Shoptaw, S., Rawson, R. A., McCann, M. J., & Obert, J. L. (1994). The Matrix Model of outpatient stimulant abuse treatment: Evidence of efficacy. Journal of Addictive Diseases, 13(4). 129–141. https://doi.org/10.1300/J069v13n04_02

Type of Study: Randomized controlled trial
Number of Participants: 146

Population:

• Age — Typical age=31 years
• Race/Ethnicity — 62% Caucasian, 27% African American, and 12% Latino
• Gender — 19% Female, 81% Male
• Status — Participants all met DSM-III-R diagnoses for stimulant abuse or dependence.

Location/Institution: Matrix Institute on Addictions, UCLA Department of Psychiatry, CA

Summary: (To include basic study design, measures, results, and notable limitations)
The purpose of the study was to examine the effectiveness of Matrix Model for Adults [now called Matrix Model Intensive Outpatient Program] outpatient stimulant treatment by associating subjects' in-treatment abstinence data, treatment lengths, and weekly treatment activities to their 6-month abstinence outcomes. Participants were randomly assigned to one of three treatment conditions: Matrix Model for Adults treatment only, Matrix Model for Adults treatment plus desipramine (an antidepressant that may reduce cocaine withdrawal symptoms), or Matrix Model for Adults treatment plus placebo. Measures utilized include the Addiction Severity Index (ASI), Behavioral Change Index (BCI), Center for Epidemiological Studies-Depression (CES-D), as well as urinalyses and self-report measures during treatment, at 6-months, and 12-months after treatment entry. Results indicated that those who received longer Matrix Model for Adults treatment episodes demonstrated better abstinence outcomes. Ethnicity was one subject characteristic that associated significantly with outcome; African American subjects, for example, had significantly fewer weeks in treatment than Caucasian subjects. Methamphetamine-dependent participants showed significantly better abstinence outcomes than cocaine participants in attaining abstinence for 3 consecutive weeks, for 8 consecutive weeks, and at 6-month follow-up. Through 6 months of treatment, participants averaged 67.3% negative results on the drug tests. Limitations include the lack of a no-treatment control group and the variation in lengths of treatment among participants.

Length of controlled postintervention follow-up: Varied; 6-month follow-up, but some had 6 months of treatment.

Rawson, R. A., Shoptow, S. J., Obert, J. L., McCann, M. J., Hasson, A. L., Marinelli-Casey, P. J., Ling, W. (1995). An intensive outpatient approach for cocaine abuse treatment: The Matrix Model. Journal of Substance Abuse Treatment, 12(2), 117–127. https://doi.org/10.1016/0740-5472(94)00080-B

Type of Study: Randomized controlled trial
Number of Participants: 100

Population:

• Age — Mean=31 years
• Race/Ethnicity — 50% Caucasian, 27% African American, 23% Latin American
• Gender — Not specified
• Status — Participants were all cocaine abusers seeking treatment.

Location/Institution: Matrix Institute in California

Summary: (To include basic study design, measures, results, and notable limitations)
The purpose of the study was to determine the efficacy of the Matrix Model for Adults [now called Matrix Model Intensive Outpatient Program]. Participants were randomly assigned to a Matrix Model for Adults treatment condition or to a condition of referral to treatment at "other available community resources." Measures utilized include urinalyses, time-line follow-back self-report technique, the Addiction Severity Index (ASI), the Profile of Mood States (POMS) and the Center for Epidemiologic Studies-Depression (CES-D). Results indicate that both groups of subjects reported significant reductions in their cocaine use over the 12-month study period. Limitations include the variation in treatment length among subjects, and reliance on self-reported measures.

Length of controlled postintervention follow-up: 6–11 months (treatment ranged from 4 weeks to 6 months, with 12-month post-intake follow-up).

Rawson, R. A., Marinelli-Casey, P., Anglin, M. D., Dickow, A., Frazier, Y., Gallagher, C., Galloway, G. P., Herrell, J., Huber, A., McCann, M. J., Obert, J., Pennell, S., Reiber C., Vandersloot, D., Zweben, J., & The Methamphetamine Treatment Project Co A multi-site comparison of psychosocial approaches for the treatment of methamphetamine dependence. Addiction, 99(6), 708–717. https://doi.org/10.1111/j.1360-0443.2004.00707.x

Type of Study: Randomized controlled trial
Number of Participants: 978

Population:

• Age — 18+ years
• Race/Ethnicity — 60% Caucasian, 18% Hispanic, and 17% Asian/Pacific Islander
• Gender — 45% Male, 55% Female
• Status — Participants were all methamphetamine (MA)-dependent & were recruited through a variety of means, including media advertisements, referrals from community agencies, and word of mouth.

