Two-Year Outcomes of Treatment for Methamphetamine Use

Sex-Dependent Alterations in the mRNA Expression of Enzymes Involved in Dopamine Synthesis and Breakdown After Methamphetamine Self-Administration

Sex differences have been reported in methamphetamine (METH) use disorder in humans and in animal models of METH exposure. Specifically, animals that self-administer METH show sex-related dissimilarities in dopamine (DA) metabolism. To better understand the molecular bases for the differences in DA metabolism, we measured the levels of mRNAs of enzymes that catalyze DA synthesis and breakdown in the prefrontal cortex (PFC), nucleus accumbens (NAc), dorsal striatum (dSTR), and hippocampus (HIP) of rats that had self-administered METH. There were significant sex differences in control rats, with males having higher basal levels of Th in the PFC and dSTR, Ddc in the NAc, and MaoB in the HIP. In contrast, female controls showed higher basal levels of Comt in the HIP. Male and female METH SA rats also showed some distinct responses to the drug. Specifically, female METH rats exhibited increased expression of Ddc and MaoB, whereas male METH animals showed higher levels of Comt mRNA in the PFC compared to their respective controls. In the NAc, male METH rats displayed decreased Th and Ddc mRNA levels. Together, our results identified sex-dependent and region-specific changes in the mRNA expression of several enzymes involved in DA synthesis and breakdown in response to METH SA, with the majority of differences being observed in the mesocorticolimbic dopaminergic system. These findings are of significant translational importance providing further support for the inclusion of sex as an important variable when planning and evaluating therapeutic interventions against METH use disorder in human clinical studies.

Sex differences in methamphetamine use disorder perused from pre-clinical and clinical studies: Potential therapeutic impacts

Methamphetamine (METH) use, and misuse are associated with severe socioeconomic consequences. METH users develop tolerance, lose control over drug taking behaviors, and suffer frequent relapses even during treatment. The clinical course of METH use disorder is influenced by multifactorial METH-induced effects on the central and peripheral nervous systems. Although these METH-induced consequences are observed in humans of all ages, races, and sexes, sexual dimorphism in these outcomes have been observed in both pre-clinical and clinical settings. In this review, we have provided a detailed presentation of the sex differences reported in human and animal studies. We have therefore presented data that identified the influences of sex on METH pharmacokinetics, METH-induced changes in behaviors, cognitive processes, structural changes in the brain, and the effects of the drug on neurotransmitter systems and molecular mechanisms. Finally, we highlighted the potential significance of sex as a critical variable that should be considered when planning the development of new pharmacotherapeutic approaches against MEH use disorder in humans.

Characterising the increasing prevalence of crystal methamphetamine use in Vancouver, Canada, from 2006-2017: A gender-based analysis

INTRODUCTION

Methamphetamine use is increasing in North America and is associated with numerous negative health effects and social harms. As drug-related harms are often gendered, this study sought to examine the differential impacts of gender on the trends, risk factors and health implications of crystal methamphetamine use among a Canadian cohort of people with high rates of injection polysubstance use.

METHODS

Data were collected from two prospective cohorts of people who inject drugs in Vancouver, Canada. We examined trends in reported crystal methamphetamine use from 2006-2017 using the Cochrane-Armitage test for trend. We used multivariable generalised estimating equations, stratified by gender, to determine independent risk factors and health outcomes associated with crystal methamphetamine use.

RESULTS

In total, 1984 participants were included in the study, including 694 (35%) women. The prevalence of reported crystal methamphetamine use within the previous 6 months rose from 19% in 2006 to 36% in 2017, with a rise seen in both genders (P < 0.001). Reported crystal methamphetamine use was associated with numerous risk behaviours and drug-related harms in both genders, and in women it was associated with an increase in experiences of sexual violence (adjusted odds ratio 1.64, 95% confidence interval 1.18, 2.27).

CONCLUSIONS

These findings demonstrate the rising prevalence of reported crystal methamphetamine use in Vancouver in a cohort with high rates of polysubstance use. This work highlights drug and sex-related risk behaviours associated with crystal methamphetamine use for both genders, and underscores the need to develop strategies to address the growing use of crystal methamphetamine.

