Long-term Behavior Change - 1

Not Applicable

Completed

Brief Summary: The purpose of this study is to determine if different reinforcement procedures (i.e., schedules) produce different patterns of long-term abstinence from methamphetamine. We anticipate that the three contingency management conditions will promote longer periods of abstinence in the year following treatment relative to the standard control group. Furthermore, we predict that the intermittent reinforcement procedures will produce longer periods of continued abstinence (i.e., long-term behavior change) in the year following treatment than the continuous reinforcement procedure. Finally, we predict that the intermittent unpredictable schedule will produce longer lasting behavior change than the intermittent predictable schedule. Methamphetamine use will be measured using urine toxicology and self-report of methamphetamine use.

Detailed Description: Briefly the four study conditions are: (1) standard treatment which consists of 16 weeks of psychosocial treatment, (2) continuous contingency management which consists of 16 weeks of psychosocial treatment with a contingency management procedure in effect during the first twelve weeks in which vouchers are made available after each provision of a methamphetamine-negative urine test, (3) intermittent predictable contingency management which consists of 16 weeks of psychosocial treatment with a contingency management procedure in effect during the first twelve weeks in which vouchers are available after the provision of every three consecutive methamphetamine-negative urine samples, and (4) intermittent unpredictable contingency management which consists of 16 weeks of psychosocial treatment with a contingency management procedure in effect during the first twelve weeks in which vouchers are available on one day each week (randomly selected after the first week) for the provision of methamphetamine-negative urine samples provided all urine samples since delivery of the last reinforcer were also methamphetamine negative.

Recruitment & Eligibility

Inclusion Criteria

Meet Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for methamphetamine dependence
Willing and able to comply with study procedures
Willing and able to provide written informed consent

Exclusion Criteria

Have a medical condition that, in the study Principal Investigator (PI's) judgment, might interfere with safe study participation
Have a recent (past 30 days) history of suicide attempts and/or current serious suicidal intention or plan as assessed by the Beck Depression Inventory (BDI)
Have a history of violent criminal behavior or be on parole
Any other circumstances that, in the opinion of the PI, would interfere with safe study participation

Primary Outcome Measures

Name	Time	Method
Methamphetamine Use During Intervention	3x/week for 16 weeks	Drug use measured by urine toxicology conducted by on site Enzyme-multiplied immunoassay technique (EMIT) assay over time.
Methamphetamine Use, Measured by Number of Consecutive Days of Abstinence	16 Weeks	Drug use measured by urine toxicology conducted by on site EMIT assay and added up to obtain how many days of consecutive abstinence were observed for each individual
Methamphetamine Use, Follow-Up	1x/month for 4 months	Drug use measured by urine toxicology conducted by on site EMIT assay over time

Secondary Outcome Measures

Name	Time	Method

Locations (1): Friends Research Institute
🇺🇸
Rancho Cucamonga, California, United States
Friends Research Institute
🇺🇸Rancho Cucamonga, California, United States