Rapid trace element analysis of microgram soft materials with cryogenic milling and laser ablation spectroscopy.

Trace element analysis of soft materials, to determine the content of low concentration elements, is important in many industries such as food quality control and medical biopsy analysis. Many of these applications would benefit from faster analysis with smaller sample requirements. Further, some natural samples are soft and have high water content, which brings challenges to element analysis. Here, we develop a cryogenic pelletization pretreatment to address those challenges. The soft samples are cryogenically milled, freeze-dried, and pelletized before elemental analysis. Analysis is performed by laser ablation spectroscopy, the combination of laser-induced breakdown spectroscopy (LIBS) and laser ablation inductively coupled plasma mass spectroscopy (LA-ICP-MS), to rapidly analyze light and heavy analytes. For this initial study, aluminum (Al) content in soft samples is determined by LIBS and lead (Pb) content by LA-ICP-MS. The standard addition method is performed to build calibration curves for element quantification. The measurements are compared with a Hong Kong government certified acid digestion and ICP-MS procedure. The experiment is performed on standard reference materials and selected food samples. The relative errors compared with certified measurements are less than 10% for all samples, with Al content ranging from 63-1466 µg/g and Pb content from 0.37-2.35 µg/g (dry mass). Microscopy of pellets shows that laser ablation spectroscopy can be performed with 100 µg of sample (dry mass). Total analysis time from raw sample to final measurement, including preparation, is under 1 h. The results indicate that the laser ablation spectroscopy with cryogenic pelletization is a promising technique for many applications such as screening of small food samples for toxic metals and trace element analysis of millimeter biopsies.

Proof-of-Concept Study to Assess the Nociceptin Receptor Antagonist LY2940094 as a New Treatment for Alcohol Dependence.

BACKGROUND: This was a proof-of-concept study to evaluate the efficacy of LY2940094, a nociceptin/orphanin FQ peptide receptor antagonist, in reducing alcohol consumption in actively alcohol-drinking patients with alcohol dependence. METHODS: Eighty-eight patients, 21 to 66 years of age, diagnosed with alcohol dependence, reporting 3 to 6 heavy drinking days per week, were randomized (1:1) to 8 weeks of treatment with once-daily oral placebo (N = 44) or 40 mg/d of LY2940094 (N = 44). The primary efficacy analysis was the change from baseline in number of drinks per day (NDD) utilizing mixed-model repeated measures comparing LY2940094 and placebo in Month 2 of the 8-week double-blind treatment period. The probability that the difference relative to placebo in NDD was ≤0 at endpoint was calculated, and a probability ≥80% was considered to be evidence that LY2940094 was associated with the reduction in NDD. RESULTS: After 8 weeks of treatment, reduction in mean NDD did not differ between LY2940094 versus placebo (-1.4 vs. -1.5, respectively, 44% probability of greater reduction relative to placebo), but there was a greater reduction in the mean percentage of heavy drinking days in a month with LY2940094 versus placebo (-24.5 vs. -15.7%, respectively, 93% probability of a greater reduction relative to placebo), and an increase in the mean percentage of abstinent days in a month compared to placebo (9.1 vs. 1.9%, respectively, 91% probability of a greater increase relative to placebo). Patients who were treated with LY2940094 showed decreased plasma levels of gamma-glutamyl transferase with probabilities ≥98% for greater reduction compared with placebo at Weeks 1, 4, 6, and 8. Treatment-emergent adverse events in ≥5% of patients treated with LY2940094 included insomnia, vomiting, and anxiety. There were no serious adverse events or significant changes in laboratory assessments or vital signs with LY2940094. CONCLUSIONS: Although not reducing the NDD, LY2940094, compared to placebo, did reduce heavy drinking days and increased abstinence days in patients with alcohol dependence.

A Novel, Orally Bioavailable Nociceptin Receptor Antagonist, LY2940094, Reduces Ethanol Self-Administration and Ethanol Seeking in Animal Models.