Improving Rehabilitative Care of Methamphetamine Users in Germany: The Expert's Perspective

Methamphetamine is one of the most frequently used drugs worldwide. In Germany, methamphetamine use has greatly increased in recent years, presenting the rehabilitative treatment system with new challenges. In this study, we identified deficits and possibilities for optimization in the field of medical rehabilitation. A total of 39 interviews and two focus groups with experts along the treatment course of methamphetamine users were conducted. Our analyses indicate that methamphetamine users are more difficult to treat compared with patients who consume other drugs. They are more likely to be associated with problematic characteristics and behaviors than other rehabilitants. Several health care deficits were revealed: too short rehabilitation treatment, no specific or differentiated therapy concepts, lack of capacity for education and vocational training, lack of outpatient options, and insufficient facilities for parents and children. Findings indicate that inadequate rehabilitation is being provided for methamphetamine users in Germany, indicating a need to adapt treatment for this group.

History of Alcohol and Opioid Use Impacts on the Long-Term Recovery Trajectories of Methamphetamine-Dependent Patients

Methamphetamine (MA) has become one of the most widely used illicit substances in China and the rest of the world as well. Relapse, incarceration or death was observed after compulsory rehabilitation. However, the knowledge of recovery patterns among MA-dependent patients, early or late occurrence of these negative consequences, is limited. The aims were to explore the long-term recovery patterns and associated factors among MA-dependent patients in Shanghai, China. MA-dependent patients discharged from Shanghai compulsory rehabilitation facilities in 2009-2012 were recruited in a baseline survey. The baseline data of 232 patients were then linked with their long-term follow-up data from official records. Group-based trajectory modeling was applied to identify distinctive trajectories of the occurrence of negative consequences (incarceration, or readmission to compulsory rehabilitation, or death). Patients with monthly status data were found recovering with three distinctive trajectories: rare, late, and early occurrence groups. Multinomial logistic regression showed that having alcohol use history was associated with an increased likelihood of being in the late occurrence group relative to the rare occurrence group. Having opioid use history was associated with an increased likelihood of being in the early occurrence group relative to the rare occurrence group. In addition, being female was associated with decreased likelihood of being in the late occurrence group relative to the rare occurrence group.

Sex as a biological variable: Drug use and abuse

The study of sex as a biological variable is a necessary emphasis across a wide array of endpoints, including basic neuroscience, medicine, mental health, physiology and behavior. The present review summarizes work from clinical and preclinical populations on sex differences in drug use and abuse, ranging from initiation to escalation/dysregulation and from drug cessation/abstinence to relapse. These differences are analyzed in the context of the addiction cycle conceptualization of Koob and his colleagues and address patterns of drug use (binge/intoxication), motivation underlying its use (withdrawal/negative affect) and likelihood and causes of craving and relapse of drug taking (preoccupation/anticipation). Following this overview, an assessment of the basis for the reported sex differences is discussed in the context of the affective (rewarding and aversive) properties of drugs of abuse and how such properties and their balance vary with sex and contribute to drug intake. Finally, the interaction of sex with several experiential (drug history) and subject (age) factors and how these interactions affect reward and aversion are discussed to highlight the importance of understanding such interactions in predicting drug use and abuse. We note that sex as a biological variable remains one of critical evaluation and that such investigations of sex differences in drug use and abuse continue and be expanded to assess all facets of their mediation, including these affective properties, how their balance may be impacted by the multiple conditions under which drugs are taken and how this overall balance affects drug use and addiction vulnerability.

Mental distress following inpatient substance use treatment, modified by substance use; comparing voluntary and compulsory admissions

Background

Treatment services to patients with substance use disorders (SUDs), including those mandated to treatment, needs to be evaluated and evidence based. The Norwegian Municipal Health Care Act (NMHCA) calls for compulsory treatment for persons with “severe and life-threatening substance use disorder” if these individuals are not otherwise willing to be voluntarily treated and consequently risk their lives over drug use. Mental distress is known to be high among SUD patients admitted to inpatient treatment. The purpose of this study is to describe changes in mental distress from admission to a 6-month follow-up in patients with SUDs, which underwent either voluntary or compulsory treatment.

Method

This prospective study followed 202 hospitalized patients with SUDs who were admitted voluntarily (VA; n = 137) or compulsorily (CA; n = 65). Levels of mental distress were assessed with SCL-90-R. Of 123 patients followed-up at 6 months, 97 (62 VA and 35 CA) had rated their mental distress at admission, discharge and follow-up. Sociodemographics and substance use severity were recorded with the use of The European Addiction Severity Index (EuropASI). We performed a regression analysis to examine factors associated with changes in psychiatric distress at the 6-month follow-up.

