A Comprehensive Multi-Analyte Method for Hair Analysis: Substance-Specific Quantification Ranges and Tool for Task-Oriented Data Evaluation

The aim of the present study was to quantify a large number of analytes including opioids, stimulants, benzodiazepines, z-drugs, antidepressants and neuroleptics within a single sample workup followed by a single analytical measurement. Expected drug concentrations in hair are strongly substance dependent. Therefore, three different calibration ranges were implemented: 0.5 to 600 pg/mg (group 1), 10 to 12,000 pg/mg (group 2) and 50 to 60,000 pg/mg (group 3). In order to avoid saturation effects, different strategies were applied for selected transitions including the use of parent mass ions containing one or two 13C-isotopes and detuning of the declustering potential and/or collision energy. Drugs were extracted from pulverized hair by a two-step extraction protocol and measured by liquid chromatrography--tandem mass spectrometry (LC--MS-MS) using Scheduled MRM™ Algorithm Pro. In total, 275 MRM transitions including 43 deuterated standards were measured. The method has been fully validated according to international guidelines. A MultiQuant™ software based tool for task-oriented data evaluation was established, which allows extracting selected information from the measured data sets. The matrix effects and recoveries were within the allowed ranges for the majority of the analytes. The lower limits of quantification (LLOQs) were for ∼72% of the analytes in the low-pg/mg range (0.5-5 pg/mg) and for ∼24% of the analytes between 10 and 50 pg/mg. These LLOQs considered cut-offs by the Society of Hair Testing (SoHT), if recommended. The herein established multi-analyte approach meets the specific requirements of forensic hair testing and can be used for the rapid and robust measurement of a wide range of psychoactive substances. The analyte-specific wide concentration ranges open up a wide field of applications.

Insights into the Decontamination of Cocaine-Positive Hair Samples

A highly discussed step in hair sample preparation for forensic analytics is the applied decontamination. The here presented investigations aim to gain insight and give recommendations on how to conduct this decontamination for the analysis of cocaine consumption in hair. Key insights were gained from the investigation of cocaine consumer hair, which was artificially contaminated in a humid atmosphere with ¹³C₆ labelled cocaine and from cocaine powder contaminated hair. Several decontamination protocols were investigated, whereby the usage of a decontamination protocol consisting of multiple short repetitive washes allowed to visualize the wash out of (¹³C₆-) cocaine. Multiple methanol washes proved to be an efficient and simple decontamination approach. Our findings showed that decontamination protocols can successfully wash out recent cocaine contaminations. They were observed to be rather quickly washed out, whereas cocaine from consumption or “older” cocaine contaminations were shown to eliminate both at a constant rate (from inner hair compartments). Thus, the usage of decontamination protocols to differentiate between consumption and contamination was shown to be limited. As contamination can happen any time at any level, only the application of elaborated decision trees, based on cocaine metabolite ratios and thresholds, can provide the distinction between consumption and contamination. Thus, the authors highly recommend the usage of such tools on all hair samples analyzed for cocaine consumption.

Dextromethorphan Abuse Among Opioid-Dependent Patients

BACKGROUND

Among opioid-dependent patients on maintenance therapy, concomitant drug abuse is a serious problem. Dextromethorphan, an over-the-counter antitussive agent that can be purchased without prescription, is a drug with a high potential for misuse, especially when consumed in high doses.The objective of this study was to investigate possible abuse of dextromethorphan among substituted opioid-dependent patients and comparison of subjective and objective findings.Due to its ability to increase serotonin levels, opioid-dependent patients may be particularly susceptible to dextromethorphan misuse. Dextromethorphan misuse may have side effects, including psychiatric symptoms and serotonin syndrome, and may induce assault, suicide, or homicide.

METHODS

A total of 104 opioid-dependent patients in maintenance treatment were included in this cross-sectional study conducted in the outpatient department of the Psychiatric Hospital, University of Zurich. Study participants were divided into 2 groups based on laboratory results: dextromethorphan abusers (n = 12) and nonabusers (n = 92). The objective use and concentrations of dextromethorphan was detected using 3-month hair toxicology analysis.Statistical analysis was performed by using χ test, Student t test, Mann-Whitney U test, and Barnard exact test.

RESULTS

Dextromethorphan was abused by 12 (11.5%) patients, 11 (91.7%) of whom did not report concomitant abuse of dextromethorphan but were identified through hair analysis. In general, there were significant differences among patients abusing dextromethorphan compared with nondextromethorphan consumers in terms of trauma due to sexual maltreatment/violence, multiple traumas, or harmful use of hallucinogenic drugs.

