Long-term Behavior Change - 1

Not Applicable

Completed

Conditions: Amphetamine-related Disorders

Interventions: Behavioral: contingency management voucher

Registration Number: NCT00158197

Lead Sponsor: Friends Research Institute, Inc.

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

Status: COMPLETED

Sex: All

Target Recruitment: 119

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
intermittent unpredictable schedule	contingency management voucher	Those in the intermittent unpredictable condition will be eligible to receive a contingency management voucher on one day a week. Participants in this group will receive a voucher for $22.00 following their first 3 methamphetamine-negative urine tests. They will then be eligible to receive a voucher one day a week if all of their urine tests since the receipt of their last voucher were methamphetamine negative. They will receive a voucher for $35.50 for the provision of their second set of 3 consecutive instances of methamphetamine-negative urine samples, $49.00 for their third set of 3 consecutive instances, and so forth. The day of the week on which the voucher will be available will be randomly selected for each week and the participants will not know which day of the week they will be eligible to receive a voucher until they have provided their urine test. All participants will provide observed urine samples M, W, \& F for 12 wks and complete measures 1x/wk.
continuous voucher schedule	contingency management voucher	Those in the continuous condition will receive a contingency management voucher each time they test negative for methamphetamine. The initial voucher value will be $2.50. Each consecutive instance of abstinence will increase the magnitude of the voucher by $1.50. Three consecutive abstinences will result in the delivery of a $10.00 bonus. Provision of a methamphetamine-positive urine sample, or failure to test, will result in a reset in the voucher magnitude back to its original level from whence the progression can begin again. All participants will provide observed urine samples three times a week (e.g., M, W, \& F) for twelve weeks and will complete study-related measures one time per week.
intermittent predictable schedule	contingency management voucher	Those in the intermittent predictable condition will earn a contingency management voucher when they provide three consecutive methamphetamine-negative urine tests. Participants in the intermittent predictable condition will receive $22.00 for the provision of their first three consecutive methamphetamine-negative urine samples, $35.50 for the provision of their second set of three consecutive instances of methamphetamine-negative urine samples, and so forth. There are no bonuses for consecutive instances of abstinence in the intermittent predictable condition. Provision of a methamphetamine-positive urine sample, or failure to test, will result in a reset in the voucher magnitude back to its original level from whence the progression can begin again. All participants will provide observed urine samples three times a week (e.g., M, W, \& F) for twelve weeks and will complete study-related measures one time per week.

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