BACKGROUND: The nociceptin/orphanin-FQ (or opioid receptor-like [ORL1]) receptor (NOP) is localized in the mesolimbic reward pathway and has been suggested to play a role in feeding, mood, stress, and addiction. Since its deorphanization in 1995, there has been a clear dichotomy in the literature regarding whether an agonist or antagonist would provide therapeutic benefit. Specifically, the literature reports indicate that NOP receptor antagonists produce efficacy in animal models of hyperphagia and antidepressant-like activity, whereas NOP agonists produce anxiolytic-like effects and dampen reward/addiction behaviors including ethanol consumption. METHODS: We characterize here the potent, orally bioavailable NOP antagonist, LY2940094, in rodent models of ethanol consumption, including ethanol self-administration, progressive ratio operant self-administration, stress-induced reinstatement of ethanol seeking, and in vivo microdialysis in the nucleus accumbens. RESULTS: LY2940094 dose dependently reduced homecage ethanol self-administration in Indiana alcohol-preferring (P) and Marchigian Sardinian alcohol-preferring (msP) rats, without affecting food/water intake or locomotor activity. Reduced ethanol intake in P rats did not show significant tolerance over 4 days of subchronic dosing. LY2940094 attenuated progressive ratio operant responding and break points for ethanol in P rats. Moreover, stress-induced reinstatement of ethanol seeking in msP rats was completely blocked by LY2940094. Furthermore, LY2940094 blocked ethanol-stimulated dopamine release in response to ethanol challenge (1.1 g/kg, intraperitoneally). CONCLUSIONS: Our findings demonstrate for the first time that blockade of NOP receptors attenuates ethanol self-administration and ethanol-motivated behaviors, stress-induced ethanol seeking, and ethanol-induced stimulation of brain reward pathways in lines of rats that exhibit excessive ethanol consumption. Results suggest that LY2940094 may have potential therapeutic utility in treating alcohol addiction.

Determining pharmacological selectivity of the kappa opioid receptor antagonist LY2456302 using pupillometry as a translational biomarker in rat and human.

BACKGROUND: Selective kappa opioid receptor antagonism is a promising experimental strategy for the treatment of depression. The kappa opioid receptor antagonist, LY2456302, exhibits ~30-fold higher affinity for kappa opioid receptors over mu opioid receptors, which is the next closest identified pharmacology. METHODS: Here, we determined kappa opioid receptor pharmacological selectivity of LY2456302 by assessing mu opioid receptor antagonism using translational pupillometry in rats and humans. RESULTS: In rats, morphine-induced mydriasis was completely blocked by the nonselective opioid receptor antagonist naloxone (3mg/kg, which produced 90% mu opioid receptor occupancy), while 100 and 300 mg/kg LY2456302 (which produced 56% and 87% mu opioid receptor occupancy, respectively) only partially blocked morphine-induced mydriasis. In humans, fentanyl-induced miosis was completely blocked by 50mg naltrexone, and LY2456302 dose-dependently blocked miosis at 25 and 60 mg (minimal-to-no blockade at 4-10mg). CONCLUSIONS: We demonstrate, for the first time, the use of translational pupillometry in the context of receptor occupancy to identify a clinical dose of LY2456302 achieving maximal kappa opioid receptor occupancy without evidence of significant mu receptor antagonism.

A phase 2, placebo-controlled study of the opioid receptor antagonist LY2196044 for the treatment of alcohol dependence.

BACKGROUND: Endogenous opioid-mediated reward pathways may play a role in the development and maintenance of alcohol dependence. This study tested whether LY2196044, an opioid receptor antagonist, in combination with medical management would reduce drinking in alcohol-dependent patients. METHODS: This was a multicenter, outpatient, randomized, double-blind, parallel, and placebo-controlled trial with a 16-week treatment period. Patients (N = 375) were alcohol-dependent, treatment-seeking adults. Patients were randomly assigned to once-daily LY2196044 (final doses of 125 or 250 mg/d) or placebo. DNA samples were collected at baseline. At each visit, patients underwent safety assessments, laboratory testing, efficacy measures, and medical management. Blood samples were also obtained for pharmacokinetic testing. The primary measure was the change from baseline in the percent heavy drinking days (HDD). Secondary efficacy measures were percent days abstinent per month and number of drinks per day. RESULTS: The treatment difference in change from baseline in % HDD between LY2196044 and placebo was not statistically significant (-43.02 vs. -38.72%, respectively; p = 0.12). There was a trend toward greater change from baseline in the percent days abstinent per month for the LY2196044 group compared with the placebo group (33.49 vs. 28.12%, respectively; p = 0.051). The decrease from baseline for mean number of drinks per day was statistically significantly greater in the LY2196044 group compared with the placebo group (-5.37 vs. -4.66 drinks per day, respectively; p = 0.013). LY2196044-treated patients who were dopamine receptor type 4-variable number tandem repeat L carriers had greater reductions in % HDD (p = 0.0565), increased percent days abstinent (p = 0.0496), and reduced drinks per day (p = 0.0069) than placebo-treated L carriers. The safety profile for LY2196044 appeared similar to that of other opioid antagonists. CONCLUSIONS: The results from this proof-of-concept clinical trial warrant further evaluation of LY2196044 for the treatment of alcohol dependence.