CONCLUSIONS

Further studies are necessary to examine dextromethorphan and its impact on patients with psychiatric comorbidities and psychiatric medication. According to literature, there is a significant drug interaction risk due to the impact of dextromethorphan misuse on serotonin syndrome and psychiatric symptoms.1-3 We recommend active inquiry into and testing for concomitant drug abuse among substituted opioid-dependent patients to reduce the risk of drug interactions and side effects in this especially vulnerable group of patients.

LC-MS/MS Analysis of Δ9-THC, CBN and CBD in Hair: Investigation of Artefacts

In forensic toxicology, high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) is increasingly used for the fast and sensitive measurement of a wide range of drugs. For our routine casework, a liquid chromatography atmospheric pressure chemical ionization-tandem mass spectrometry (LC-APCI-MS/MS) method for the quantification of Δ9-tetrahydrocannabinol (Δ9-THC), cannabinol (CBN) and cannabidiol (CBD) in hair was established and fully validated. Separation was achieved using a Kinetex® C18 column (100 mm × 2.1 mm, 100 Å, 1.7 μm, Phenomenex) at a flow rate of 0.5 mL/min. Measurements were performed on a QTrap 5,500 mass spectrometer (Sciex, Darmstadt, Germany). Unexpected signals were observed in authentic THC-positive hair samples. First, a signal with a slightly shifted retention time of THC whose origin could be assigned to the isomer Δ8-THC. Second, additional peaks exhibiting the same fragments as CBN and Δ9-THC but eluting at different retention times were detected. Spiking experiments and enhanced product ion scans (EPI) pointed to the origin of these additional signals as result of in-source decarboxylation of Δ9-tetrahydrocannabinolic acid A (Δ9-THCA-A) into Δ9-THC and further partial oxidation of Δ9-THC into CBN, respectively. Positive findings of Δ9-THCA-A in hair have been shown to derive from external contamination, therefore, the herein described artefacts may be used as indirect markers for external contamination.

Cheating on forensic hair testing? Detection of potential biomarkers for cosmetically altered hair samples using untargeted hair metabolomics

Hair analysis has become an integral part in forensic toxicological laboratories for e.g. assessment of drug or alcohol abstinence. However, hair samples can be manipulated by cosmetic treatments, altering drug concentrations which eventually leads to false negative hair test results. In particular oxidative bleaching of hair samples under alkaline conditions significantly affects incorporated drug concentrations. To date, current techniques to detect cosmetic hair adulterations bear limitations such as the implementation of cut-off values or the requirement of specialized instrumentations. As a new approach, untargeted hair metabolomics analysis was applied to detect altered, endogenous biomolecules that could be used as biomarkers for oxidative cosmetic hair treatments. For this, genuine hair samples were treated in vitro with 9% hydrogen peroxide (H2O2) for 30 minutes. Untreated and treated hair samples were analyzed using liquid-chromatography high-resolution time-of-flight mass spectrometry. In total, 69 metabolites could be identified as significantly altered after hair bleaching. The majority of metabolites decreased after bleaching, yet totally degraded metabolites were most promising as suitable biomarkers. The formation of biomarker ratios of metabolites decreasing and increasing in concentrations improved the discrimination of untreated and treated hair samples. With the results of this study, the high variety of identified biomarkers now offers the possibility to include single biomarkers or biomarker selections into routine screening methods for improved data interpretation of hair test results.

Use of levamisole-adulterated cocaine is associated with increased load of white matter lesions

Background

Cocaine use has been associated with vascular pathologies, including cerebral white matter hyperintensities. Street cocaine is most often adulterated with levamisole, an anthelminthic drug that may also be associated with vascular toxicity. However, whether levamisole exposure from cocaine consumption further accelerates the development of white matter lesions remains unknown.

Methods

We investigated the association of cocaine and levamisole exposure with white matter hyperintensities in 35 chronic cocaine users and 34 healthy controls. We measured cocaine and levamisole concentrations in hair samples, which reflected exposure up to 6 months previously. We assessed the number and total surface area of the white matter hyperintensities using structural MRI (FLAIR sequence). Using generalized linear models, we analyzed the contributions of cocaine and levamisole to the number and area of white matter hyperintensities, accounting for several confounding factors.

Results

Analysis using generalized linear models revealed that cocaine users had more white matter hyperintensities in terms of total surface area, but not in terms of number. Further generalized linear models that included cocaine and levamisole hair concentrations (instead of group) as predictors indicated that levamisole exposure was strongly associated with more and larger white matter hyperintensities, suggesting that the elevated white matter hyperintensities in cocaine users were driven mainly by levamisole exposure. Finally, white matter hyperintensities in levamisole-exposed cocaine users were located primarily in the periventricular and juxtacortical white matter.

Limitations

The sample size was moderate, and blood pressure was not systematically assessed.

