Addiction最新文献

Aims: To test whether the total consumption model and its extension, the theory of collectivity, apply to adolescent cannabis use. We estimated: (1) whether the distribution of cannabis use frequency was stable over time; (2) whether changes in average cannabis use were mirrored across consumption quantiles; and (3) whether higher average use corresponds with a higher prevalence of high-frequency users.

Design: Repeated cross-sectional study based on annual surveys. We analyzed trends in cannabis use frequency across consumption percentiles using Lorenz curves and Gini coefficients to assess distributional stability. We used ordinary least squares (OLS) regression to estimate the elasticities between overall mean frequency of use and mean frequency of use for five quantiles ranging from P25 to P95. The association between average use and the prevalence of high-frequency users was examined graphically and parametrically.

Setting: Sweden.

Participants: Ninth-grade students (aged 15-16) surveyed annually between 1990 and 2023 (excluding 2013), with a total of 180 059 respondents, and 2nd-year high school students (aged 17-18) surveyed annually between 2004 and 2023 (excluding 2013 and 2020), totaling 80 925 respondents. Our analyses were limited to individuals who reported cannabis use, resulting in analytical samples of 10 139 9th-grade students and 11 160 2nd-year high school students.

Measurement: Frequency of cannabis use was measured by a question on how many occasions the respondent has used hashish or marijuana. The seven response alternatives ranged from 0 to 50 times or more.

Findings: Mean frequency of cannabis use fluctuated statistically significantly across survey years among 9th-grade students (F-test = 7.647, P < 0.001) and marginally among 2nd-year students (F-test = 1.550, P = 0.068). Notwithstanding this variation in mean use, the distribution of frequency of cannabis use remained stable: Lorenz curves were consistent across years, and Gini coefficients showed no significant changes. Mean frequency in all five quantiles (25th-95th) were positively and statistically significantly associated with overall mean frequency, suggesting synchronized changes across user groups; e.g. the elasticity for P50 was estimated at 0.914 (P < 0.001) in 9th grade. Increases in mean frequency use were associated with a higher prevalence of high-frequency users. Thus, an increase in average frequency of cannabis use by 1 percentage point was associated with a 1.794 (standard error = 0.065, P < 0.001) percentage point increase in high-frequency users in 9th grade.

Conclusions: Adolescent cannabis use in Sweden appears to conform to key predictions of the total consumption model and its extension, the theory of collectivity.

Background and aims: Illegal opioids create challenges for public health and safety. There is imperfect understanding of when use of illegally manufactured opioids increased. This paper examined data on self-reported year of first heroin use in the United States.

Design: Secondary analysis of general population survey data.

Setting: United States.

Participants: 1 708 720 across 38 surveys from 1979 to 2023.

Measurements: The U.S. National Survey on Drug Use and Health and its predecessors ask respondents about their year of first use for various substances. In any single survey, few report initiating heroin in a specific year, but combining multiple surveys improves precision, enabling the plotting of time trends. Those who initiate can be broken down by age and by whether they report having misused pain relievers before they first used heroin.

Findings: Self-reported heroin initiation appears to have been rare before the late 1960s, although data for those years are sparse. It rose sharply to a peak in 1972, fell by almost half, and remained stable from 1978 to 1994. It rose by about 75% in the late 1990s and a further 85% by the early 2010s. The proportion reporting misuse of prescription opioids before first using heroin increased from about one-third before 1990 to one-half by 2000 and 80% by 2010. The proportion who were over age 40 at the time of first heroin use increased from nearly 0 before 1990 to 10% in 2012 and about 40% in 2020-2021.

Conclusions: In the United States, heroin initiation that is self-reported to have occurred after 2000 differs in magnitude and character from that from the late 1970s through mid-1990s. Changes began before dates commonly associated with restrictions on opioid prescribing. This appears consistent with a view that "trading down" from prescription opioid misuse to consumption of illegally manufactured opioids did not only occur after implementation of policies to reduce opioid prescribing.

Background and aims: The global cannabidiol (CBD) market has expanded in recent years. Several studies suggest CBD use, whether for medical or recreational purposes, is on the rise; however, no systematic assessments of its prevalence have been conducted so far. This meta-analysis aimed to estimate the prevalence of CBD use in North America and Europe independently.

Methods: Searches were conducted in PubMed, PsycINFO and Web of Science on 25 March 2025. A total of 43 studies (48 distinct samples; n = 388 447; 57.52% female) from North America (k = 30; n = 353 088) and Europe (k = 13; n = 35 359) were included in the analyses. The prevalence was estimated at five time periods (i.e. lifetime, past 12 months, past 30 days, past 7 days and daily use) separately for each continent region. Differences in prevalence estimates by sex, year of data collection and sample type (i.e. clinical versus community) were examined. Publication bias was estimated using several indicators, and the methodological quality of the studies was appraised using the Joana Brigg's Institute (JBI) checklist.