A randomized clinical trial of a Therapeutic Workplace for chronically unemployed, homeless, alcohol-dependent adults.

AIMS: To assess the efficacy of the Therapeutic Workplace, a substance abuse intervention that promotes abstinence while simultaneously addressing the issues of poverty and lack of job skills, in promoting abstinence from alcohol among homeless alcoholics. METHODS: Participants (n = 124) were randomly assigned to conditions either requiring abstinence from alcohol to engage in paid job skills training (Contingent Paid Training group), offering paid job skills training with no abstinence contingencies (Paid Training group) or offering unpaid job skill training with no abstinence contingencies (Unpaid Training group). RESULTS: Participants in the Contingent Paid Training group had significantly fewer positive (blood alcohol level ≥ 0.004 g/dl) breath samples than the Paid Training group in both randomly scheduled breath samples collected in the community and breath samples collected during monthly assessments. The breath sample results from the Unpaid Training group were similar in absolute terms to the Contingent Paid Training group, which may have been influenced by a lower breath sample collection rate in this group and fewer reported drinks per day consumed at intake. CONCLUSION: Overall, the results support the utility of the Therapeutic Workplace intervention to promote abstinence from alcohol among homeless alcoholics, and support paid training as a way of increasing engagement in training programs.

Economic cost of the therapeutic workplace intervention added to methadone maintenance.

Therapeutic workplace is a novel intervention that uses access to paid training and employment to reinforce drug abstinence within the context of standard methadone maintenance. We used the Drug Abuse Treatment Cost Analysis Program as a standard method of estimating the economic costs of this intervention. In a 1-year period, the therapeutic workplace served 122 methadone maintenance clients who had a median length of stay of 22 weeks. The workplace maintained a mean daily census of 48 clients. The combined cost of methadone maintenance and the therapeutic workplace was estimated at US$362 per week. This cost is less than that of other treatments that might be used to promote abstinence in individuals who continue to use drugs during methadone treatment. Given prior evidence of effectiveness, these cost data may be useful to policy makers, social service agencies, and researchers interested in using or further developing the therapeutic workplace intervention.

Attendance rates in a workplace predict subsequent outcome of employment-based reinforcement of cocaine abstinence in methadone patients.

This study assessed whether attendance rates in a workplace predicted subsequent outcome of employment-based reinforcement of cocaine abstinence. Unemployed adults in Baltimore methadone programs who used cocaine (N=111) could work in a workplace for 4 hr every weekday and earn $10.00 per hour in vouchers for 26 weeks. During an induction period, participants provided urine samples but could work independent of their urinalysis results. After the induction period, participants had to provide urinalysis evidence of cocaine abstinence to work and maintain maximum pay. A multiple regression analysis showed that induction period attendance was independently associated with urinalysis evidence of cocaine abstinence under the employment-based abstinence reinforcement contingency. Induction period attendance may measure the reinforcing value of employment and could be used to guide the improvement of employment-based abstinence reinforcement.

HIV Sexual Risk Behaviors among Ketamine and Non-Ketamine Using Criminal Offenders Prior to Prison Entry.

This study is the first to examine ketamine use and its association with HIV sexual risk behaviors among a criminal offending population in the United States. Data were collected from 716 inmates as part of the Transitional Case Management (TCM) protocol within the Criminal Justice Drug Abuse Treatment Studies (CJ-DATS) cooperative agreement. Bivariate analyses were used to identify differences between ketamine users (n=44) and non-ketamine users (n=672). Three Poisson regression models were used to identify the significant correlates of high risk sexual behaviors in the 30 days prior to incarceration-- (1) number of times had unprotected sex while high, (2) number of times had unprotected vaginal sex, and (3) number of times had unprotected anal sex. Results indicate that ketamine was a significant correlate in all of the Poisson regression models. Findings add to the literature and indicate that ketamine use may be a marker for engaging in HIV risk behaviors among criminal offenders.

