Treatment outcome, cognitive function, and psychopathology in methamphetamine users compared to other substance users.

BACKGROUND: The rising number of people using methamphetamine leads to an increasing need for treatment options for this patient group. Evidence-based research on the efficacy of treatment programs for methamphetamine users is limited. Due to specific characteristics of methamphetamine users, the question arises whether established treatment methods for individuals using other substances can be effective for the treatment of methamphetamine dependence as well. We hypothesize that there are significant differences between the two groups that may affect the effectiveness of treatment and worsen the prognosis of treatment outcomes for methamphetamine users compared to consumers of other substances. AIM: To investigate potential differences in cognitive functioning and psychopathology between methamphetamine users and other substance users and possible correlations with treatment outcomes. METHODS: A total of 110 subjects were recruited for an observational, longitudinal study from a German inpatient addiction treatment center: 55 patients with methamphetamine dependence and 55 patients with dependence of other substances ("OS group"). Both groups were examined at beginning (baseline) and end of treatment (after 6 mo) with regard to treatment retention, craving, cognitive functioning, psychosocial resources, personality traits, depression, and other psychiatric symptoms. Instruments used were Raven's IQ test, Mannheimer craving scale, cognitrone cognitive test battery, NEO personality factors inventory, Hamilton depression scale, Becks depression inventory, and a symptom checklist. The statistical methods used were χ 2-test, t-test and multiple mixed ANOVAs. RESULTS: A total drop-out rate of 40% (methamphetamine-group: 36.4%; OS-group: 43.6%) was observed without significant differences between groups. At baseline, methamphetamine-group subjects significantly differed from OS-group individuals in terms of a lower intelligence quotient, fewer years of education, slower working speed, and decreased working accuracy, as well as less cannabinoid and cocaine use. Methamphetamine-group subjects further showed a significantly lower score of conscientiousness, depressive, and psychiatric symptoms than subjects from the OS-group. In both groups, a reduction of craving and depressive symptoms and an improvement of working speed and working accuracy was noted after treatment. CONCLUSION: There are differences between methamphetamine users and users of other drugs, but not with regard to the effectiveness of treatment in this inpatient setting. There are differences in cognitive function and psychopathology between methamphetamine and other drugs users. The existing treatment options seem to be an effective approach in treating methamphetamine dependence.

Inhalant Abuse of Ethyl Chloride Spray: A Case Report.

Ethyl chloride spray, which is usually used to relieve pain after injuries, is increasingly being used as a sniffing alternative. The number of people using this is rising due to its easy availability, cost-effectiveness and legality. The high lipid solubility of ethyl chloride leads to a rapid absorption of it in the lungs. However, data on the biotransformation of ethyl chloride in humans are sparse. We present the case of a 53-year-old male who had been inhaling ethyl chloride up to 3 times a week since 25 years, and describe his symptoms and the circumstances of abuse. This should help raise awareness of this issue so that abuse can be recognized early and rapid action taken.

Just "Like Coffee" or Neuroenhancement by Stimulants?

Introduction: Pharmacological neuroenhancement (PN) is a topic of increasing importance and prevalence among students. However, there is a lack of differentiating PN substances, according to their psychoactive effects. In particular, there is a lack of data about PN by caffeinated drinks, even if coffee is a common and broadly used Neuroenhancer because of its cognitively enhancing effects regarding wakefulness, alertness and concentration. Materials and Methods: A web-survey was developed for German students and alumni about the non-medical use of caffeine for PN contained questions about coffee, caffeinated drinks and energy drinks, caffeine pills and methylxanthine tea regarding frequency and further contextual factors. Results: Six hundred and eighty-three participants completed the survey. Nearly all participants knew about PN (97.7%). 88.1% admitted using some over-the-counter substances. For PN purposes, coffee was used by 72.9% followed by energy drinks (68.2%) and cola drinks (62.4%). Methylxanthine containing tea was used for PN purposes, too (black tea 52.3%, green tea 51.7%). 1.8% admitted using illegal substances or prescription drugs, too. Discussion: Using legal methylxanthine containing drinks for PN seems to be extremely common with coffee and energy drinks being the preferred substances, while illegal and prescription drugs are only minimally used. Further studies should investigate the awareness of methylxanthine containing drinks as well as its character to be a flavoring drink or a neuroenhancer.