Results: In preliminary analyses of heterogeneity there was evidence of differences in prevalence between North America and Europe across all time periods (P-value range: < 0.001-0.057). Consequently, the pooled prevalence estimates were calculated for both continental regions separately. In Europe, the pooled lifetime prevalence of CBD use was 12.8% [95% confidence interval (CI) = 0.06-0.25], 17.6% (95% CI = 0.11-0.28) in the past 12 months, 7.2% (95% CI = 0.02-0.21) in the past month, 4.3% (95% CI = 0.01-0.13) in the past week and 2.1% (95% CI = 0.01-0.08) daily. In North America, lifetime pooled estimates were 28.9% (95% CI = 0.2-0.39), 19.5% in the past 12 months (95% CI = 0.11-0.32), 12% in the past month (95% CI = 0.07-0.2), 10.5% in the past week (95% CI = 0.01-0.47) and 6.4% daily (95% CI = 0.03-0.13). Of the moderators tested, sample type statistically significantly influenced the meta-analyses. In Europe, clinical samples (25.6%) reported higher past-year prevalence of CBD use in comparison with community samples (11.6%), whereas in North America there was higher past-year use of CBD among community samples (26.1%) compared with clinical samples (4.1%).

Conclusions: Cannabidiol use appears to be more prevalent in North America compared with Europe.

Background and aims: Tissue-retained needles from intravenous drug use can cause rare but severe complications, ranging from local to systemic infections to needle embolization. Due to the limited evidence and the lack of epidemiological studies on the issue, we systematically reviewed the literature focusing on case reports and case series on the clinical presentations, diagnostic approaches, and management of tissue-retained needle fragments.

Methods: A systematic review of English-language case reports and case series was conducted (PROSPERO ID: CRD42024517020) on 15 November 2024, using PubMed and Scopus. Two authors performed the search independently and in duplicate following the PRISMA flow diagram. Case reports were included when the retained needles among people who inject drugs were confirmed by imaging, surgery or autopsy. Data on clinical characteristics, presentation, complications and outcomes were extracted by two reviewers and summarized descriptively.

Results: From 1479 citations, we included 46 publications reporting 52 cases [47 (90%) patients and 5 (9.6%) autopsy cases]. Patients were mostly young adults with a median age of 35.0 (range: 22-55) years and predominantly male [n = 37/52 (71%)]. No deaths were reported among the patients presenting with needle fragments; in the autopsy cases, the needles were incidental findings and not the cause of death. Although injection sites were not systematically imaged in all cases, nearly one third [n = 15/52 (29%)] of cases involved multiple retained needles. Needles migrated via circulation were most often found in the heart [n = 23/52 (44%)] or the lungs [n = 13/52 (25%)]. One fifth [10/47 (21%)] of the patients received antibiotics without needle retrieval, and in 18/47 patients (38%) the needle was surgically removed.

Conclusions: Retained needle fragments among people who inject drugs are found in a range of anatomical sites, are often multiple, are not associated with fatal outcomes and are often incidental findings in autopsies. Management varies substantially as some patients receive antibiotics alone while some have needles removed surgically.

Background and aims: By assessing neuroaffective response to motivationally relevant cues before a quit attempt, we have shown that smokers who attribute greater incentive salience to cigarette-related cues than non-cigarette-related rewards (Sign-trackers, ST) benefit more from varenicline compared with smokers with the opposite neuroaffective reactivity profile (Goal-trackers, GT). This proof-of-concept trial aimed to extend this work by testing whether the efficacy of varenicline relative to nicotine replacement treatment differs across the two neuroaffective reactivity profiles.

Design: A 2-group, double-blind, randomized controlled clinical trial with stratification on ST versus GT classification (based on baseline-assessed neuroaffective reactivity profiles) for adults seeking to quit smoking using varenicline or nicotine replacement therapy (NRT).

Setting: Hospital-based outpatient clinic specializing in smoking cessation treatment, located in Houston, Texas, USA.

Participants: 158 community volunteers (78 randomized to varenicline and 80 to NRT): 18-75 years of age, smoking 5 or more cigarettes/day and without severe comorbid psychiatric disorders, uncontrolled medical illnesses or contraindications for pharmacotherapy.

Interventions and comparators: Twelve weeks of varenicline or NRT combined with brief cessation counseling.

Measurements: Primary outcome: continuous smoking abstinence over the last 4 weeks of treatment.

Secondary outcomes: continuous abstinence at 3- and 6-month follow-ups.

