Skip to main content
NCBI home page
NIHPA Author Manuscripts logoLink to NIHPA Author Manuscripts
. Author manuscript; available in PMC: 2015 Jan 27.
Published in final edited form as: J Vocat Rehabil. 2015 Jan 13;42(1):67–74. doi: 10.3233/JVR-140724

Academic skills of chronically unemployed drug-addicted adults

August F Holtyn 1, Anthony DeFulio 1, Kenneth Silverman 1,*
PMCID: PMC4307804  NIHMSID: NIHMS647767  PMID: 25635162

Abstract

BACKGROUND

The strong association between unemployment and drug addiction suggests that employment interventions are an important and needed focus of drug-addiction treatment. The increasing necessity of possessing basic academic skills to function in the workplace may require that some individuals receive educational training along with vocational training.

OBJECTIVE

This study investigated the academic skills of drug-addicted and chronically-unemployed adults (N = 559) who were enrolled in one of six studies conducted at the Center for Learning and Health in Baltimore, MD.

METHODS

Upon study enrollment, academic skills in math, spelling, and reading were examined using the Wide Range Achievement Test (WRAT-3 or WRAT-4) and educational history was examined using the Addiction Severity Index–Lite.

RESULTS

Although participants completed an average of 11 years of education, actual academic skill level was at or below the seventh grade level for 81% of participants in math, 61% in spelling, and 43% in reading, and most participants were classified as Low Average or below based on age group norms. Despite the fact that participants in this analysis were studied across several years and were from diverse populations, rates of high school completion and academic skill levels were remarkably similar.

CONCLUSIONS

Programs designed to improve the long-term employment status of drug-addicted individuals may benefit from the inclusion of basic adult education; future research on the topic is needed. Although establishing basic skills does not directly address chronic unemployment, it may help individuals obtain the jobs they desire and function effectively in those jobs.

Keywords: Academic skills, vocational training, employment, education, poverty, drug addiction, Therapeutic Workplace

1. Introduction

Employment is recognized as an important factor in the treatment of drug addiction. Individuals who are unemployed have higher rates of substance abuse than those who are regularly employed, unemployment is common among individuals in substance abuse treatment, and poorer treatment outcomes (e.g., treatment attrition, more drug use during treatment, higher rates of relapse) are associated with unemployment (Ginexi, Foss, & Scott, 2003; Kidorf, Stitzer, Brooner, & Goldberg, 1994; Platt, 1995; Sterling et al., 2001). Employment is frequently cited as a goal of drug-addiction treatment as many clinicians believe it plays a vital role in recovery (Magura, 2003; Magura, Staines, Blankertz, & Madison, 2004). However, standard drug-addiction treatments rarely result in increased rates of employment (Magura et al., 2004; Hubbard, Craddock, & Anderson, 2003; Schildhaus, Gerstein, Brittingham, Cerbone, & Dugoni, 2000). Providing employment interventions in conjunction with drug-addiction treatment may be necessary to promote job-seeking, employment, and retention (Magura, 2003).

Existing employment interventions can be broadly separated into two main categories, “quick-entry” and “intensive education and training.” The quick-entry approach emphasizes job-search, job-interview skills, and quick entry into the job market, as participants are encouraged to seek jobs that match their current skill level. Although quick-entry programs have had some success in placing individuals in jobs, many do not benefit from these interventions (Hamilton et al., 2001). For example, the NIDA Clinical Trials Network conducted a randomized trial comparing a quick-entry program for drug-addicted adults called the Job Seekers’ Workshop to a standard care group. The Job Seekers’ Workshop participants and standard care participants had low and similar rates of employment at 12- (20% and 24%, respectively, were employed) and 24-week (31% and 32%, respectively) follow-ups (Svikis et al., 2012). A potential reason for the limited success of quick-entry programs may be because of an incongruity between job interests and skills of the jobseekers. Silverman, Chutuape, Svikis, Bigelow, & Stitzer (1995), for example, examined the occupational interests and academic skills of 50 drug-addicted women and found that most participants desired jobs that were beyond their education and training.