Conclusion

As an adulterant of cocaine, levamisole appears to increase the risk of white matter injury.

Chronic non-medical prescription opioid use and empathy for pain: Does pain make the difference?

Non-medical prescription opioid use (NMPOU) is at the heart of the opioid epidemic in the United States. Although chronic opioid use is commonly accompanied by deficits in social functioning, little is known about the impact of chronic NMPOU on social cognitive functions. Social neuroscience models suggest that empathy activates similar or even equivalent neural structures as those underpinning the first-hand experience in that emotional state (e.g., pain). Therefore, we measured subjective and psychophysiological responses during an empathy-for-pain task in 23 individuals with NMPOU, objectively confirmed by hair and urine testing, and compared them with 29 opioid-naïve healthy controls. NMPOU individuals showed lower other-related and self-related unpleasantness ratings when seeing others in pain than controls. No differences between the control and NMPOU group were found in skin conductance responses and heart rate variability (HRV) assessed by root mean square of successive differences (RMSSD) in response to the task. However, RMSSD-HRV was strongly negatively correlated with self-related unpleasantness and craving in the NMPOU group. A subsequent mediation analysis showed a total effect of RMSSD-HRV on self-related unpleasantness with no mediation of craving. This indicates that stronger emotion regulation indexed by high RMSSD-HRV might have downregulating effects on sharing others' pain in NMPOU individuals but not in healthy controls, which was further accompanied by decreased ratings of personal distress and empathetic concern. These results contribute to a better understanding of social functioning in chronic opioid users, suggesting adequate emotion regulation and empathy trainings as therapeutic targets for future interventions of opioid use disorders and long-term pain treatment with opioids.

Use of Ethanol-Based Hand Disinfectants: Source of Increased Ethyl Glucuronide Levels in Hair?

Aim

Due to the COVID-19 pandemic increasing the use of hand disinfectants, we investigated the effect of frequent use of ethanol-based hand disinfectants (EBHD) on the levels of the alcohol marker ethyl glucuronide (EtG) in hair.

Method

Hair samples were collected from 10 health professionals (8 nondrinkers, 2 rarely drinking individuals) and EtG was examined in hair.

Result

EtG (~2 pg/mg) was only detected in the hair sample of a nondrinker using EBHD 60–70 times per working day.

Conclusion

Our data provide no evidence that frequent EBHD use results in hair EtG levels above the recommended Society of Hair Testing cutoff for repeated alcohol consumption (5 pg/mg).

Simultaneous quantification of steroid hormones and endocannabinoids (ECs) in human hair using an automated supported liquid extraction (SLE) and LC-MS/MS - Insights into EC baseline values and correlation to steroid concentrations

Endogenous steroid hormones and endocannabinoids (ECs) are important regulators in the stress response of the human body. For the measurement of chronic stress, hair analysis has been established as method of choice for long-term and retrospective determination of endogenous stress markers. A sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of five steroid hormones (cortisone, cortisol, androstenedione, testosterone, progesterone) and four endocannabinoids (anandamide, palmitoylethanolamide, 2-arachidonylglycerol, oleoylethanolamide) in hair was developed and validated. The hair samples were extracted with methanol and cleaned up with a fully automated supported liquid extraction (SLE) before analysis. Special attention was paid to the difficulties accompanying the quantification of endogenous analytes in hair. Five different strategies for endogenous compound quantification in hair (surrogate analyte, standard addition, background correction, stripped matrix and solvent calibration) were tested and compared. As a result, the approach of the surrogate analyte was used for the quantification of steroid hormones whereas background correction was used for endocannabinoids. The measurement of 58 samples from healthy young adults allowed insights into endocannabinoid ranges in hair and the correlation to steroid hormones. No significant differences in steroid and EC concentration levels of male and female in hair were found, except for testosterone (p < 0.001) and androstenedione (p < 0.0001). Cortisol to cortisone and testosterone to androstenedione concentrations were significantly and positively correlated. There were significant intercorrelations between endocannabinoids.

Using time-of-flight secondary ion mass spectrometry (ToF-SIMS) and matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) for investigations on single hair samples to solve the contamination versus incorporation issue of hair analysis in the case of cocaine and methadone