Findings: Using a Bayesian approach, we estimated the probability that an interaction between treatment and neuroaffective profile exists. We pre-specified a probability above 80% as evidence for an interaction. Logistic regression indicated a 92.7% probability that an interaction between treatment and neuroaffective profile exists, exceeding the pre-specified threshold. Individuals with the ST profile responded better to varenicline than to NRT. At the end of treatment, the ST group showed a 35% Absolute Risk Difference (ARD) favoring varenicline over NRT (absolute cessation rates: 47% and 11%, respectively). In contrast, among individuals with the GT profile, the benefit of varenicline was smaller, with an ARD of 13% (absolute cessation rates of 29% for varenicline and 17% for NRT). The varenicline advantage for the ST group persisted at 3- and 6-month follow-ups.

Conclusions: Smokers seeking to quit who attribute greater incentive salience to cigarette-related cues than non-cigarette-related rewards benefit more from varenicline than from nicotine replacement therapy. These findings support using neuroaffective biomarkers to inform personalized smoking cessation interventions.

Background: For decades knowledge about the etiology, epidemiology, neurobiology, typology, and treatment of addiction in various populations has been well documented and widely disseminated. In more recent years, there has been a growing interest in investigating the prevalence, multiple pathways, and mechanisms that facilitate sustained remission and long-term stable recovery. Such an endeavor is predicated on the belief that discovery of not just more effective short-term stabilization and addiction treatment protocols, but also how people achieve long-term recovery will help ameliorate current addiction crises. Such experiential knowledge could inspire and inform the testing of new service strategies to meet the dynamic recovery needs of diverse populations-services that could be coordinated with, or supplant, existing ones toward the goals of engaging affected individuals and families earlier and better supporting them across the long-term stages of recovery.

Argument/analysis: The "why", "what" and "how", involved in creating and pursuing a recovery research agenda is described, with detailed attention given to twelve significant research dimensions that promise to enhance understanding of the multiple recovery pathways and mechanisms and thereby improve the precision, nature, timing, and scope of services. The article also describes how best to engage with recovery communities cross-culturally to obtain the most accurate, informative, and beneficial results.

Conclusions: A new science of addiction recovery promises to reinvigorate and vitally inform clinical and public health efforts in ameliorating endemic harms related to addiction.

Aims: To identify: (i) availability of nitazenes for purchase on international cryptomarkets and surface web shops, (ii) country of origin and country of destination of advertised products and (iii) types and forms of nitazenes available. We also identified shifts in market characteristics over time where possible.

Methods: Observational study of cryptomarkets and surface web marketplaces selling drugs and specifically nitazenes. Data comprised: (i) all drug listings on 34 cryptomarkets, collected twice monthly from October 2021 to September 2024, and from which nitazene listings were identified and (ii) all nitazene listings on 10 surface web shops, identified in April 2024 via search query on purchasing nitazenes in Australia on a common search engine. The former were analysed using Joinpoint regression; the latter descriptively.

Results: While nitazene listings comprised a small proportion of total drug listings across the cryptomarkets (0.16%), the proportion of nitazene listings had a small and fluctuating increase over the 3 years [average monthly percent change (MPC) = 1.7%; 95% confidence interval (CI) = 0.4%, 2.4%]. Overall, 78.9% of listings were reported as available for delivery to Australia, decreasing from 90.4% in October 2022 to 67.7% in September 2024 (MPC = -2.1%; 95% CI = -2.8%, -1.6%). The proportion reported as originating from Asia decreased from August 2023 (52.8%) to September 2024 (12.1%) (MPC = -11.7%; 95% CI = -16.3%, -8.9%), while listings originating from North America increased from April 2023 (19.3%) to September 2024 (82.8%) (MPC = 9.0%; 95% CI = 7.3%, 11.2%). Isotonitazene, protonitazene and metonitazene were most frequently identified, with proportion of isotonitazene and protonitazene listings increasing over the 3 years (average MPC = 2.1%; 95% CI = 1.5%, 2.8% and average MPC = 4.1%; 95% CI = 2.8%, 5.4%) and metonitazene declining (average MPC = -3.5%; 95% CI = -4.2%, -2.7%). Powder was the predominant form (87.2%), although the proportion of pills statistically significantly increased between October 2021 (0.0%) and September 2024 (20.2%) (MPC = 11.8%; 95% CI = 7.7%, 16.5%). Seven out of 10 surface web shops sold nitazenes for Australian delivery. Ten types of nitazene were identified on surface web shops. Powder was also the main form listed, followed by nasal sprays.

Conclusions: From October 2021 to September 2024, nitazenes were listed across a range of cryptomarkets and surface web shops, with shifts in the types available and their reported country of origin. These market insights show the importance of ongoing digital trace monitoring and reinforce the need for comprehensive harm reduction strategies and strong public health risk communication frameworks.