The intensive education and training (also known as “human capital development”) approach focuses on the development of academic and job-related skills needed to obtain higher-paying jobs. These may include basic academic skills training, General Education Development (GED) test preparation, vocational training, or a combination (Hamilton et al., 2001). Intensive education and training programs appear promising. In a randomized controlled study of “education-focused” programs for adult welfare recipients, secondary analyses showed that participants who were consistently engaged in the educational programs showed improvements in basic literacy and math skills, increased attainment of GEDs, and increased employment earnings (Bos, Scrivener, Snipes, & Hamilton, 2002; Hamilton, 2002). Intensive education and training approaches could be an ideal means to improve the lives of poorly educated and low-income populations, since increasing education appears to increase income. Data from the U.S. Census Bureau shows that lifetime income increases progressively as adults achieve higher levels of education (Bauman & Ryan, 2001; Day & Newburger, 2002). Indeed, education has been shown to be strongly correlated with employment earnings and status (Psacharopoulos, 1994; Psacharopoulos & Patrinos, 2004); educated individuals earn higher wages and experience less unemployment than their less-educated counterparts. In an effort to use resources efficiently, there is a pressing need to determine who would benefit most from employment interventions that incorporate adult education programs (Hamilton et al., 2002).

The present analysis was conducted to assess the educational and academic skill levels of drug-addicted individuals who have a history of chronic unemployment, and determine the potential utility of including adult education programs in the context of substance abuse treatment. Data were from participants enrolled in an employment-based treatment intervention for drug addiction and unemployment called the therapeutic workplace. The therapeutic workplace is part of a larger family of voucher-based reinforcement interventions that have been used effectively in the treatment of drug addiction (Higgins & Silverman, 2008). Specifically, participants enrolled in the therapeutic workplace are invited to work for 4 hours every weekday for 6 months or more and are paid about $10 per hour for working. The therapeutic workplace arranges employment-based reinforcement contingencies in which participants are required to engage in target behaviors (e.g., drug abstinence or medication adherence) to gain access to the workplace and maintain maximum pay. To assess skill levels upon entry into the workplace program, participants completed the Wide Range Achievement Test (WRAT-3 or WRAT-4; Wilkinson, 1993), a widely used instrument that assesses achievement in reading, spelling, and math. The present analysis presents results from the WRAT assessment for several drug-addicted groups that were enrolled in one of six different randomized controlled clinical trials evaluating the therapeutic workplace in the treatment of drug addiction. The trials were conducted between February 2001 and September 2009 and included homeless individuals with alcohol dependency, patients enrolled in methadone treatment who continued to use opiates and cocaine, and opioid-dependent injection drug users.

2. Method

2.1. Study participants and setting

The therapeutic workplace research was conducted in the Center for Learning and Health, a treatment-research unit located at the Johns Hopkins Bayview Medical Center (Baltimore, MD). The Center for Learning and Health is dedicated to addressing the interrelated problems of addiction, unemployment, and poverty. In all studies, participants were invited to attend the workplace where they could work and earn wages in vouchers exchangeable for goods and services.

Participants for the present analysis (N = 559) were enrolled in one of six clinical trials conducted at the Center for Learning and Health. The main results of the clinical trials have been presented elsewhere (DeFulio et al., 2012; Donlin, Knealing, Needham, Wong, & Silverman, 2008; Dunn et al., 2013; Everly et al., 2011; Knealing, Wong, Diemer, Hampton, & Silverman, 2006; Koffarnus et al., 2011). While the inclusion criteria varied across the six studies, all participants were at least 18 years old, met DSM-IV criteria for opiate, cocaine, or alcohol dependence or provided a drug positive urine, and were unemployed (i.e., reported no work in the past 30 days and earning <$200 in taxable income per month). Additional inclusion and exclusion criteria have been reported elsewhere (DeFulio et al., 2012; Donlin et al., 2008; Dunn et al., 2013; Everly et al., 2011; Knealing et al., 2006; Koffarnus et al., 2011).

2.2. Measures

2.2.1. Study and demographic characteristics

Demographic characteristics for participants in each of the studies were collected at intake using the Addiction Severity Index–Lite (ASI–Lite; McLellan et al., 1985). The ASI–Lite was used to evaluate drug use, educational, employment, family, medical, and legal histories. A summary of the demographic characteristics can be found in Table 1, along with characteristics of each study.

Table 1.