Drug testing in hair is a controversial subject of discussion. Claims that decontamination protocols could generate false-positive samples, by washing contamination in hair, have unsettled many toxicologists. At least for zolpidem (known for showing only minor contamination), it could be shown that differentiation of the drug incorporated via the bloodstream from contamination was possible. The current work addresses cocaine and methadone, known for their high concentrations and contamination issues. Longitudinally and cross-sectioned samples of drug-soaked hair, consumer hair and cocaine powder contaminated hair were investigated using time of flight-secondary ion mass spectrometry (ToF-SIMS) and matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). In addition, the resulting wash solutions were investigated using LC-MS/MS. Differentiation of contamination from incorporation was possible for soaked and consumer hair samples. Therefore, contamination could be localized in the superficial compartments of hair and could be removed using strong wash protocols. In the case of powder contaminated hair samples, a small amount of cocaine remained in the inner structures even after the application of the strongest wash protocols. However, taking into consideration the differences in their behavior during decontamination steps compared to both soaked and authentic hair samples, the validity of this contamination protocol (rubbing cocaine powder into hair) must be questioned. Furthermore, when using cut-off values and metabolite ratios (from routine hair analysis), the differentiation of incorporation from contamination was possible also for all our experimental samples in this study. Inclusion of metabolites and application of cut-off values are therefore a must in routine hair analysis.

Cocaine Hydroxy Metabolites in Hair: Indicators for Cocaine Use Versus External Contamination☆

Given that external contamination must be considered in hair analysis, there is still a demand for reliable tools to differentiate between incorporation of drugs into the hair as a result of drug consumption and of the hair shaft by external contamination. With the aim of establishing alternative discrimination parameters, some of the hydroxy metabolites of cocaine i.e., para- and meta-hydroxycocaine and para- and meta-hydroxybenzoylecgonine were measured together with cocaine, benzoylecgonine, cocaethylene, and norcocaine in five seized street cocaine samples and in hair samples from different cohorts: cohort 1 (in vivo external contamination study, n = 28), cohort 2 (individuals with self-reported cocaine use, n = 92), and cohort 3 (individuals with suspected cocaine use or contamination, n = 198). Statistical evaluation of the data of cohort 1 and 2 using ROC curves yielded metabolic ratios indicating cocaine use. Based on these results, a decision workflow was established for the discrimination between cocaine use and external contamination. The power of this approach was finally statistically validated across the different cohorts.

Psychiatric symptoms and expression of glucocorticoid receptor gene in cocaine users: A longitudinal study

BACKGROUND

Chronic cocaine users (CU) display reduced peripheral expression of the glucocorticoid receptor gene (NR3C1), which is potentially involved in stress-related psychiatric symptoms frequently occurring in CU. However, it is unknown whether psychiatric symptoms and lower NR3C1 expression are related to each other and whether reduction of drug consumption reverse them.

METHOD

At baseline, NR3C1 mRNA expression was measured in 68 recreational CU, 30 dependent CU, and 68 stimulant-naïve controls. Additionally, the Revised Symptom Checklist (SCL-90R) and the Barratt Impulsiveness Scale (BIS) were assessed. At a one-year follow-up, the association between change in NR3C1 expression and psychiatric symptoms was examined in 48 stimulant-naïve controls, 19 CU who increased and 19 CU who decreased their consumption. At both test sessions, cocaine concentrations in hair samples were determined. Mixed-effects models were used to investigate how changes in drug use intensity affect severity of psychiatric symptoms and NR3C1 expression over time.

RESULTS

At baseline, recreational and dependent CU displayed elevated impulsivity and considerable symptom burden across most of the SCL-90R subscales. Time-group interaction effects were found for several impulsivity scores, SCL-90R Global Severity Index, Paranoid Thoughts, and Depression subscales as well as for NR3C1 expression. Pairwise comparisons showed that decreasing CU specifically improved in these SCL-90R subscales, while their NR3C1 expression was adapted. Finally, changes in NR3C1 expression were negatively correlated with changes in impulsivity but not SCL-90R scores.

CONCLUSION

Our findings suggest that NR3C1 expression changes and some psychiatric symptoms are reversible upon reduction of cocaine intake, thus favouring abstinence-oriented treatment approaches.

Endogenous steroid hormones in hair: Investigations on different hair types, pigmentation effects and correlation to nails

Steroid hormone analysis is widely used in health- and stress-related research to get insights into various diseases and the adaption to stress. Hair analysis has been used as a tool for the long-term monitoring of these steroid hormones. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous identification and quantification of seven steroid hormones (cortisone, cortisol, 11-deoxycortisol, androstenedione, 11-deoxycorticosterone, testosterone, progesterone) in hair. Cortisol, cortisone, androstenedione, testosterone and progesterone were detected and quantified in authentic hair samples of different individuals. Significantly higher concentrations for body hair were found for cortisone and testosterone compared to scalp hair. Furthermore, weak correlations for the majority of steroids between scalp and body hair indicate that body hair is not really suitable as alternative when scalp hair is not available. The influence of hair pigmentation was analyzed by comparing pigmented to non-pigmented hair of grey-haired individuals. The results showed no differences for cortisol, cortisone, androstenedione, testosterone and progesterone concentrations (p > 0.05) implying that hair pigmentation has not a strong effect on steroid hormone concentrations. Correlations between hair and nail steroid levels were also studied. Higher concentrations of cortisol and cortisone in hair were found compared to nails (p < 0.0001). No significant correlation for cortisone, cortisol, androstenedione, testosterone and progesterone concentrations were found between hair and nails. These results demonstrate that matrix-dependent value ranges for hair and nail steroid levels should be established and applied for interpretation.

