Repetitive dTMS Intervention for Methamphetamine Addiction
Condition: Methamphetamine-dependence
MeSH terms: Behavior, Addictive
Study type: Interventional

Summary: 
      A growing body of evidence suggests a wide range of brain areas including medial prefrontal
      cortex (mPFC), dorsolateral prefrontal cortex (DLPFC) and other subcortical regions, such as
      anterior cingulate cortex (ACC) are critical for regulating cognitive control over decisions
      and involving in drug related cue processing. Previous studies have demonstrated that
      transcranial magnetic stimulation (rTMS) over dorsolateral prefrontal cortex reduces craving
      for meth dependences. Specifically, the H7 coil induces a magnetic field can target mPFC and
      ACC. In this study, the investigators investigated whether repeated dTMS intervention of
      medial prefrontal and cingulate cortices in methamphetamine addiction could reduce the
      subjective craving and improve the cognitive abilities.
    

Detailed description: 
      The study will be conducted at the drug rehabilitation center in China. The whole procedure
      includes enrollment, pre-intervention evaluation, intervention (for 3 weeks, 5 times a week,
      15 times in total), post-intervention evaluation and one month follow up evaluation.

      In enrollment session, participants are recruited according to inclusion criteria.

      In the pre-intervention evaluation, firstly, participants need complete a questionnaire to
      assess their demographic information, drug addiction history and drug abstinence. And then
      are assigned to either 10Hz group or sham group according to the counterbalance of their
      basic demographic and drug use information. Then, participants need complete craving,
      cognitive ability and electroencephalogram (EEG) assessment. For craving assessing,
      participants are shown a video of methamphetamine usage for 5 minutes, and then rated on the
      visual analogue scale (0 means completely undesired and 100 means extremely wanting) to
      report their craving for methamphetamine. For cognitive ability and EEG signal assessing, the
      whole process is conducted on the computer according to instructions.

      In the intervention session, dTMS was administered using a TMS stimulator (Magstim, U.K.)
      equipped with a unique H-shaped coil design. The H-coil version used in this study was the H7
      (Brainsway, Jerusalem, Israel). When placed 4-5 cm anterior to the foot motor cortex and used
      at 100% of the leg resting motor threshold (RMT), the H7 coil stimulates the dorsal mPFC and
      ACC bilaterally. A participant's RMT was determined before the first treatment and at the
      beginning of each week by ascertaining the coil position that elicited the minimal
      involuntary contractions of the feet (three of six attempts). The 10Hz group received 10 Hz
      dTMS at 100% of RMT, with 3-second pulse and 17-second intervals, for a total of 50 trains
      and 1500 pulses per session. The sham group received treatment with identical technical
      parameters, which induced scalp sensations but without penetration of the electric field into
      the brain.

      Post-intervention evaluation and one month follow up evaluation are the same as in
      pre-intervention evaluation.

      To ensure study quality, some measures are taken as bellow:

      Researchers and drug rehabilitation staff will work together in whole process and the data
      will be converted into electronic versions once finishing each evaluation.

      In the intervention, patients, operators, and raters were blind to treatment condition. Each
      patient is assigned a magnetic card that determined the coil (real or sham) in the helmet and
      raters are not present while treatments are administered.

      After each treatment times, any side effect from participant's report are recorded to assure
      the safety and feasibility.

      Statistical analyses are performed using SPSS 21.0. The principal statistical analysis is
      performed using repeated-measures analysis of variance and regression analysis. All missing
      data will be recorded and marked.
    

Intervention name(s): real coil; sham coil
Intervention type(s): Device; Device
Intervention description(s): active 10Hz with a train of 3s on / 17s off, 50 trains, a total of 1500 pulses; sham 10Hz with a train of 3s on / 17s off, 50 trains, a total of 1500 pulses
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: deep transcranial magnetic stimulation; methamphetamine addiction