Study and participant characteristics

Characteristic Knealing et al. (2006) Donlin et al. (2008) Koffarnus et al. (2011) Everly et al. (2011) DeFulio et al. (2012) Dunn et al. (2013) All Studies
Study Characteristics
Years of enrollment 2001-2002 2003-2006 2001-2005 2006-2008 2008-2009 2006-2009
Population Cocaine dependent methadone patients Cocaine dependent methadone patients Homeless alcohol-dependent adults Opioid dependent adults Opioid dependent adults Opioid dependent injection drug users
Target of the intervention Opiate and cocaine abstinence Opiate and cocaine abstinence Alcohol abstinence Extended-release naltrexone adherence Extended-release naltrexone adherence Oral naltrexone adherence
Participant Characteristics Age, mean (SD) 37 (6) 43 (6) 43 (8) 42 (6) 42 (9) 43 (9) 42 (8)
Gender
    Female, % 89 78 19 45 43 41 49
Race
    Black, % 85 94 48 92 89 75 77
    White, % 15 6 50 8 11 22 22
    Other, % 0 0 2 0 0 3 1
Usually unemployed past 3 years, % 57 77 52 55 65 63 63
Duration of longest job, years, mean (SD) 4 (3) 6 (6) 6 (6) 4 (5) 4 (5) 4 (5) 5 (5)
Used in past 30 days, %
    Cocaine 100 100 45 80 73 96 82
    Heroin 72 57 23 100 100 100 71
    Alcohol 64 59 100 63 61 58 69
Open in a new tab

2.2.2. Wide range achievement test

Participants completed one of two parallel forms of the spelling, reading, and, in some cases, math subsections of the Wide Range Achievement Test (WRAT). Participants in the studies beginning before 2006 completed Version 3 of the WRAT whereas all other participants completed Version 4. In the spelling subsection, participants were asked to write single letters and words that were read aloud by the test administrator; items increased in difficulty as the test progressed. The test was discontinued after 10 consecutive spelling errors. In the reading subsection, participants were given cards with single letters or words. Participants were asked to read aloud the test items, beginning with the letters and progressing to increasingly more difficult words. This subset was discontinued after 10 consecutive reading errors. In the math subsection, participants were asked to complete written problems in addition, subtraction, multiplication, and division. Participants were given a maximum of 15 min to complete this portion of the test.

3. Results

Figure 1 provides a summary of the highest grade of education that participants completed. Approximately 60% of participants completed 12 or more years of education, indicating that a little over half of the participants had earned a high school diploma. About 34% of participants completed between nine to eleven years of education and a small percentage (6%) only completed eight or less years; about 40% of participants did not graduate from high school.

Fig. 1.

Fig. 1

Open in a new tab

The percentage of participants who completed 12 or more years of education (black bars), 9 to 11 years of education (striped bars), or 8 or less years of education (grey bars) across six different studies conducted at the Center for Learning and Health in Baltimore, MD.

Figure 2 shows participant's estimated grade levels in reading, spelling, and math across the different study populations. A large percentage of participants were at or below the seventh grade level in academic achievement in reading, spelling, and math (approximately 43% of participants in reading, 61% in spelling, and 81% in math), and about 23% of participants were at or below the fourth grade level in these areas. Table 2 shows WRAT classifications of academic achievement levels based on standard scores. The national mean for the standard scores is set at 100 and the standard deviation is set at 15, the same metric as IQ tests (Wilkinson, 1993). Approximately 64% of participants in reading, 70% in spelling, and 76% in math were classified as Low Average or below, and about 19%, 24%, and 13% of participants, respectively, were classified as Deficient in these areas. Almost no participants were classified as above average (High Average, Superior, or Very Superior).

Fig. 2.

Fig. 2

Open in a new tab

Wide Range Achievement Test (WRAT) reading (top panel), spelling, (middle panel), and math (bottom panel) levels across six different studies conducted at the Center for Learning and Health in Baltimore, MD. The filled circles show grade levels for individual participants and the grey, horizontal lines show group means.

Table 2.