A possible new oxidation marker for hair adulteration: Detection of PTeCA (1H-pyrrole-2,3,4,5-tetracarboxylic acid) in bleached hair

Hair analysis has become a valuable tool in forensic toxicology to assess drug or alcohol abstinence. Yet, hair adulteration by cosmetic products presents a major challenge for forensic hair analysis. Oxidative treatments, e.g. bleaching, may lead to analyte loss and thereby to false negative results. Currently, the eumelanin degradation product 1H-pyrrole-2,3,5-tricarboxylic acid (PTCA) serves as a marker for oxidative hair treatment, but requires the definition of cut-off values. To investigate further eumelanin degradation products as markers for oxidative hair treatment, hair samples with and without in vitro bleaching (hydrogen peroxide (H₂ O₂ ) concentrations 1.9% up to 12%; incubation times 15 min, 30 min, 60 min) were analyzed by liquid chromatography coupled to high-resolution time of flight mass spectrometry (HPLC-HRMS). The distribution of eumelanin degradation products along the hair shaft was investigated for routine applicability after segmentation of cosmetically untreated hair samples and authentically treated hair samples. The signals of the eumelanin degradation products PTCA, 1H-pyrrole-2,3,4-tricarboxylic acid (isoPTCA), and 1H-pyrrole-2,3,4,5-tetracarboxylic acid (PTeCA) were found to be significantly elevated after in vitro bleaching already with low H₂ O₂ concentrations and after short incubation times. In contrast to PTCA and isoPTCA, PTeCA was not detectable in cosmetically untreated segments up to 12 cm from hair root and was only formed through the oxidation process. The results of the study show that the detection of PTeCA within the proximal 3 to 6 cm segment can be applied to reliably detect hair adulteration attempts through hair bleaching.

Nocturnal Gamma-Hydroxybutyrate Reduces Cortisol-Awakening Response and Morning Kynurenine Pathway Metabolites in Healthy Volunteers

BACKGROUND

Gamma-hydroxybutyrate (GHB; or sodium oxybate) is an endogenous GHB-/gamma-aminobutyric acid B receptor agonist. It is approved for application in narcolepsy and has been proposed for the potential treatment of Alzheimer's disease, Parkinson's disease, fibromyalgia, and depression, all of which involve neuro-immunological processes. Tryptophan catabolites (TRYCATs), the cortisol-awakening response (CAR), and brain-derived neurotrophic factor (BDNF) have been suggested as peripheral biomarkers of neuropsychiatric disorders. GHB has been shown to induce a delayed reduction of T helper and natural killer cell counts and alter basal cortisol levels, but GHB's effects on TRYCATs, CAR, and BDNF are unknown.

METHODS

Therefore, TRYCAT and BDNF serum levels, as well as CAR and the affective state (Positive and Negative Affect Schedule [PANAS]) were measured in the morning after a single nocturnal dose of GHB (50 mg/kg body weight) in 20 healthy male volunteers in a placebo-controlled, balanced, randomized, double-blind, cross-over design.

RESULTS

In the morning after nocturnal GHB administration, the TRYCATs indolelactic acid, kynurenine, kynurenic acid, 3-hydroxykynurenine, and quinolinic acid; the 3-hydroxykynurenine to kynurenic acid ratio; and the CAR were significantly reduced (P < 0.05-0.001, Benjamini-Hochberg corrected). The quinolinic acid to kynurenic acid ratio was reduced by trend. Serotonin, tryptophan, and BDNF levels, as well as PANAS scores in the morning, remained unchanged after a nocturnal GHB challenge.

CONCLUSIONS

GHB has post-acute effects on peripheral biomarkers of neuropsychiatric disorders, which might be a model to explain some of its therapeutic effects in disorders involving neuro-immunological pathologies. This study was registered at ClinicalTrials.gov as NCT02342366.