Methamphetamine withdrawal and the restoration of cognitive functions - a study over a course of 6 months abstinence.

A continuously rising consumption of methamphetamine (MA) has been suggested to be associated with increasing cognitive dysfunction. The objective of this study was to investigate associations between cognitive functions and gender, drug using patterns and treatment-attending profiles of recently abstinent MA users over the course of six months abstinence. Data were collected from 108 participants in two inpatient rehabilitation centers. The mean duration of MA use was 11.5 years. Interviews and cognitive tests (cognitrone, Stroop, TMT, nback) were performed right after the withdrawal and again after approx. six months of abstinence. Comparisons and explorative analyses between the groups (gender, primary MA/ multidrug users, early dropouts/ completers) regarding cognitive variables were performed. At baseline a significant decline in general neuropsychological functioning and attention/concentration after ongoing years of consumption were found. After a period of six months abstinence, cognitive performances remained stable or improved significantly for cognitrone percentile and cognitive flexibility. Normal cognitive functions were measured in former MA users after acute withdrawal which remained stable and partly improved in those patients who refrained from substance abuse over six months. Continued long-term MA intake was the only identified indicator of poorer cognitive performance. These results point towards a regain of cognitive performance in patients abstinent from MA.

Short-term changes in global methylation and hydroxymethylation during alcohol detoxification.

Alcohol dependence is a common public health problem and epigenetics may offer new aspects in understanding the biological and genetic underpinnings and improve treatment of this complex disease. Supposedly, methylation and hydroxymethylation are altered in brain tissues and in synapse-related genes due to chronic alcohol intake and during withdrawal. To assess potential epigenetic changes after cessation of chronic alcohol intake, we compared 23 alcohol-dependent individuals during inpatient alcohol detoxification with 13 carefully matched controls. Blood samples were taken on the day of admission, after one and after two weeks at the end of inpatient treatment. Genome-wide global methylation and global DNA hydroxymethylation were compared across groups. There were significant differences in global methylation across time from admission to one and two weeks of inpatient withdrawal (p < 0.001). These findings were paralleled to changes in global DNA hydroxymethylation across time when age was employed as a cofactor (p < 0.001). Several potentially influencing variables like severity of withdrawal, dose of withdrawal medication and alcohol intake before admission did not yield significant influence on epigenetic changes. The results confirm previous findings of significant alterations of epigenetic patterns during alcohol intoxication and present for the first time hydroxymethylation changes in these individuals.

Effects of stimulant drug use on the dopaminergic system: A systematic review and meta-analysis of in vivo neuroimaging studies.

BACKGROUND: Stimulant drugs can cause persistent changes in the brain. Imaging studies show that these changes are most apparent in dopamine transporter (DAT) or receptor availability within the striatum. METHODS: This work focuses on influences of stimulant use on dopaminergic function assessed using nuclear-medicine imaging (PET/SPECT). Included are 39 studies on 655 cocaine, amphetamine, methamphetamine or nicotine users, as well as 690 healthy controls. Metaanalyses were conducted separately for D2/D3 receptors and dopamine transporters of the entire striatum, its subregions caudate and putamen respectively. RESULTS: Meta-analyses results regarding nicotine did not show significant effects between smokers and nonsmokers. In cocaine users there was a significant decrease in dopamine receptor availability in all regions. The striatal DAT availability was significantly increased in cocaine users. Methamphetamine users showed a significantly decreased dopamine receptor and transporter density in all regions. Significant results also indicate a lower transporter availability in all regions. Amphetamine users showed reduced DAT availability in the striatum, as well as in the sub regions. CONCLUSION: This meta-analysis provides evidence that there are ongoing changes in the dopaminergic system associated with the use of stimulants. Especially the results of cocaine, methamphetamine and amphetamine use mainly showed a downregulation. In addition, this meta-analysis is the first to include nicotine. This subset of studies showed evidence for a decreased receptor and DAT availability but no significant results were found in the metaanalyses.

Effects of sedative drug use on the dopamine system: a systematic review and meta-analysis of in vivo neuroimaging studies.