Participants in each of the Wide Range Achievement Test (WRAT) classifications of academic achievement in reading, spelling, and math

WRAT classification Standard scorea (Range) Participants (%)
Reading (n = 528) Spelling (n = 528) Math (n = 233)
Very superior ≥130 0.0 0.0 0.0
Superior 120-129 0.0 0.0 0.4
High average 110-119 1.3 1.1 0.0
Average 90-109 34.3 29.2 23.2
Low average 80-89 25.8 25.4 33.9
Borderline 70-79 19.5 20.6 29.6
Deficient ≤69 19.1 23.7 12.9
Open in a new tab

Note. Data that were missing were excluded from the analysis.

a

Standard scores are based on age group norms.

Independent-samples t-tests were conducted comparing grade levels of academic achievement in reading, spelling, and math among participants who did and did not graduate from high school. Participants who graduated from high school compared to those who did not had significantly higher estimated grade levels in reading (M = 7.88 versus 5.95, respectively; p < 0.001), spelling (M = 7.21 versus 5.13, respectively; p < 001), and math (M = 6.60 versus 4.94, respectively; p < 0.001). While participants who graduated from high school had higher estimated grade levels across all three of the academic categories, mean grade equivalencies were still below the eighth grade level.

Spearman's correlation coefficients were calculated for educational and employment characteristics. The highest grade of education that participants completed was significantly correlated with the estimated grade levels in reading (P = 0.359, p < 0.001), spelling (P = 0.399, p < 0.001), and math (P = 0.386, p < 0.001). The highest grade of education completed was not significantly correlated with being usually unemployed in the past three years (P = −0.041, p = 0.341), but was significantly correlated with longest durations of full-time employment (P = 0.311, p < 0.001). Being usually unemployed in the past three years was not significantly correlated with estimated grade levels in reading (P = −0.044, p = 0.314), spelling (P = −0.041, p = 0.354), and math (P = 0.059, p = 0.373). Longest durations of full-time employment was not significantly correlated with estimated grade levels in reading (P = 0.067, p = 0.127) and spelling (P = 0.018, p = 0.675), but was significantly correlated with math (P = 0.138, p = 0.036).

4. Discussion

The present analysis provides information on the academic skills of chronically unemployed adults with histories of drug addiction collected between February 2001 and September 2009. The academic achievement tests indicated that most of the participants lacked basic skills in reading, spelling, and math. Even though a little more than half of the participants completed high school, the majority were at or below the seventh grade level of academic achievement. Furthermore, most participants had academic achievement levels that were below average compared to other persons in their age group and almost no participants had academic achievement levels that were above average (Table 2). Despite the fact that participants in this analysis were studied across several years and were from diverse populations, they showed remarkably similar rates of high school completion (Fig. 1) and academic skill levels (Table 2 and Fig. 2). The strong positive correlation between education and employment status (Psacharopoulos, 1994; Psacharopoulos & Patrinos, 2004) suggests that teaching basic skills may be necessary to improve long-term employment status, and the present study shows that the large majority of unemployed drug-addicted individuals lack basic academic skills. Our finding that attainment of a high school diploma is associated with increased academic skill aligns well with data from the general population (e.g., Kutner et al., 2007), but our results may be unique in that the level of academic skill among those with a diploma was still remarkably low, with mean grade equivalencies in reading, spelling, and math at about the seventh grade level. Although establishing basic skills does not directly address chronic unemployment or drug addiction, it may help individuals obtain the jobs they desire and function effectively in those jobs, and thus may play a key role in addiction recovery.

While the present study focused on academic skill levels, drug-addicted individuals in exiting treatment face many additional barriers to employment. These include limited work skills and experience; lack of job search and interviewing skills; and employers’ reluctance to hire persons with drug addiction and criminal histories (Atkinson, Lee, Dayton-Shotts, & French, 2001; Lidz, Sorrentino, Robinson, & Bunce, 2004; Meara, 2006; Sigurdsson, Ring, O'Reilly, & Silverman, 2012; Wong & Silverman, 2007; Zanis, Coviello, Alterman, & Appling, 2001). Any successful employment intervention will necessarily have to tackle the barriers to employment that a jobseeker encounters.