Hair Analysis: Contamination versus Incorporation from the Circulatory System-Investigations on Single Hair Samples Using Time-of-Flight Secondary Ion Mass Spectrometry and Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

Contamination is a highly controversial issue in hair analysis. Therefore, hair testing protocols typically include wash steps to remove contamination. However, recent studies claim that washing could also lead to permanent incorporation of contaminants into hair, thus questioning the validity of hair testing at all. In the present study, matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) with longitudinal sectioning of single hairs and different decontamination protocols was used to reveal differences between the incorporation of a substance into hair from external sources and an incorporation via bloodstream. Single hairs were longitudinally sectioned using a custom-made sample holder. Data were acquired with MALDI-MS by rastering each hair individually. Single hair samples from drug users, blank hairs, and zolpidem- and zolpidem-D6-soaked hairs were investigated. Different published washing protocols were tested, and an in-house washing protocol was developed. For images with higher spatial resolution, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used. Longitudinal sectioning of hairs dramatically increased sensitivity; even single-dose administrations of zolpidem in single hairs could thus be detected using MALDI-MS. Zolpidem from external sources could be detected in large quantities in superficial hair structures. Zolpidem from consumer hairs, proposed to be strongly bound to inner hair structures, could not be completely removed even by the strongest tested decontamination protocol, whereas zolpidem-soaked hairs could be cleared almost completely with the developed in-house wash protocol. The applied methods allowed a first insight into the connection of decontamination protocols and wash-in phenomena in hair analysis. Further studies with other drugs are necessary to assess the general validity of these findings.

Non-medical prescription opioid users exhibit dysfunctional physiological stress responses to social rejection

Non-medical prescription opioid use (NMPOU) recently increased dramatically, especially in the U.S. Although chronic opioid use is commonly accompanied by deficits in social functioning and dysregulation of the hypothalamic-pituitary adrenergic (HPA) stress axis, little is known about the impact of NMPOU on psychosocial stress responses. Therefore, we measured physiological responses of the autonomic nervous system and the HPA axis to social rejection using the Cyberball paradigm. We compared 23 individuals with NMPOU, objectively confirmed by hair and urine analyses, with 29 opioid-naïve, healthy controls. As expected, heart rate variability (HRV), an index of parasympathetic activity, increased significantly during exclusion within controls, while in the NMPOU group only a trend in the same direction was found. However, increased HRV was robustly moderated by opioid craving indicating worse emotion regulation to social exclusion specifically in individuals with high opioid craving. Greater levels of the adrenocorticotropic hormone and cortisol responses to social rejection were found in the NMPOU group indicating hyperreactivity of the HPA axis to social exclusion. Self-ratings suggest that opioid users were aware of rejection, but less emotionally affected by exclusion. Furthermore, controls showed greater negative mood after the Cyberball confirming the task's validity. Moreover, NMPOU individuals reported a smaller social network size compared to controls. Present findings suggest that chronic NMPOU is associated with dysfunctional physiological responses to psychosocial stressors such as social rejection. In sum, NMPOU was associated with poorer regulation of the parasympathetic nervous system, especially under opioid craving highlighting its potential importance in relapse prevention.

Longitudinal changes in cocaine intake and cognition are linked to cortical thickness adaptations in cocaine users

BACKGROUND

Cocaine use has been consistently associated with decreased gray matter volumes in the prefrontal cortex. However, it is unclear if such neuroanatomical abnormalities depict either pre-existing vulnerability markers or drug-induced consequences. Thus, this longitudinal MRI study investigated neuroplasticity and cognitive changes in relation to altered cocaine intake.

METHODS

Surface-based morphometry, cocaine hair concentration, and cognitive performance were measured in 29 cocaine users (CU) and 38 matched controls at baseline and follow-up. Based on changes in hair cocaine concentration, CU were classified either as Decreasers (n = 15) or Sustained Users (n = 14). Surface-based morphometry measures did not include regional tissue volumes.

RESULTS

At baseline, CU displayed reduced cortical thickness (CT) in lateral frontal regions, and smaller cortical surface area (CSA) in the anterior cingulate cortex, compared to controls. In Decreasers, CT of the lateral frontal cortex increased whereas CT within the same regions tended to further decrease in Sustained Users. In contrast, no changes were found for CSA and subcortical structures. Changes in CT were linked to cognitive performance changes and amount of cocaine consumed over the study period.

CONCLUSIONS

These results suggest that frontal abnormalities in CU are partially drug-induced and can recover with decreased substance use. Moreover, recovery of frontal CT is accompanied by improved cognitive performance confirming that cognitive decline associated with cocaine use is potentially reversible.

Concomitant Heroin and Cocaine Use among Opioid-Dependent Patients during Methadone, Buprenorphine or Morphine Opioid Agonist Therapy

BACKGROUND

Among all the treatment methods developed so far, opioid agonist treatment (OAT) is the most effective therapy for opioid dependence. While methadone (MTD) is the most commonly used, fewer data are available on alternative opioid agonist. The aim of this study was to assess the efficacy of buprenorphine (BUP) and slow-released morphine compared to MTD with regard to the reduction of concomitant heroin and cocaine use.

