Evidence-based analysis of the worldwide abuse of licit and illicit drugs

Cannabinoids in the Orthopedic Setting: A Literature Review

Public interest in the analgesic potential of cannabinoids has grown, but there is no consensus regarding orthopedic applications. Available evidence was identified for cannabinoid use in arthritis, neuropathic pain, fibromyalgia, multiple sclerosis, and postoperative pain. Extracted information included the risks of preoperative use, associations with opioid dependence, and surgical complications. There is limited evidence for therapeutic benefit of cannabinoids in rheumatoid arthritis and fibromyalgia. Cannabinoids are not indicated for postoperative pain. Preoperative unregulated use has been linked with postoperative opioid dependence. Cannabinoids may be considered a second- or third-line treatment for analgesia for some orthopedic pathologies. [Orthopedics. 2022;45(4):e183-e189.].

In Vitro Selection of Short DNA Aptamers that Can Inhibit or Alleviate Cocaine and MK-801 Inhibition of Muscle-Type Nicotinic Acetylcholine Receptors

Ligands of high specificity and selectivity have been selected for biological molecules of interest including nicotinic acetylcholine receptor (nAChR) using combinatorial libraries of nucleic acids. The nAChR belongs to a group of structurally related proteins that regulate signal transmission between ~ 10¹² cells of the mammalian nervous system. It is inhibited by both therapeutic agents and abused drugs, including cocaine. A mechanism-based approach to alleviating noncompetitive inhibition of the mucle-type nAChR, including Torpedo, resulted in the selection of very short DNA aptamers only seven nucleotides long. By transient kinetic measurements, these DNA aptamers, which displaced cocaine from its binding site on the muscle-type nAChR, were classified into two groups based on their effects on the nAChR: Class I aptamers inhibit agonist-induced current in the muscle-type nAChR and Class II molecules alleviate inhibition by MK-801 [(+)-dizocilpine] without affecting the receptor function. The most potent Class I DNA aptamer, which inhibits the muscle-type nAChR, has an apparent dissociation constant (K_Iapt) of 5 μM, while the most efficient Class II DNA aptamer, which alleviates MK-801-induced inhibition, has an apparent dissociation constant (K_Apt) of 1.8 μM. An innovative aspect of the work is the identification of very short DNA aptamers with these properties that makes them attractive for therapeutic and diagnostic applications.

Differential effects of cannabis exposure during early versus later adolescence on the expression of psychosis in homeless and precariously housed adults

Longitudinal studies of cannabis exposure during early adolescence in the general population frequently report an increased risk of subsequently developing psychotic symptoms or a psychotic illness. However, there is a dearth of knowledge about the effects of early cannabis exposure on psychosis in homeless and precariously housed adults, who represent a population afflicted with high rates of psychosis. The aim of the present study was to examine how early cannabis exposure (by age 15) compared to later first use (after age 15) affected the expression of adult psychosis in this population. Secondary measures of psychopathology, drug use, cognition and brain structure were also collected. 437 subjects were recruited from single room occupancy hotels in the urban setting of the Downtown Eastside of Vancouver, Canada. Psychiatric diagnoses were determined, and psychotic symptom severity was measured with the 5-factor PANSS. Participants completed a battery of neurocognitive tests, and brain structure was assessed using structural and diffusion tensor imaging MRI scans. Results indicated that early cannabis exposure was associated with an increased risk (OR = 1.09, p < .05) of developing substance induced psychosis, whereas later first use increased risk (OR = 2.19, p < .01) of developing schizophrenia or schizoaffective disorder. There was no group difference in neurocognitive function, although differences were observed in the lateral orbitofrontal cortex and white matter tract diffusivity. These findings indicate that early cannabis exposure in this population may increase the risk of developing drug associated psychoses, which could potentially be mediated in part through altered neurodevelopmental brain changes.

Predictors and consequences of incarceration among a sample of young Thai methamphetamine users

INTRODUCTION AND AIMS

Our study examined the incidence of arrest and incarceration, investigated predictors of incarceration and explored the persistence of depression, alcohol use and drug use after incarceration among young methamphetamine users from Thailand.