Despite the potential benefits of employment programs that incorporate basic-skills training, educational programs often fail to consistently engage participants. In a large-scale randomized controlled study that evaluated “education-focused” programs for adult welfare recipients (Hamilton et al., 2001), most participants did not attend the education and training programs long enough to reap their potential benefits (Bos et al., 2002). In the general population, few adults who do not have a high school diploma or equivalent participate in adult education. The U.S. Department of Education, National Center for Education Statistics (2007) estimated that among adults over the age of 16 who did not have a high school diploma or equivalent in 2005, only 1% participated in degree or diploma programs, and only 4% participated in work-related courses. These findings suggest that a critical component of any employment intervention will be procedures to reliably engage individuals and to establish targeted skills. Future research will have to determine if adult education that effectively retains participants in training and establishes academic and job skills can improve employment outcomes.

The strong association between unemployment and drug addiction suggests that employment interventions are an important and needed component of drug-addiction treatment. However, the application of employment interventions to drug-addicted individuals is likely to be challenging given the general difficulties with retention in intensive adult education training programs (Bos et al., 2002; Hamilton, 2002), and the low level of academic skill in this population as documented in the present paper. Effective retention strategies and instructional tools tailored to low-skilled adult learners will be required to overcome these challenges. Some prior research has shown that incentives can be effective in maintaining attendance in training (Koffarnus et al., 2011; Silverman, Chutuape, Bigelow, & Stitzer, 1996) and promoting progress in training programs (Koffarnus, DeFulio, Sigurdsson, & Silverman, 2013; Koffarnus, Wong et al., 2013). Key topics for future research include incentives and supports for the dual targets of retention and academic success, and evaluations of instructional design approaches and delivery mechanisms for adult basic education programs. Such work could prove useful or even essential in the development of large-scale programs designed to simultaneously address poverty, unemployment, and drug addiction.

Acknowledgments

The authors wish to thank Chris Burgess for his help with data analyses. This research was supported by grants R01DA13107, R01DA019497, R01AA12154, R01DA019386, and T32DA07209 from the National Institute on Drug Abuse.

Footnotes

Declarations of interest

The authors report no conflicts of interest. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute on Drug Abuse or the National Institutes of Health.