Location/Institution: Eight community out-patient settings: Women's Addiction Treatment Center of Hawaii, Honolulu, HI; San Mateo County Alcohol and Drug Services, Belmont, CA; New Leaf Treatment Center, Concord, CA; Matrix Institute on Addictions, Costa Mesa, CA; Matrix Institute on Addictions, Los Angeles, CA; The Family Recover Center, Eye Counseling and Crisis Services, San Diego, CA; Journey Recovery Chemical Dependency Treatment Program, Billings, Montana; East Bay Community Recovery Project, Hayward, CA

Summary: (To include basic study design, measures, results, and notable limitations)
The purpose of the study was to compare the Matrix Model [now called Matrix Model Intensive Outpatient Program], a manualized treatment method, with treatment-as-usual (TAU) in eight community outpatient settings in the Western United States. Participants were randomly assigned to receive either treatment as usual (TAU) or a manualized 16-week treatment (Matrix Model for Adults). Measures utilized include the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) MA-dependence checklist, the Addiction Severity Index (ASI; fifth edition), as well as weekly urine samples. Results indicate that participants in the Matrix Model for Adults condition provided more MA-negative urine samples during the treatment period across all but the drug-court site. In overall analyses, the Matrix Model for Adults approach showed better treatment retention and program completion than the TAU condition. However, at discharge and 6-month follow-up, participants in both conditions demonstrated nearly a threefold reduction in mean days of MA use from baseline; the intreatment superiority of the Matrix Model for Adults approach was not demonstrated at post-treatment measurement points. Limitations include TAU condition was site-specific and varied widely between sites, and variation in program length provided another major analytical hurdle.

Length of controlled postintervention follow-up: 2–8 months (16 weeks/4 months of Matrix Model for Adults treatment; 6 and 12-month follow-ups post-admission).

Wolitzky-Taylor, K., Sewart, A., Karno, M., Ries, R., & Stimson, J. (2022). Development and initial pilot testing of a fully integrated treatment for comorbid social anxiety disorder and alcohol use disorder in a community-based SUD clinic setting. Behaviour Research and Therapy, 148, Article 103999. https://doi.org/10.1016/j.brat.2021.103999

Type of Study: Randomized controlled trial
Number of Participants: 56

Population:

• Age — Mean=40.27 years
• Race/Ethnicity — 43% White, 23% Hispanic/Latinx, 14% multiracial or Other Race/Ethnicity, 11% Black/African-American, 7% Asian/Asian-American/Pacific Islander, and 2% Native American
• Gender — 53% Female
• Status — Participants were individuals with social anxiety disorder (SAD) and alcohol use disorder (AUD).

Location/Institution: CLARE/Matrix clinic, California

Summary: (To include basic study design, measures, results, and notable limitations)
The purpose of the study was to develop and evaluate a novel treatment protocol that delivers psychosocial treatment for social anxiety disorder (SAD) and alcohol use disorder (AUD) together in one intervention. Participants were randomized to either usual care (UC), consisting of the Matrix Model of Addiction IOP (intensive outpatient program) [now called Matrix Model Intensive Outpatient Program]; or the Fully Integrated Treatment (FIT) for comorbid SAD and AUD IOP. Measures utilized include the Social Phobia Inventory (SPIN), the AUDIT, the MINI Neuropsychiatric Interview, the Liebowitz Social Anxiety Scale-Self Report (LSAS-SR), the Drinking to Cope with Social Anxiety Scale (DCSAS), the Timeline Followback (TLFB), and the Short Inventory of Problems (SIP). Results indicate that by the 6-month follow-up, those in FIT showed superior improvement to Matrix Model of Addiction IOP on number of drinking days in the past 30 days and social anxiety severity at follow-up, but there were no differences between groups on quantity of alcohol consumed on drinking days. Alcohol-related problems improved in both groups, with no statistically significant differences. Within-group improvement was observed in FIT (but not in Matrix Model of Addiction IOP) on drinking to cope with social anxiety and avoidance of social situations without alcohol, but between-group effects were non-significant. In sum, the integrated treatment of SAD and AUD led to greater reductions in both the frequency of drinking and in social anxiety symptoms than usual care. Limitations include small sample size, and attrition.

Length of controlled postintervention follow-up: 6 months.