This study will develop and evaluate the preliminary efficacy and cost-effectiveness of a mobile phone-delivered psychosocial intervention for opioid-dependent adults (N=219) in methadone maintenance treatment (MMT). A three-arm, randomized clinical trial will evaluate the relative efficacy of: (1) standard MMT; (2) standard MMT plus the mobile intervention; and (3) a mobile-based control condition on the primary outcomes of treatment retention and opioid use (assessed via urine toxicology). If results are promising, this novel therapeutic tool may have a tremendous impact on improving access to and effectiveness of substance abuse treatment in a variety of other populations (and could also be adapted for an array of other behavioral health applications), while significantly limiting costs.

This study will develop and implement a mobile technology-delivered psychosocial intervention for opioid-dependent adults in methadone maintenance treatment (MMT). This novel therapeutic system promises to be cost-effective and to enable the provision of flexible, on-demand therapeutic support outside of the formal treatment setting. The specific aims of this investigation are as follows: Aim 1: The investigators will develop a novel, interactive, evidence-based psychosocial intervention delivered via mobile phones, designed to promote skills acquisition and reduce illicit drug use. Specifically, our Mobile Therapeutic System (MTS) will offer key elements of a psychosocial intervention for substance use disorders of known efficacy (the Community Reinforcement Approach). Participants will be provided with unlimited daily prompts to encourage use of the program and will be able to access the application at any time and as much as they choose, within their natural environments. Our iterative development process will include input from focus groups with clients in methadone treatment (n=24), input from experts in the field, and feedback testing of a beta-version of the mobile phone-based program with clients in methadone treatment (n=30). Aim 2: The investigators will evaluate the efficacy of this mobile tool with participants entering MMT during the first three months of their treatment (n=219). The investigators will evaluate the relative preliminary efficacy of (1) standard treatment, (2) standard treatment plus MTS and (3) a mobile-based control condition on the primary outcomes of retention and opioid use (via urine toxicology) and secondary outcomes of other substance use (via urine toxicology and self-report), readiness to change drug use behavior, coping skills, opioid craving, HIV risk behavior, and psychosocial functioning during the 3-month intervention phase. Durability of effects will be examined at 1 and 3 month follow-ups. Aim 3: The investigators will perform an economic analysis of MTS in community-based MMT. The investigators will estimate the incremental costs and the incremental cost-effectiveness ratio (ICER) of MTS relative to standard care and the mobile control group. The primary ICER will be the incremental costs per increased abstinence time (the clinical measure of effectiveness) and the secondary ICER will be incremental costs per increased quality adjusted life year (QALY) (the economic measure of effectiveness). Cost data will be vital to future translational projects to disseminate effective mobile interventions in community systems. If results are promising, this novel therapeutic tool may have a tremendous impact on improving access to and effectiveness of substance abuse treatment in a variety of other populations (and could also be adapted for an array of other behavioral health applications), while significantly limiting costs.

Inclusion Criteria:

• client enrolled in the study site's methadone maintenance program
• within the first month of initiating methadone maintenance treatment
• 18 years of age or older
• sufficient English-language ability to participate in informed consent process, complete study assessments and understand the text in mobile phone- delivered interventions

Exclusion Criteria:

• entering treatment at the study site with the intention of receiving a methadone-assisted withdrawal only
• evidence of an active psychiatric disorder requiring immediate intervention (e.g., suicidality, psychosis)
• evidence of significant mental illness that may preclude participation