Repetitive Transcranial Magnetic Stimulation in Drugs Addiction

The Application of Repetitive Transcranial Magnetic Stimulation (rTMS) as an Adjunct Therapy in Reduction of Craving and Consumption of Illicit Drugs

This study also aims to develop and apply a standard repetitive transcranial magnetic stimulation (rTMS) protocol on drug users. The investigators want to focus on the effects of rTMS on amphetamine and cocaine as they are the most commonly used types of illicit drugs in Hong Kong.

The primary research question is:

• To examine if rTMS can reduce craving and consumption of the most commonly used illicit drugs (amphetamine, cocaine) among people with drug use disorders in Hong Kong?

The secondary research questions are:

• What is the association between rTMS protocol (frequency, intensity) and drug craving and consumption?
• Would there be gains in executing functioning among participants who have received rTMS treatment?
• Would there be a reduction in depressive and anxiety symptoms among participants who have received rTMS treatment?

The investigators would use a cross-over design (figure 1) to investigate the effects of rTMS. The investigators would recruit participants through community drug rehabilitation and youth outreach services. Participants who meet the selection and exclusion criteria will be invited to join. Upon obtaining their written consent, the investigators would randomize participants to a treatment (rTMS) group and a sham stimulation (placebo) group. Upon completing the first phase (2 weeks), there would be a washout period of 2 weeks. The two groups will swap (treatment becomes sham, and vice-versa) and the second phase will proceed. A double-blinded procedure will be implemented. Outcome measures will be conducted at baseline, after Phase I, at the start of Phase II, and at the end of Phase II.

Inclusion Criteria:

1. Aged 18 to 60.
2. Illicit drug users in the community (not in institutions).
3. Uses either amphetamine (ice) and/or cocaine frequently (at least 4 times per week).
4. Craving Visual Analogue Scale (VAS, 11-point from 0 - 10) score of at least 5 or above on either amphetamine or cocaine.
5. Interest in participating in drug treatment or rehabilitation or have already engaged in such services offered by health or social services.
6. Not engaged in pharmacological or physical treatment related to substance use disorders in past six months.

Exclusion Criteria:

1. Have a history of seizures or a family history of epilepsy.
2. Have severe mental disorders like bipolar disorder or psychosis.
3. Have brain damage from illness or injury, such as a brain tumor, a stroke or a traumatic brain injury.
4. Have any metal or implanted medical devices in the body.
5. Have frequent or severe headaches.
6. Pregnant or thinking of becoming pregnant.
7. Had prior treatment with rTMS in the past year.