DESIGN AND METHODS

Participants were aged 18-25 years old and were a part of a 12 month randomised social network trial that aimed to reduce sexual risk and methamphetamine use. Estimates of the incidence of arrest and incarceration over 12 months were calculated. A matched case-control study (n = 73 cases; n = 223 controls) was performed to examine incarceration risk factors using conditional logistic regression. Persistence of drug-risk behaviours were explored after incarceration.

RESULTS

Study participants (n = 950) were 72% male, with a median age of 19 years and a median of 9 years of schooling. Frequent drug and alcohol use were reported at baseline. In total, 35% of the sample reported ever having been arrested and 22% reported ever having been incarcerated at baseline. During the 12 month follow up, 16% of the sample was arrested. In univariate analyses, risk factors for incarceration included frequent drug and alcohol use, being less educated, and a history of arrest and incarceration. A high prevalence of drug and alcohol use and involvement in the drug economy persisted after arrest.

DISCUSSION AND CONCLUSIONS

The study indicates a high prevalence of recidivism among this young sample, with continued involvement in drug-risk behaviours after incarceration. Appropriate interventions are needed to address root causes of arrest, largely related to substance use.

Reasons for cannabis use in men with and without psychosis

Psychoses are relatively low prevalence disorders that have a disproportionately negative impact on individuals and society. Cannabis use is one factor that can exacerbate the negative consequences associated with psychotic disorders. Relatively few studies have examined the effects or reasons for using cannabis self-reported by individuals with psychosis. The present study is the first known to compare directly such factors in individuals with and without psychosis, within a single study. At baseline and follow-up participants with psychosis most commonly reported using cannabis for positive mood alteration (36% and 42%), coping with negative affect (27% and 29%) and for social activity reasons (38% and 29%). The control group most commonly reported using cannabis for relaxation (34% and 43%) and social activity reasons (49% and 51%). Participants with psychosis were less likely to report relaxation as the most important effect after use (27%) or expect it at follow-up (49%) compared to the control group (53% and 70%). In both groups, addiction and positive affect enhancement were the composite variable scores correlated most consistently with concurrent amount and frequency of use.

Effects of cocaine, methamphetamine and modafinil challenge on sleep rebound after paradoxical sleep deprivation in rats

Sleep loss is both common and critically relevant to our society and might lead to the abuse of psychostimulants such as amphetamines, cocaine and modafinil. Since psychoactive substance abuse often occurs within a scenario of sleep deficit, the purpose of this investigation was to compare the sleep patterns of rats challenged with cocaine (7 mg/kg, ip), methamphetamine (7 mg/kg, ip), or modafinil (100 mg/kg, ip) subsequent to paradoxical sleep deprivation (PSD) for 96 h. Our results show that, immediately after 96 h of PSD, rats (10 per group) that were injected with a psychostimulant presented lower percentages of paradoxical sleep compared to those injected with saline (P < 0.01). Regarding slow wave sleep (SWS), rats injected with psychostimulants after PSD presented a late rebound (on the second night subsequent to the injection) in the percentage of this phase of sleep when compared to PSD rats injected with saline (P < 0.05). In addition, the current study has produced evidence of the characteristic effect of each drug on sleep architecture. Home cage control rats injected with modafinil and methamphetamine showed a reduction in SWS compared with the saline group. Methamphetamine affected sleep patterns most, since it significantly reduced paradoxical sleep, SWS and sleep efficiency before and after PSD compared to control (P < 0.05). Cocaine was the psychostimulant causing the least changes in sleep pattern in relation to those observed after saline injection. Therefore, our results suggest that abuse of these psychostimulants in a PSD paradigm aggravates their impact on sleep patterns.

Economic and cultural correlates of cannabis use among mid-adolescents in 31 countries

AIMS

To examine cannabis use among mid-adolescents in 31 countries and associations with per-capita personal consumer expenditure (PCE), unemployment, peer factors and national rates of cannabis use in 1999. DESIGN, PARTICIPANTS AND MEASUREMENT: Nationally representative, self-report, classroom survey with 22 223 male and 24 900 female 15-year-olds. Country characteristics were derived from publicly available economic databases and previously conducted cross-national surveys on substance use.

