strength of stimulation and target population."

"TMS can result in an elevated risk of seizure in patients who are in acute withdrawal from some substances (sedatives, hypnotics and anxiolytics and possibly opioids), which would need to be further investigated to determine the safety profile," he added.

"Larger studies across different sites would be the next step towards establishing a clinical treatment indication," he concluded. "It would be interesting to include neurophysiologic studies including brain imaging or evoked potentials to demonstrate a change in the brain's response beyond symptom rating scales."

SOURCE: https://bit.ly/2OE0MkA

JAMA Psychiatry 2018.

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