Results

The VA group exhibited higher mental distress than the CA group at admission, but both groups improved significantly during treatment. At the 6-month follow-up, the VA group continued to show reduced distress, but the CA group showed increases in mental distress to the levels observed before treatment. The deterioration appeared to be associated with higher scores that reflected paranoid ideas, somatization, obsessive-compulsive symptoms, interpersonal sensitivity, and depression. Active substance use during follow-up was significantly associated with increased mental distress.

Conclusion

In-patient treatment reduces mental distress for both CA and VA patients. The time after discharge seems critical especially for CA patients regarding active substance use and severe mental distress. A greater focus on continuing care initiatives to assist the CA patients after discharge is needed to maintain the reduction in mental distress during treatment. Continuing-care initiatives after discharge should be intensified to assist patients in maintaining the reduced mental distress achieved with treatment.

Trial registration

ClinicalTrials.gov NCT 00970372 December 02, 2016.

Predictors of time to relapse in amphetamine-type substance users in the matrix treatment program in Iran: a Cox proportional hazard model application

BACKGROUND

The aim of this study was to determine which predictors influence the risk of relapse among a cohort of amphetamine-type substance (ATS) users in Iran.

METHODS

A Cox proportional hazards model was conducted to determine factors associated with the relapse time in the Matrix treatment program provided by the Iranian National Center of Addiction Studies (INCAS) between March 2010 and October 2011.

RESULTS

Participating in more treatment sessions was associated with a lower probability of relapse. On the other hand, patients with less family support, longer dependence on ATS, and those with an experience of casual sex and a history of criminal offenses were more likely to relapse.

CONCLUSION

This study broadens our understanding of factors influencing the risk of relapse in ATS use among an Iranian sample. The findings can guide practitioners during the treatment program.

Transcriptional and epigenetic substrates of methamphetamine addiction and withdrawal: evidence from a long-access self-administration model in the rat

Methamphetamine use disorder is a chronic neuropsychiatric disorder characterized by recurrent binge episodes, intervals of abstinence, and relapses to drug use. Humans addicted to methamphetamine experience various degrees of cognitive deficits and other neurological abnormalities that complicate their activities of daily living and their participation in treatment programs. Importantly, models of methamphetamine addiction in rodents have shown that animals will readily learn to give themselves methamphetamine. Rats also accelerate their intake over time. Microarray studies have also shown that methamphetamine taking is associated with major transcriptional changes in the striatum measured within a short or longer time after cessation of drug taking. After a 2-h withdrawal time, there was increased expression of genes that participate in transcription regulation. These included cyclic AMP response element binding (CREB), ETS domain-containing protein (ELK1), and members of the FOS family of transcription factors. Other genes of interest include brain-derived neurotrophic factor (BDNF), tyrosine kinase receptor, type 2 (TrkB), and synaptophysin. Methamphetamine-induced transcription was found to be regulated via phosphorylated CREB-dependent events. After a 30-day withdrawal from methamphetamine self-administration, however, there was mostly decreased expression of transcription factors including junD. There was also downregulation of genes whose protein products are constituents of chromatin-remodeling complexes. Altogether, these genome-wide results show that methamphetamine abuse might be associated with altered regulation of a diversity of gene networks that impact cellular and synaptic functions. These transcriptional changes might serve as triggers for the neuropsychiatric presentations of humans who abuse this drug. Better understanding of the way that gene products interact to cause methamphetamine addiction will help to develop better pharmacological treatment of methamphetamine addicts.

Time to relapse following treatment for methamphetamine use: a long-term perspective on patterns and predictors

INTRODUCTION

This paper describes methamphetamine (MA) use patterns, specifically the duration of continuing abstinence ("time to relapse") for periods averaging 5 years post-discharge from treatment for MA use, and the relationship with selected user and treatment characteristics.

METHODS

A sample of 350 treatment admissions from a large county substance use disorder (SUD) treatment system was randomly selected (within gender, race/ethnicity, treatment modality strata). Retrospective self-report data are from natural history interviews (NHI) conducted approximately 3 years after treatment and a follow-up of 2-3 years later. Relapse is defined as any use of MA with time as the number of months of continuous MA abstinence after treatment discharge until relapse. This outcome was constructed from a monthly MA use timeline using NHI data. A Cox model was used to examine time to relapse and predictors.

