Transcranial Magnetic Stimulation for Methamphetamine Use Disorder During Pregnancy

This is a three-arm, randomized, controlled feasibility trial evaluating transcranial magnetic stimulation (TMS) as a potential treatment for methamphetamine use disorder (MaUD) during pregnancy. The study aims to 1) assess the feasibility of recruitment, retention, and intervention delivery among pregnant women with MaUD, 2) assess the feasibility of collecting maternal health outcomes, and 3) assess the feasibility of collecting postnatal neonatal outcomes.

Up to 45 pregnant participants will be enrolled and randomized in equal proportions (1:1:1) to: (1) standard TMS (16 sessions over 4 weeks), (2) accelerated TMS (aTMS; 16 sessions over 2 weeks), or (3) treatment as usual (TAU). The TAU group will continue with existing care, including contingency management, behavioral counseling, and other standard treatments available in the community. Randomization will be stratified based on the presence of co-occurring substance use disorders and implemented using a secure REDCap randomization module with permuted block allocation. Participants will be followed through pregnancy and until 6 months postpartum.

Eligible participants are pregnant women aged 22 years and older with a diagnosis of active methamphetamine use disorder and a gestational age of 34 weeks or less at enrollment. Participants with contraindications to TMS or medical or psychiatric conditions that substantially increase risk, including seizure disorders, bipolar I disorder, schizophrenia spectrum disorders, or active alcohol use disorder, will be excluded.

All TMS procedures will be conducted at the Huntsman Mental Health Institute using a TMS system with theta burst stimulation capabilities. Treatment will utilize a dual-target stimulation approach consisting of excitatory intermittent theta burst stimulation (iTBS) directed at the dorsolateral prefrontal cortex (DLPFC) and inhibitory continuous theta burst stimulation (cTBS) directed at the medial prefrontal cortex (mPFC). Stimulation intensity will be individualized using each participant's resting motor threshold and gradually increased during initial treatment sessions as tolerated.

Participants randomized to the standard TMS arm will receive 16 treatment sessions delivered over 4 weeks. Participants randomized to the accelerated TMS arm will receive the same total number of treatment sessions delivered over 2 weeks using an accelerated treatment schedule. Participants assigned to treatment as usual will continue receiving available evidence-based clinical care without TMS.

The primary feasibility outcomes include recruitment rates, screening completion, enrollment rates, randomization success, retention throughout treatment and follow-up, completion of TMS sessions, participant adherence, and completion of study assessments. Acceptability outcomes include participant satisfaction, treatment burden, and willingness to participate in future TMS studies.

Maternal outcomes will be collected throughout pregnancy and during follow-up and will include measures of methamphetamine use frequency, substance use severity, craving, depression, anxiety, sleep quality, quality of life, cognitive functioning, urine drug testing results, and physical health indicators. Data will be collected using validated self-report instruments, clinical assessments, medical record review, and biologic measures where applicable.

Neonatal outcomes will be assessed through medical record review and follow-up assessments and will include gestational age at delivery, birth weight, Apgar scores, neonatal intensive care unit admission, neonatal length of stay, and developmental outcomes through 6 months postpartum. Infant development will be evaluated using the Ages and Stages Questionnaire, Third Edition (ASQ-3), and supplemented by pediatric health record review when available.

This study is not powered to evaluate treatment efficacy. Rather, the purpose of the study is to establish the feasibility and acceptability of TMS for methamphetamine use disorder during pregnancy and to determine the feasibility of collecting maternal and neonatal outcome data needed for a future fully powered randomized clinical trial.