FINDINGS

Cannabis use appears to be normative among mid-adolescents in North America and several countries in Europe. The life-time prevalence of cannabis use was 26% among males and 15% among females and was lowest for males and females in the former Yugoslav Republic (TFYR) of Macedonia: 2.5% and to 2.5%, respectively; and highest for males in Switzerland (49.1%) and in Greenland for females (47.0%). The highest prevalence of frequent cannabis use (more than 40 times in life-time) was seen in Canada for males (14.2%) and in the United States for females (5.5%). Overall, life-time prevalence and frequent use are associated with PCE, perceived availability of cannabis (peer culture) and the presence of communities of older cannabis users (drug climate).

CONCLUSIONS

As PCE increases, cannabis use may be expected to increase and gender differences decrease. Cross-national comparable policy measures should be developed and evaluated to examine which harm reduction strategies are most effective.

Cannabis use and misuse prevalence among people with psychosis

BACKGROUND

Increasing attention has been given by researchers to cannabis use in individuals with psychosis. As psychoses are relatively low-prevalence disorders, research has been mostly been restricted to small-scale studies of treatment samples. The reported prevalence estimates obtained from these studies vary widely.

AIMS

To provide prevalence estimates based on larger samples and to examine sources of variability in prevalence estimates across studies.

METHOD

Data from 53 studies of treatment samples and 5 epidemiological studies were analysed.

RESULTS

Based on treatment sample data, prevalence estimates were calculated for current use (23.0%), current misuse (11.3%), 12-month use (29.2%), 12-month misuse (18.8%), lifetime use (42.1%) and lifetime misuse (22.5%). Epidemiological studies consistently reported higher cannabis use and misuse prevalence in people with psychosis.

CONCLUSIONS

The factor most consistently associated with increased odds of cannabis prevalence was specificity of diagnosis. Factors such as consumption patterns and study design merit further consideration.

The nature, time course and severity of methamphetamine withdrawal

AIMS

To characterize the natural history of methamphetamine withdrawal during the first 3 weeks of abstinence.

DESIGN

Cross-sectional study with comparison group. Setting A substance use treatment facility in Chiang Mai Province, Thailand.

PARTICIPANTS

The sample comprised 21 in-patients undergoing treatment for methamphetamine dependence. Nine age- and sex-matched non-dependent individuals provided comparison data.

MEASUREMENTS

Instruments including: the Amphetamine Withdrawal Questionnaire, a modified version of the Cocaine Selective Severity Assessment, Clinical Global Impression scale and the St Mary's Hospital Sleep Questionnaire were completed daily for the first 3 weeks of abstinence.

FINDINGS

Methamphetamine withdrawal severity declined from a high initial peak within 24 hours of the last use of amphetamines reducing to near control levels by the end of the first week of abstinence (the acute phase). The acute phase of amphetamine withdrawal was characterized by increased sleeping and eating, a cluster of depression-related symptoms and less severely, anxiety and craving-related symptoms. Following the acute withdrawal phase most withdrawal symptoms remained stable and at low levels for the remaining 2 weeks of abstinence.

CONCLUSIONS

This study has provided evidence of a methamphetamine withdrawal syndrome that can be categorized into two phases, the acute phase lasting 7-10 days during which overall symptom severity declined in a linear pattern from a high initial peak, and a subacute phase lasting at least a further 2 weeks.

Being stoned: a review of self-reported cannabis effects

Although there has been considerable research into the adverse effects of cannabis, less attention has been directed toward subjective effects that may be associated with ongoing cannabis use. Examination of self-reported cannabis effects is an important issue in understanding the widespread use of cannabis. While reviews have identified euphoria as a primary factor in maintaining cannabis use, relaxation is the effect reported most commonly in naturalistic studies of cannabis users, irrespective of the method used. Self-reported effects in 12 naturalistic and 18 laboratory studies were compared. Regardless of methodology there was considerable variation in the effects experienced. Variation has been reported in terms of opposite effects being experienced by different individuals, variation of effects by individuals within a single occasion and between occasions of use. Factors that might explain this variation are outlined. Limitations of the available literature and suggested directions for future research are discussed. [Green B, Kavanagh D, Young R. Being stoned: a review of self-reported cannabis effects.