RESULTS

Sixty-one percent of the sample relapsed to MA use within 1 year after treatment discharge and 14% during years 2-5. Significant protective factors predicting longer time to relapse included having experienced serious MA-related psychiatric/behavioral problems (hazard ratio [HR]=0.75, p=0.027), longer duration of the index treatment episode (HR=0.93, p=0.001), and participating in self-help or other treatment during the post-treatment abstinence period (HR=0.29, p<0.001); risk factors for shorter time to relapse included having a parent with alcohol and/or drug use problems (HR=1.35, p=0.020) and involvement in MA sales (HR=1.48, p=0.002).

CONCLUSIONS

Results contribute a long-term perspective on patterns of MA use following treatment and support a need for early post-treatment and long-term continuing care and relapse-prevention services.

Pregnancy and fetal loss reported by methamphetamine-using women

To better understand substance use disorder treatment needs of pregnant and parenting women who use methamphetamine (MA), this paper describes pregnancy histories and fetal losses for women who were treated for MA use (N = 153) with reference to a national sample, and describes their drug use, sexual risk behaviors, and mental health status. MA users reported an average of 4.6 total pregnancies and 2.1 fetal losses, whereas women in a general population survey reported 3.2 and 1.2, respectively. Higher numbers of pregnancies and fetal losses were correlated with specific substance abuse and mental health problems including early sexual abuse and cognitive problems. The combination of MA users' especially high numbers of pregnancies, fetal losses, and rates of risk behaviors suggest high social and health care costs for this population. Prenatal care may provide a vector through which women can be connected to risk reduction interventions and gender-responsive treatment services addressing substance use and mental health needs.

Pharmacotherapy of amphetamine-type stimulant dependence: an update

ISSUES

Methamphetamine- or amphetamine-type stimulants are the second most frequently used illicit drug worldwide, second only to cannabis. Behavioural treatments are efficacious, but their impact is limited underscoring the need for other treatment options, notably, pharmacotherapy.

APPROACH

A review of randomised controlled trials of pharmacotherapies for methamphetamine- or amphetamine-type stimulants was performed using PubMed and Google Scholar databases. Evidence for efficacy of medications is reported.

KEY FINDINGS

Clinical trials have yielded no broadly effective pharmacotherapy. Promising signals have been observed for methylphenidate, naltrexone, bupropion and mirtazapine in subgroups of patients in reducing stimulant use (e.g. patients with less severe dependence at baseline and men who have sex with men), though none has produced an unambiguous, replicable signal of efficacy.

IMPLICATIONS

Problems in Phase II trials, including high dropout rates, missing data and a lack of agreement on outcomes, complicate efforts to find a broadly effective pharmacotherapy for amphetamine-type stimulant disorders. Efforts to address these problems include calls for better validation of pharmacological target exposure, receptor binding and functional modulation. As well, there is a need for agreement in using findings from preclinical and early phases of the medication development process for selecting better pharmacotherapy candidates.

CONCLUSION

After over 20 years of efforts worldwide to develop a broadly effective medication for dependence on methamphetamine- or amphetamine-type stimulants, no candidate has emerged. This highlights the need for new compounds, consistent and stringent research methods, better integration between preclinical and clinical stages of medication development, and improved collaboration between government, industry and researchers.

Patterns of treatment utilization and methamphetamine use during first 10 years after methamphetamine initiation

The study examined joint trajectories of methamphetamine (MA) use and substance abuse treatment utilization and identified differences among pattern groups for a sample of 348 treated for MA use. Results from group-based trajectory modeling showed that treatment utilization during the first 10 years after initiation of MA use could be categorized into three distinctive patterns: about half the MA users have a pattern of low treatment utilization; one-fourth follow a quicker-to-treatment trajectory with higher probability of treatment during the first 5 years of MA use and less treatment in the next 5 years; and one-fourth have a slower-to-treatment trajectory with more treatment during the second half of the 10-year period. Four MA use patterns were identified: consistently low use, moderate, and high use, as well as a decreasing use pattern. Periods of greater likelihood of treatment participation were associated with periods of decreasing or lower frequency of MA use.

Treatment outcomes for methamphetamine users: California Proposition 36 and comparison clients

Methamphetamine (meth) is a major drug of abuse in California and several other states, particularly among criminal offender populations. Over the past decade, substance abuse treatment systems have had to adapt to and accommodate the increasing needs of meth users and, in California, deal with the impact of Proposition 36, which has resulted in a greater number of criminal offenders entering the treatment system. This study examines selected treatment performance and outcome indicators for California Proposition 36 offenders entering substance abuse treatment for meth use and compares their performance and outcomes to other subgroups of California treatment clients differentiated by whether or not they were admitted to treatment through Proposition 36 and whether or not their primary substance was meth. Significant improvements in all outcome domains were seen across the populations, and treatment performance and outcomes were not substantively inferior for the offender or meth-using groups.