A randomized trial of employment-based reinforcement of cocaine abstinence in injection drug users.

High-magnitude and long-duration abstinence reinforcement can promote drug abstinence but can be difficult to finance. Employment may be a vehicle for arranging high-magnitude and long-duration abstinence reinforcement. This study determined if employment-based abstinence reinforcement could increase cocaine abstinence in adults who inject drugs and use cocaine during methadone treatment. Participants could work 4 hr every weekday in a workplace where they could earn about $10.00 per hour in vouchers; they were required to provide routine urine samples. Participants who attended the workplace and provided cocaine-positive urine samples during the initial 4 weeks were invited to work 26 weeks and were randomly assigned to an abstinence-and-work (n = 28) or work-only (n = 28) group. Abstinence-and-work participants had to provide urine samples showing cocaine abstinence to work and maintain maximum pay. Work-only participants could work independent of their urinalysis results. Abstinence-and-work participants provided more (p = .004; OR = 5.80, 95% CI = 2.03-16.56) cocaine-negative urine samples (29%) than did work-only participants (10%). Employment-based abstinence reinforcement can increase cocaine abstinence.

An intensive assessment of alcohol use and emergency department utilization in homeless alcohol-dependent adults.

BACKGROUND: Excessive alcohol use among the homeless may contribute to their high rates of emergency department use. Survey-based studies have provided some information on the relation between alcohol and emergency department use among the homeless. METHODS: This study used an intensive schedule of random breath collections and self-report assessments to examine the relation between emergency department utilization and alcohol use in homeless alcohol-dependent adults. Data were from homeless alcohol-dependent adults (N=116) who were participating in a therapeutic workplace that provided job-skills training every weekday for 26 weeks. Breath-sample collections and assessments of self-reported alcohol use were scheduled each week, an average of twice per week per participant, at random times between 9:00 A.M. and 5:00 P.M. Participants received $35 for each breath sample collected. Self-reports of emergency department use were assessed throughout the study. RESULTS: Thirty-four percent of participants reported attending an emergency department and reported an average of 2.2 emergency department visits (range 1-10 visits). Alcohol intoxication was the most common reason for emergency department use. Participants who used the emergency department had significantly more alcohol-positive breath samples and more self-reported heavy alcohol use than participants who did not use the emergency department. CONCLUSIONS: This study provided a rare intensive assessment of alcohol and emergency department use in homeless alcohol-dependent adults over an extended period. Emergency department use was high and was significantly related to indices of alcohol use.

A randomized controlled trial of the therapeutic workplace for community methadone patients: a partial failure to engage.

The Therapeutic Workplace is an employment-based treatment for drug addiction that uses wages for work to reinforce drug abstinence. The Therapeutic Workplace has promoted abstinence from heroin and cocaine in treatment-resistant mothers in methadone treatment. This study attempted to replicate that effect in crack cocaine users recruited from community-based methadone programs. Participants were randomly assigned to a Therapeutic Workplace (n=22) or usual care control (n=25) group. Therapeutic Workplace participants were invited to work in the workplace and earn vouchers every weekday for 9 months contingent on documented opiate and cocaine abstinence. The two groups did not differ significantly on measures of cocaine or opiate use collected during study participation. Daily attendance and urinalysis results of the Therapeutic Workplace group were analyzed, and only 7 of the 22 participants initiated consistent periods of abstinence and workplace attendance. Two individuals gained access to the workplace on a few days, and 9 participants attempted to gain access to the workplace but never provided a drug-negative urine sample. Possible reasons for differences between the current study and the previous Therapeutic Workplace study are considered. Procedures that increase participant contact with the Therapeutic Workplace and its reinforcement contingencies might increase the likelihood of these individuals being successful in the treatment program.

Behavioral factors predicting response to employment-based reinforcement of cocaine abstinence in methadone patients.