References

  1. Atkinson J, Lee D, Dayton-Shotts C, French C. Self-perceived job skills and employment barriers among non-drug using and chronic drug using welfare-to-work participants. Journal of Drug Issues. 2001;31:747–756. [Google Scholar]
  2. Bauman KJ, Ryan CL. What's It Worth? Field of Training and Economic Status. U.S. Census Bureau, U.S. Department of Commerce, Economic and Statistics; 2001. [June 2, 2012]. from http://www.census.gov/prod/2001pubs/p70-72.pdf. [Google Scholar]
  3. Bos JM, Scrivener S, Snipes J, Hamilton G. Improving basic skills: The effects of adult education in welfare-to-work programs. Manpower Demonstration Research Corporation; New York: 2002. (ERIC Document Reproduction Service No. ED464267) [Google Scholar]
  4. Day JC, Newburger EC. The big payoff: Educational attainment and synthetic estimates of work-life earnings. U.S. Census Bureau, U.S. Department of Commerce, Economic and Statistics; 2002. [June 2, 2012]. from http://www.census.gov/prod/2002pubs/p23-210.pdf. [Google Scholar]
  5. DeFulio A, Everly JJ, Leoutsakos JS, Umbricht A, Fingerhood M, Bigelow GE, Silverman K. Employment-based reinforcement of adherence to an FDA approved extended release formulation of naltrexone in opioid-dependent adults: A randomized controlled trial. Drug and Alcohol Dependence. 2012;120:48–54. doi: 10.1016/j.drugalcdep.2011.06.023. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Donlin WD, Knealing TW, Needham M, Wong CJ, Silverman K. Attendance rates in a workplace predict subsequent outcome of employment-based reinforcement of cocaine abstinence in methadone patients. Journal of Applied Behavior Analysis. 2008;41:499–516. doi: 10.1901/jaba.2008.41-499. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Dunn KE, Defulio A, Everly JJ, Donlin WD, Aklin WM, Nuzzo PA, Silverman K, et al. Employment-based reinforcement of adherence to oral naltrexone treatment in unemployed injection drug users. Experimental and Clinical Psychopharmacology. 2013;21:74. doi: 10.1037/a0030743. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Everly JJ, DeFulio A, Koffarnus MN, Leoutsakos JS, Donlin WD, Aklin WM, Silverman K, et al. Employment-based reinforcement of adherence to depot naltrexone in unemployed opioid-dependent adults: A randomized controlled trial. Addiction. 2011;106:1309–1318. doi: 10.1111/j.1360-0443.2011.03400.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Ginexi EM, Foss MA, Scott CK. Transitions from treatment to work: Employment patterns following publicly funded substance abuse treatment. Journal of Drug Issues. 2003;33:497–518. [Google Scholar]
  10. Hamilton G. Moving people from welfare to work: Lessons from the national evaluation of welfare-to-work strategies. Manpower Demonstration Research Corporation; New York: 2002. (ERIC Document Reproduction Service No. ED469794) [Google Scholar]
  11. Hamilton G, Freedman S, Gennetian L, Michalopoulos C, Walter J, Adams-Ciardullo D, Ricchetti B, et al. How effective are different welfare-to-work approaches? Five-year adult and child impacts for eleven programs. Manpower Demonstration Research Corporation; New York: 2001. (ERIC Document Reproduction Service No. ED469792) [Google Scholar]
  12. Higgins ST, Silverman K. Introduction. In: Higgins ST, Silverman K, Heil SH, editors. Contingency management in substance abuse treatment. Guilford; New York: 2008. pp. 1–15. [Google Scholar]
  13. Hubbard RL, Craddock SG, Anderson J. Overview of 5-year follow-up outcomes in the drug abuse treatment outcome studies (DATOS). Journal of Substance Abuse Treatment. 2003;25:125–134. doi: 10.1016/s0740-5472(03)00130-2. [DOI] [PubMed] [Google Scholar]
  14. Kidorf M, Stitzer ML, Brooner RK, Goldberg J. Contingent methadone take-home doses reinforce adjunct therapy attendance of methadone maintenance patients. Drug and Alcohol Dependence. 1994;36:221–226. doi: 10.1016/0376-8716(94)90148-1. [DOI] [PubMed] [Google Scholar]
  15. Knealing TW, Wong CJ, Diemer KN, Hampton J, Silverman K. A randomized controlled trial of the therapeutic workplace for community methadone patients: A partial failure to engage. Experimental and Clinical Psychopharmacology. 2006;14:350. doi: 10.1037/1064-1297.14.3.350. [DOI] [PubMed] [Google Scholar]