An examination of drug craving over time in abstinent methamphetamine users

Craving for addictive drugs may predict relapse in abstinent addicts. To assess relationships between craving and use, we examined changes in craving for methamphetamine (MA) in a sample of 865 outpatients in a multisite 16-week MA-treatment study. Craving was assessed on a 0-100 scale, and MA use was assessed by self-report and confirmed by urinalysis. We hypothesized that the magnitude of craving would decline (decay) with increased time of abstinence, and that decay would be greater for more frequent MA users, and greater for intravenous (IV) users and smokers as compared to those who used MA intranasally. Craving declined significantly as the number of weeks of consecutive abstinence increased. Rate of decay was greater for IV users and smokers as compared to both intranasal users and oral users, but not for more frequent users of MA. Rate of decay was independent of age, gender, and race/ethnicity. The trajectory to 0 (no) craving was 1 week shorter for females than males because females had significantly lower pretreatment craving scores compared to males. This study confirms that the sooner MA-dependent people are able to quit using and the longer that they are able to stay abstinent, the more likely it is that their craving for MA will decrease over time. 

Predicting adherence to treatment for methamphetamine dependence from neuropsychological and drug use variables

Although some individuals who abuse methamphetamine have considerable cognitive deficits, no prior studies have examined whether neurocognitive functioning is associated with outcome of treatment for methamphetamine dependence. In an outpatient clinical trial of bupropion combined with cognitive behavioral therapy and contingency management (Shoptaw, S., Heinzerling, K.G., Rotheram-Fuller, E., Steward, T., Wang, J., Swanson, A.N., De La Garza, R., Newton, T., Ling, W., 2008. Randomized, placebo-controlled trial of bupropion for the treatment of methamphetamine dependence. Drug Alcohol Depend 96, 222-232.), 60 methamphetamine-dependent adults completed three tests of reaction time and working memory at baseline. Other variables that were collected at baseline included measures of drug use, mood/psychiatric functioning, employment, social context, legal status, and medical status. We evaluated the relative predictive value of all baseline measures for treatment outcome using Classification and Regression Trees (CART; Breiman, L., Friedman, J.H., Olshen, R.A., Stone, C.J., 1984. Classification and Regression Trees. Wadsworth, Belmont, CA.), a nonparametric statistical technique that produces easily interpretable decision rules for classifying subjects that are particularly useful in clinical settings. Outcome measures were whether or not a participant completed the trial and whether or not most urine tests showed abstinence from methamphetamine abuse. Urine-verified methamphetamine abuse at the beginning of the study was the strongest predictor of treatment outcome; two psychosocial measures (e.g., nicotine dependence and Global Assessment of Functioning) also offered some predictive value. A few reaction time and working memory variables were related to treatment outcome, but these cognitive measures did not significantly aid prediction after adjusting for methamphetamine usage at the beginning of the study. On the basis of these findings, we recommend that research groups seeking to identify new predictors of treatment outcome compare the predictors to methamphetamine usage variables to assure that unique predictive power is attained.

Correlates of stimulant treatment outcome across treatment modalities

OBJECTIVE

This study evaluated variables associated with stimulant use outcomes in stimulant users (N = 800) receiving care in community outpatient psychosocial or methadone maintenance treatment clinics as part of a national multi-site clinical trial.

METHODS

Results from the full sample were examined first, and then predictors were examined separately in the two treatment modalities.

RESULTS

A cocaine-positive urine sample at study intake was the most robust and consistent correlate of stimulant use outcome in all analyses. Psychiatric distress, social environment and employment had differential effects on outcome across modalities.

CONCLUSIONS/SIGNIFICANCE

This study confirms that intake assessments have considerable value in identifying problems to be addressed in treatment.

Profiles associated with treatment retention in Japanese patients with methamphetamine use disorder: preliminary survey

AIMS

To identify profiles associated with treatment retention in Japanese patients with methamphetamine use disorder.

METHODS

The study used a retrospective design based on clinical records. The subjects were 101 patients at the Kanagawa Psychiatric Center, Serigaya Hospital, who were diagnosed as having methamphetamine use disorder. They were divided in two groups, namely those who remained in treatment 3 months after the initial assessment, and those who did not. The primary analysis compared patient profiles between the two groups to detect discriminating variables, which were then submitted for secondary analysis using logistic regression to determine the most relevant predictor of retention.