We sought to identify behavioral factors associated with response to an employment-based intervention, in which participants had to provide drug-free urine samples to gain access to paid employment. The present secondary analysis included data from a randomized clinical trial. The trial evaluated whether employment-based reinforcement could decrease cocaine use in community methadone patients. Participants (N=56) in the trial worked in a model workplace for 4 hr every weekday and earned about $10 per hr. After a 4-week baseline, participants were randomly assigned to an Abstinence & Work (n = 28) or Work Only (n = 28) condition and could work for an additional 26 weeks. Abstinence & Work participants had to provide cocaine-negative urine samples to work and maintain maximum pay. Work Only participants only had to work to earn pay. For Work Only participants, cocaine abstinence during baseline and the intervention period were significantly (rs = .72, p <.001) correlated. For Abstinence & Work participants, baseline opiate abstinence was significantly correlated (rs = .59, p <.001) and workplace attendance was marginally correlated (rs = .32, p = .098) with cocaine abstinence during the intervention period. Furthermore, participants who provided over 60% cocaine-negative urine samples during the intervention period (i.e., responders) had significantly higher baseline rates of opiate abstinence (p <.0001) and workplace attendance (p = .042) than non-responders. Employment-based reinforcement of cocaine abstinence may be improved by increasing opiate abstinence and workplace attendance prior to initiating the cocaine-abstinence intervention.

Community reinforcement therapy for cocaine-dependent outpatients.

OBJECTIVE: To examine the contributions of community reinforcement therapy to outcome in the community reinforcement approach (CRA) + vouchers outpatient treatment for cocaine dependence. METHODS: One hundred cocaine-dependent outpatients were randomly assigned to one of 2 treatment conditions: CRA + vouchers or vouchers only. All patients earned incentives in the form of vouchers exchangeable for retail items contingent on cocaine-free urinalysis results during treatment weeks 1 to 12. Incentives were combined with a 24-week course of CRA therapy designed to promote healthy lifestyle changes in the CRA + vouchers condition, while incentives represented the primary treatment in the vouchers-only condition. Patient drug use and psychosocial functioning were assessed at intake and at least every 3 months for 2 years after treatment entry. RESULTS: Patients treated with CRA + vouchers were retained better in treatment, used cocaine at a lower frequency during treatment but not follow-up, and reported a lower frequency of drinking to intoxication during treatment and follow-up compared with patients treated with vouchers only. Patients treated with CRA + vouchers also reported a higher frequency of days of paid employment during treatment and the initial 6 months of follow-up, decreased depressive symptoms during treatment only, and fewer hospitalizations and legal problems during follow-up. CONCLUSIONS: Combining CRA with vouchers had therapeutic effects on substance abuse and psychosocial functioning during treatment and posttreatment follow-up in cocaine-dependent outpatients, although effects on cocaine use appear to be limited to the treatment period.

Reinforcement-based therapy: 12-month evaluation of an outpatient drug-free treatment for heroin abusers.

This controlled study examined the efficacy of reinforcement-based therapy (RBT) for producing enhanced abstinence outcomes over 12 months in opioid-dependent patients exiting a brief residential detoxification. Patients were randomly assigned upon completing their medically managed taper (i.e., detoxification) to RBT (N=66) or usual care (N=64) referral to community treatment programs. The 6-month RBT program offered an array of abstinence-based incentives including rent payment for recovery housing, program-led recreational activities and skills training for procuring employment. RBT produced significantly higher self-report and urinalysis-confirmed rates of abstinence from opioids and cocaine relative to usual care at 1 (42% versus 15%) and 3 (38% versus 17%) months during treatment but not at 6 or 12 months after enrollment. The RBT but not the usual care group showed significant increases in the number of days worked and the amount of legal income earned at 3, 6 and 12 months. The results of this randomized study suggest that an intensive reinforcement-based therapy that includes abstinence-based recovery housing is a promising approach; however, further research is needed to determine the role of treatment intensity and the specific efficacy of RBT's component parts.

A web-based therapeutic workplace for the treatment of drug addiction and chronic unemployment.

This article describes a Web-based therapeutic workplace intervention designed to promote heroin and cocaine abstinence and train and employ participants as data entry operators. Patients are paid to participate in training and then to perform data entry jobs in a therapeutic workplace business. Salary is linked to abstinence by requiring patients to provide drug-free urine samples to gain access to the workplace. Prior data show that a prototype of the intervention could promote drug abstinence. Preliminary data on the Web-based intervention suggest that it should be able to teach adults with histories of chronic unemployment and drug addiction to become skilled data entry operators in about 3 to 6 months. Early experience in the business provides preliminary evidence that it might become financially successful. The therapeutic workplace intervention may serve as an effective and practical long-term treatment for chronic unemployment and heroin and cocaine addiction.