  16. Koffarnus MN, DeFulio A, Sigurdsson SO, Silverman K. Performance pay improves engagement, progress, and satisfaction in computer-based job skills training of low-income adults. Journal of Applied Behavior Analysis. 2013;46:395–406. doi: 10.1002/jaba.51. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Koffarnus MN, Wong CJ, Diemer K, Needham M, Hampton J, Fingerhood M, Silverman K, et al. A randomized clinical trial of a therapeutic workplace for chronically unemployed, homeless, alcohol-dependent adults. Alcohol and Alcoholism. 2011;46:561–569. doi: 10.1093/alcalc/agr057. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Koffarnus MN, Wong CJ, Fingerhood M, Svikis DS, Bigelow GE, Silverman K. Monetary incentives to reinforce engagement and achievement in a job skills training program for homeless, unemployed adults. Journal of Applied Behavior Analysis. 2013;46:582–591. doi: 10.1002/jaba.60. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Kutner M, Greenberg E, Jin Y, Boyle B, Hsu YC, Dunleavy E. Literacy in Everyday Life: Results from the 2003 National Assessment of Adult Literacy. NCES 2007-490. National Center for Education Statistics. 2007 [Google Scholar]
  20. Lidz V, Sorrentino DM, Robison L, Bunce S. Learning from disappointing outcomes: An evaluation of prevocational interventions for methadone maintenance patients. Substance Use and Misuse. 2004;39:2287–2308. doi: 10.1081/ja-200034631. [DOI] [PubMed] [Google Scholar]
  21. Magura S. The role of work in substance dependency treatment: A preliminary overview. Substance Use and Misuse. 2003;38:1865–1876. doi: 10.1081/ja-120024244. [DOI] [PubMed] [Google Scholar]
  22. Magura S, Staines GL, Blankertz L, Madison EM. The effectiveness of vocational services for substance users in treatment. Substance Use & Misuse. 2004;39(13-14):2165–2213. doi: 10.1081/ja-200034589. [DOI] [PubMed] [Google Scholar]
  23. McLellan AT, Luborsky L, Cacciola J, Griffith J, Evans F, Barr HL, O'Brien CP. New data from the addiction severity index reliability and validity in three centers. The Journal of Nervous and Mental Disease. 1985;173:412–423. doi: 10.1097/00005053-198507000-00005. [DOI] [PubMed] [Google Scholar]
  24. Meara E. Welfare reform, employment, and drug and alcohol use among low-income women. Harvard Review of Psychiatry. 2006;14:223–232. doi: 10.1080/10673220600883150. [DOI] [PubMed] [Google Scholar]
  25. Psacharopoulos G. Returns to investment in education: A global update. World Development. 1994;22:1325–1343. [Google Scholar]
  26. Psacharopoulos G, Patrinos HA. Returns to investment in education: A further update. Education and Economics. 2004;12:111–134. [Google Scholar]
  27. Platt JJ. Vocational rehabilitation of drug abusers. Psychological Bulletin. 1995;117:416. doi: 10.1037/0033-2909.117.3.416. [DOI] [PubMed] [Google Scholar]
  28. Schildhaus S, Gerstein D, Brittingham A, Cerbone F, Dugoni B. Services research outcomes study: Overview of drug treatment population and outcomes. Substance Use and Misuse. 2000;35:1849–1877. doi: 10.3109/10826080009148243. [DOI] [PubMed] [Google Scholar]
  29. Sigurdsson SO, Ring BM, O'Reilly K, Silverman K. Barriers to employment among unemployed drug users: Age predicts severity. The American Journal of Drug and Alcohol Abuse. 2012;38:580–587. doi: 10.3109/00952990.2011.643976. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Silverman K, Chutuape MAD, Svikis DS, Bigelow GE, Stitzer ML. Incongruity between occupational interests and academic skills in drug abusing women. Drug and Alcohol Dependence. 1995;40:115–123. doi: 10.1016/0376-8716(95)01196-x. [DOI] [PubMed] [Google Scholar]
  31. Silverman K, Chutuape MAD, Bigelow GE, Stitzer ML. Voucher-based reinforcement of attendance by unemployed methadone patients in a job skills training program. Drug and Alcohol Dependence. 1996;41:197–207. doi: 10.1016/0376-8716(96)01252-5. [DOI] [PubMed] [Google Scholar]
  32. Sterling RC, Gottheil E, Glassman SD, Weinstein SP, Serota RD, Lundy A. Correlates of employment: A cohort study. The American Journal of Drug and Alcohol Abuse. 2001;27:137–146. doi: 10.1081/ada-100103123. [DOI] [PubMed] [Google Scholar]
  33. Svikis DS, Keyser-Marcus L, Stitzer M, Rieckmann T, Safford L, Loeb P, Zweben J, et al. Randomized multi-site trial of the Job Seekers’ Workshop in patients with substance use disorders. Drug and alcohol dependence. 2012;120:55–64. doi: 10.1016/j.drugalcdep.2011.06.024. [DOI] [PMC free article] [PubMed] [Google Scholar]
  34. U.S. Department of Education, National Center for Education Statistics . The Condition of Education 2007 (NCES 2007-064) U.S. Government Printing Office; Washington, DC: 2007. [June 7, 2012]. from http://nces.ed.gov/pubs2007/2007064.pdf. [Google Scholar]
  35. Wilkinson G. The wide range achievement test (WRAT-3): Administration manual. wide range; Wilmington, DE: 1993. [Google Scholar]
  36. Wong CJ, Silverman K. Establishing and maintaining job skills and professional behaviors in chronically unemployed drug abusers. Substance Use and Misuse. 2007;42:1127–1140. doi: 10.1080/10826080701407952. [DOI] [PubMed] [Google Scholar]
  37. Zanis DA, Coviello D, Alterman AI, Appling SE. A community-based trial of vocational problem-solving to increase employment among methadone patients. Journal of Substance Abuse Treatment. 2001;21:19–26. doi: 10.1016/s0740-5472(01)00177-5. [DOI] [PubMed] [Google Scholar]

RESOURCES