RESULTS

Primary analysis indicated that older age, having psychotic symptoms, receiving public assistance, and history of incarceration were associated with treatment retention after 3 months. Secondary analysis showed that positive history of incarceration was the most significant predictor of the outcome.

CONCLUSIONS

History of incarceration had the most significant treatment-retention effect on Japanese patients with methamphetamine use disorder. The development and introduction of integrated programs that link methamphetamine-dependent offenders to drug treatment is recommended in outpatient treatment for Japanese patients with methamphetamine user disorder.

Gender differences in methamphetamine use and responses: a review

BACKGROUND

Men and women differ markedly with regard to their use of, and responses to, methamphetamine (MA) and related amphetamines. However, these gender differences oftentimes are given only a cursory consideration in the analyses of these MA effects.

OBJECTIVE

In this brief review, we summarize the data on gender differences in various parameters of MA use and responses. Such information on the pattern of male versus female differences in the use and responses to this psychostimulant can aid in tailoring gender-dependent treatment strategies.

METHODS

English-language articles were identified from MEDLINE as well as from reference lists of identified articles for the years 1966 to 2007. Search terms included various combinations of men/male, women/female, methamphetamine, and gender/sex differences. Only studies with human subjects were reviewed.

RESULTS

Women tend to begin MA use at earlier ages, appear more dependent on MA, but also respond better to treatment than do men. MA use appears to be associated with depression in women, and women seem more committed to MA, whereas men are more likely to use other drugs in the absence of access to MA. Female MA abusers had both larger volumes within the corpus callosum and more hyperperfused regions in the parietal and occipital areas of the brain, along with more genetic alterations but less MA-induced toxicity. Amphetamine-stimulated dopamine release was greater in men.

CONCLUSIONS

When considered in total, women seem more dependent on and committed to MA but show diminished (amphetamine-stimulated) dopamine responses and a decreased degree of toxicity, as indicated by a lower incidence of emergency department-related deaths involving MA. A pervasive comorbidity of depression or depression-related characteristics were present in women MA users, suggesting that MA may serve as a type of self-medication for their depression. These findings not only highlight the need for consideration of gender when assessing MA use, but also can serve to direct efforts at prevention and treatment programs that address the specific needs of men and women.

Criminal justice itreatment admissions for methamphetamine use in California: a focus on Proposition 36

Methamphetamine (MA) use is considered as one of the nation's most pressing drug problems. In California, MA use has outstripped all other drugs in epidemiological extent, law enforcement activities, and treatment services demand. An opportunity for further study of MA use and its treatment emerged from a change in offender sentencing options introduced by California's Substance Abuse and Crime Prevention Act of 2000 (SACPA). Results indicate that statewide admissions for MA rose from 8.4% in FY 1992/1993 to 34.6% in FY 2004/2005, a four-fold increase over the 13 years. From the year before SACPA implementation to the year after, the percentage of treatment admissions due to MA use increased from 18.8% to 25.6%, an increase largely due to the fact that SACPA admissions were over 50% MA users. With the exception of alcohol, MA users entering treatment through SACPA had higher completion rates (about one third) from community based treatment than users of other primary drugs. This result held true for demographic and other subgroups of MA users. Multivariate regression results illuminate the relative importance of the variables examined. Implication of the findings for policy, intervention services, and research are discussed.

Methamphetamine treatment: trends and predictors of retention and completion in a large state treatment system (1992-2002)

This report describes trends in treatment admissions for methamphetamine/amphetamine (MA) abuse from 1992 to 2002 in California and assesses predictors of treatment retention and completion. Results show such admissions increasing fivefold and representing a growing proportion of overall treatment admissions. Patients admitted for MA abuse were increasingly diverse in race/ethnicity, older in age, and more frequently under legal supervision status over time. There was a decrease in injection drug use. Several user characteristics played consistent roles as risk factors for noncompletion and shorter treatment retention for both residential and outpatient admissions: having lower than a high school education, being younger at treatment admission, having a disability, having greater severity of MA use, and using injection drugs. Consistently, those with legal supervision status at admission had higher completion rates and longer retention than those reporting no legal status. Overall, findings suggested that clients with greater socioeconomic disadvantage and more severe problems may require greater efforts (e.g., services) to be retained in treatment.