METHODS

This cross-sectional study included 105 patients receiving MTD, BUP, or slow-release morphine as opioid agonist therapy at the Psychiatric Hospital of Zurich. Illicit drug use was assessed using a retrospective 3-month hair toxicology analysis to quantify concentrations of heroin degradation products and metabolites, as well as cocaine and cocaine metabolites. We have also collected self-reports, but in the data of the study, only the results of the hair analysis were considered.

RESULTS

BUP-treated patients showed lower rates of illicit opiate consumption in comparison to the group treated with MTD or slow-released morphine (p < 0.05). The proportion of heroin-positive hair samples associated with slow-release morphine treatment was similar to the proportion associated with MTD treatment. Neither the MTD vs. slow-released morphine groups nor the BUP vs. MTD groups showed significant differences in the number of patients consuming cocaine although patients in the BUP group had significantly lower concentrations of cocaine in hair testing compared to the patients in the MTD group. Prevalence of cocaine consumption was also significantly lower in the BUP group compared to patients in the slow-release morphine group (p < 0.05).

CONCLUSION

This study suggests that BUP OAT is associated with reduced additional opiate co-use.

Cognitive and socio-cognitive functioning of chronic non-medical prescription opioid users

RATIONALE

Non-medical prescription opioid use (NMPOU) has become a major public health issue in the USA and is also increasing in Europe. However, little is known about neuropsychological associations of NMPOU-specifically regarding social cognition, which is essential for social functioning and treatability of opioid dependence. Previous studies with heroin users and opioid-substituted patients reported deficits in various cognitive functions, but these results are likely confounded by comorbid physical and psychiatric diseases, overdose-associated hypoxia, and adulteration of street heroin. Therefore, the purpose of the present study was to investigate social and non-social cognition in a relatively pure NMPOU sample taking opioid analgesics or antitussives.

METHODS

We assessed 23 individuals with NMPOU objectively confirmed by hair analyses and 29 opioid-naïve, healthy controls, employing a comprehensive neuropsychological test battery.

RESULTS

Significant impairments were found between NMPOU individuals and controls regarding the cognitive domains of attention (p < .01, Hedge's g = .85), declarative memory (p < .05, g = .66), and global cognitive empathy (p < .01, g = 0.99)-the latter included problems with emotion recognition from faces, voices, and complex scenes. Opioid hair concentrations transformed to morphine equivalents were negatively correlated with global cognitive empathy (r = - 0.52, p < .01), suggesting dose-dependent deficits.

CONCLUSION

In contrast to stimulant users primarily displaying deficits in emotional empathy, opioid users showed relatively selective impairments in measures of cognitive empathy, with dose-dependent effects suggesting potential opioid-induced deficits and involvement of the opioid-system in processes of cognitive empathy. These results have important implications for future interventions of opioid dependence targeting social functioning and consequently enhancing therapy outcome and preventing relapse.

Steroid profiling in nails using liquid chromatography-tandem mass spectrometry

The retrospective analysis of endogenous steroid hormones in nails can be used to elucidate endocrine diseases and thus help with their diagnosis and treatment. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) based method was developed for the simultaneous identification and quantification of 12 steroid hormones (aldosterone, cortisone, cortisol, corticosterone, 11-deoxycortisol, androstenedione, 11-deoxycorticosterone, testosterone, dehydroepiandrosterone (DHEA), 17α-hydroxyprogesterone (17-OHP), dihydrotestosterone (DHT) and progesterone) in human fingernails. Steroid hormones were extracted from 0.5 mg to 10 mg pulverized nail clippings by methanolic extraction, followed by a liquid-liquid extraction. The analysis was conducted with LC-MS/MS in electrospray ionization positive mode. The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, matrix effect, recovery and robustness. It was successfully applied for steroid profiling in nails of mothers and their infants where cortisol, cortisone, testosterone, progesterone, androstenedione and 11-deoxycorticosterone could be detected. Furthermore, it could be shown that there is no significant difference in concentrations between left and right hand for cortisol, cortisone and progesterone. A positive linear correlation between cortisol and cortisone in nails was found. In conclusion, it could be shown that nails are a suitable matrix for the retrospective monitoring of cumulative steroid hormone levels.

Self-regulation of the dopaminergic reward circuit in cocaine users with mental imagery and neurofeedback

BACKGROUND

Enhanced drug-related reward sensitivity accompanied by impaired sensitivity to non-drug related rewards in the mesolimbic dopamine system are thought to underlie the broad motivational deficits and dysfunctional decision-making frequently observed in cocaine use disorder (CUD). Effective approaches to modify this imbalance and reinstate non-drug reward responsiveness are urgently needed. Here, we examined whether cocaine users (CU) can use mental imagery of non-drug rewards to self-regulate the ventral tegmental area and substantia nigra (VTA/SN). We expected that obsessive and compulsive thoughts about cocaine consumption would hamper the ability to self-regulate the VTA/SN activity and tested if real-time fMRI (rtfMRI) neurofeedback (NFB) can improve self-regulation of the VTA/SN.