Evaluation of an injection depot formulation of buprenorphine: placebo comparison.

AIMS: Buprenorphine is a mu-opioid partial agonist that is marketed in a sublingual formulation as a treatment for opioid dependence. A microcapsule depot sustained-release formulation has been developed which may offer effective treatment of opioid dependence while also minimizing risks of illicit diversion or patient non-compliance. The present study examined the efficacy of depot buprenorphine in suppressing the opioid withdrawal syndrome and in attenuating the effects of exogenous opioid challenge. DESIGN: A placebo-controlled, double-blind, randomized trial. SETTING: A closed residential research facility. PARTICIPANTS: A total of 15 opioid-dependent participants were enrolled into the 6-week study. INTERVENTION: Fifteen participants were randomized to receive a single subcutaneous depot injection containing buprenorphine (58 mg) or placebo. Two participants, both of whom received placebo, terminated participation after depot administration. Thirteen participants (six buprenorphine, seven placebo) completed the 6-week study and were assessed throughout the study for signs and symptoms of opioid withdrawal and for response to weekly subcutaneous challenges with 3 mg hydromorphone. MEASUREMENT: Subjective, physiological and observer-rated indices of opioid withdrawal and opioid agonist effects. FINDINGS: Depot buprenorphine provided more effective relief from opioid withdrawal than placebo, as evidenced by significantly fewer buprenorphine participants requiring supplemental medications for withdrawal suppression after depot administration compared to participants receiving placebo. In the weekly hydromorphone challenge sessions, depot buprenorphine significantly reduced opioid response on measures of subjective effects and pupillary diameter. CONCLUSIONS: Results from this double-blind, placebo-controlled study indicate that depot buprenorphine is effective in providing both withdrawal suppression and opioid blockade. Future studies examining additional doses and repeated dosing regimens with depot buprenorphine are warranted.

Evaluation of a modified contingency management intervention for consistent attendance in therapeutic workplace participants.

In a therapeutic workplace business, drug abuse patients are hired as data entry operators and paid to perform data entry work contingent upon documented drug abstinence. Reliable attendance has been difficult to maintain despite the opportunity for operators to earn a living wage, 6 h per day, 5 days per week. A within-subject reversal design experiment evaluated a contingency management intervention that allowed for flexibility regarding when operators could arrive to work, yet maintained a contingency for reliable workplace attendance. Results from a within-subject reversal design experiment demonstrated the contingency management intervention to be effective in increasing the frequency of completed work shifts in four of five operators. Repeated measures ANOVA and Tukey's post-hoc tests of grouped data showed that the contingency management intervention significantly (P < 0.05) increased the mean percent of days that operators completed work shifts (5% baseline; 63% contingency management; 7% baseline). This study demonstrates an effective procedure for maintaining attendance in therapeutic workplace participants.

Contingency management of reliable attendance of chronically unemployed substance abusers in a therapeutic workplace.

The Therapeutic Workplace is an effective drug abuse treatment that integrates abstinence reinforcement into a work setting by using a salary that drug abusers earn for work. Drug abuse patients are trained and hired to become data entry operators in a Therapeutic Workplace business. Despite the opportunity to earn a high wage, participants frequently arrive at work late and fail to work complete shifts. In the present study, a contingency management intervention to promote consistent and reliable attendance was evaluated in 4 participants. Participants were not allowed to work on days that they arrived late, and their pay was temporarily reduced each time they arrived late at work or failed to complete a work shift. A within-subject reversal design showed that the intervention increased the frequency with which participants arrived at work on time and completed work shifts.

Effects of reinforcer magnitude on data-entry productivity in chronically unemployed drug abusers participating in a Therapeutic Workplace.

The Therapeutic Workplace is a substance abuse treatment wherein patients are hired and paid to work in a job contingent on daily drug-free urine samples. The present study examined data-entry productivity of 6 unemployed methadone patients who demonstrated relatively variable and low data-entry response rates. A within-subject reversal design was used to determine whether increasing reinforcement magnitude tenfold could increase response rates. Four of the 6 participants showed the highest rates of responding in the high magnitude reinforcement condition. Two participants, who had the lowest overall response rates, showed less robust changes to the magnitude manipulation. The results suggest that reinforcement magnitude can be used to improve productivity in Therapeutic Workplace participants.