Use of alcohol, cannabis and opioids is highly prevalent and is associated with global disease burden and high economic costs. The exact pathophysiology of abuse or addiction associated with these sedative substances is not completely understood, but previous research implicates the important role of the striatal dopamine system in the addiction process. Multiple studies investigated changes in the striatal dopamine systems of users of sedative substances, but currently these results are very heterogeneous. Therefore, we conducted a meta-analysis of in vivo neuroimaging studies investigating dopaminergic alterations in the striatum of users of alcohol, opioids or cannabis. Analyses for each substance were conducted separately for the availability of D2/D3 dopamine receptors, dopamine transporters and dopamine synthesis capacity. In total, 723 substance users and 752 healthy controls were included. The results indicated a significant lower striatal D2/D3 receptor availability in alcohol users compared to controls (g = 0.46) but no difference in dopamine transporter availability or dopamine synthesis capacity. Our analysis indicated that changes of dopamine receptors and transporters are moderated by the duration of abstinence. Comparing opioid users with controls revealed a significant lower D2/D3 receptor availability (g = 1.17) and a significantly lower transporter availability (g = 1.55) in opioid users. For cannabis users, there was no significant difference in receptor availability compared to controls and too few studies provided information on dopamine transporter availability or synthesis capacity. Our analysis provides strong evidence for a central role of the striatal dopamine system in use of alcohol or opioids. Further studies are needed to clarify the impact of the dopamine system in cannabis users.

The Impact of the Opioid Antagonist Naloxone on Experimentally Induced Craving in Nicotine-Dependent Individuals.

OBJECTIVE: Preclinical and clinical findings suggest a substantial association of the endogenous opioid system in nicotine dependence. The present study investigates the possible dose-dependent influence of naloxone, an unspecific opioid-receptor-antagonist, combined with cue exposure on the physiological state, locomotor activity, craving and the hypothalamic-pituitary-adrenal axis in nicotine-dependent humans. METHODS: Twenty nicotine-dependent, outpatient participants were deprived of nicotine for over 4 h, before receiving challenges with naloxone (1.6 mg or 3.2 mg q70 kg IV) or the placebo. Additionally, following drug administration, either smoking-related cues or neutral images were presented. Nicotine withdrawal was monitored by evaluating the following objective signs - skin conductance, heart rate, temperature, respiration, locomotor activity, cortisol, prolactin and ACTH levels as well as craving. RESULTS: With respect to subjective effects, participants administered a higher dosage of naloxone and those who were shown smoking-related cues were significantly less pleased (p = 0.019), felt more depressed (p = 0.033) and thought smoking would make them feel better (p = 0.028) than participants given naloxone and shown neutral cues. Participants given no naloxone but with smoking-related cues felt a higher urge to smoke than participants given naloxone and shown neutral cues (p = 0.042). Naloxone - in both dosages - also decreased the desire and intention to smoke in comparison to placebo. Compared to the placebo group, significantly higher cortisol, prolactin and ACTH values were observed after administration of lower and higher dosage of naloxone followed by smoking-related cues. CONCLUSION: Naloxone influenced nicotine withdrawal and strengthened significantly by cue exposure, both on objective measurement and on craving scales. These findings suggest an involvement of the endogenous opioid system in the development and maintenance of nicotine dependence.

Cognitive Deficits in Methamphetamine Users: How Strong is The Evidence?

Methamphetamine use has spread in many European countries and the United States. The current review provides a summary and critical analysis of research on cognitive deficits associated with methamphetamine, also known as "crystal meth." The literature search performed for this review led us to the hypothesis that methamphetamine use is associated with persistent changes in brain metabolism that result in various impairments, such as deficits in memory, attention, and concentration. The dopaminergic system in particular seems to be affected. Some studies indicate that cognitive impairments may improve when users become abstinent, but results of other studies are conflicting. This review discusses these findings and the consequences for the development of a specific addiction treatment for methamphetamine.

[Prevalence and Therapy of Crystal Methamphetamine Dependence]. / Prävalenz und Therapie bei Abhängigkeit von Methamphetamin ("Crystal").

Following a short overview on the epidemiology and clinical correlates of amphetamine abuse and dependence, with special emphasis on metamphetamine ("crystal"), current treatment concepts and recent results of therapy research are discussed. The efficacy of two inpatient treatment models for methamphetamine dependence are currently studied in a study funded by the German Ministry of health. The study concept is given and possible implications are discussed.