METHODS

Twenty-two CU and 28 healthy controls (HC) were asked to voluntarily up-regulate VTA/SN activity with non-drug reward imagery alone, or combined with rtfMRI NFB.

RESULTS

On a group level, HC and CU were able to activate the dopaminergic midbrain and other reward regions with reward imagery. In CU, the individual ability to self-regulate the VTA/SN was reduced in those with more severe obsessive-compulsive drug use. NFB enhanced the effect of reward imagery but did not result in transfer effects at the end of the session.

CONCLUSION

CU can voluntary activate their reward system with non-drug reward imagery and improve this ability with rtfMRI NFB. Combining mental imagery and rtFMRI NFB has great potential for modifying the maladapted reward sensitivity and reinstating non-drug reward responsiveness. This motivates further work to examine the use of rtfMRI NFB in the treatment of CUD.

Cognitive and neuroanatomical impairments associated with chronic exposure to levamisole-contaminated cocaine

Currently, levamisole is the most common cocaine adulterant worldwide and it is known to induce a variety of adverse side effects. Animal studies and human case reports suggest potential neurotoxicity of the compound but neither neuroanatomical nor cognitive effects of levamisole have been systematically investigated in cocaine users so far. We examined cognitive performance and cortical structural differences between chronic cocaine users with low and high recent exposure to levamisole objectively determined by quantitative toxicological hair analyses. In Study 1, we compared 26 chronic cocaine users with low levamisole exposure (lowLevCU), 49 matched cocaine users with high levamisole exposure (highLevCU), and 78 matched stimulant-naive controls regarding cognitive functioning employing a comprehensive neuropsychological test battery. In Study 2, we investigated cortical thickness by use of T1-weighted MRI in a subgroup of 12 lowLevCU, 17 highLevCU, and 38 stimulant-naive controls. In Study 1, both cocaine user groups showed significant impairments in the cognitive domains of attention and working memory as well as in the global cognitive index. However, highLevCU showed significantly worse executive functions compared to lowLevCU although both groups did not differ in severity of cocaine consumption and other clinical dimensions. Study 2 revealed that highLevCU, displayed reduced cortical thickness specifically in the middle frontal gyrus compared to both controls and lowLevCU. Our results suggest that levamisole exposure during the last months in cocaine users is associated with increased executive function impairments and pronounced thinning of the lateral prefrontal cortex. Consequently, prevention and drug policy-making should aim to reduce levamisole contamination of street cocaine.

Cocaine adulteration with the anthelminthic tetramisole (levamisole/dexamisole): Long-term monitoring of its intake by chiral LC-MS/MS analysis of cocaine-positive hair samples

Recent studies indicate that not only the anthelminthic levamisole but also the racemate tetramisole (R-/S-phenyltetraimidazothiazole, PTHIT) was found as an adulterant for cocaine. We herein report on the investigation of the prevalence of PTHIT among cocaine-positive hair samples and the discrimination of the presence of its stereoisomers levamisole and dexamisole. Cocaine-positive hair samples were collected in a forensic context in 2015 and mainly 2017 (n = 724). Cocaine and PTHIT concentrations have been determined by achiral liquid chromatography-tandem mass spectrometry (LC-MS/MS). For distinction of levamisole/dexamisole chiral LC-MS/MS was performed. Cocaine hair concentrations ranged from 500 (cut-off) to approximately 800 000 pg/mg. The study demonstrates a strong prevalence of PTHIT in cocaine users' hair (87%, n = 627). PTHIT hair concentrations ranged from below LLOQ 3.5 to approximately 61 000 pg/mg (median: 260 pg/mg). Surprisingly, enantiomeric ratios of levamisole/dexamisole ranged from 0.17 to 1.34 (median: 0.63). Therefore, PTHIT-adulterated street cocaine samples (n = 24) seized between 2013 and 2016 were tested. Samples mainly contained racemic tetramisole (87.5%), only one sample contained levamisole only and two samples contained non-racemic PTHIT. Our experiments suggest that the presence of tetramisole in biological samples may have hitherto been underestimated. Most probably higher dexamisole than levamisole concentrations in hair specimens arise from stereoselective metabolism and/or elimination. This is particularly important in light of the different pharmacological activities of the two enantiomers and potentially different adverse effects. Toxicological interpretations in intoxication cases with adulterated cocaine should not only consider levamisole but also tetramisole and terminology in scientific contributions should be used accordingly.