Influence Drug Use Research Articles

An investigation of economic interactions between social reinforcement and heroin or cocaine in rats.

The primary goal of the present study was to determine the economic relationship between heroin and social reinforcement in rats: are they substitutes, independents, or complements? In Experiment 1, one group of rats was given a budget of responses that they could allocate between heroin and social reinforcement offered at various combinations of prices. A second group chose between two levers that each resulted in social reinforcement at varying prices when pressed. There was no relationship between the relative allocation of responses between heroin and social reinforcement and changes in their relative prices, indicating that these reinforcers are best viewed as independents. In contrast, when choosing between two sources of social reinforcement, rats increased the allocation of behavior to the cheaper option, confirming that the method used here was sensitive to detecting substitution effects. In Experiment 2, the same method was used to compare one group that chose between heroin and social reinforcement with a second group that chose between cocaine and social reinforcement. The finding that heroin and social reinforcement were independents was replicated. Additionally, there was some evidence that cocaine and social reinforcement were substitutes, at least when the first few minutes of the session were excluded. These results add to our knowledge of how drug and nondrug reinforcers interact in choice situations in rats and may model factors that influence drug use in humans.

Overdose responses among rural people who use drugs: A multi-regional qualitative study

BackgroundEfforts to distribute naloxone have equipped more people with the ability to reverse opioid overdoses but people who use drugs are often reluctant to call 911 due to concerns for legal repercussions. Rural communities face unique challenges in reducing overdose deaths compared to urban communities, including limited access to harm reduction services as well as greater concerns about stigma and privacy.MethodsThe Rural Opioid Initiative was funded in 2017 to better understand the health-related harms associated with the opioid crisis in rural US communities and consists of eight studies spanning ten states and 65 counties. Each study conducted semi-structured qualitative interviews with people who use drugs to understand contextual factors influencing drug use and health behaviors. We analyzed qualitative data from seven studies with data available at the time of analysis to understand peer response to overdose.ResultsOf the 304 participants interviewed, 55% were men, 70% were white, 80% reported current injection drug use, and 60% reported methamphetamine use. Similar to what has been found in studies focused on urban settings, people who use drugs in rural communities use a range of strategies to reverse overdoses, including non-evidence-based approaches. Several reported that multiple doses of naloxone are needed to reverse overdose. Three themes emerged around the willingness to call 911, including (1) hesitancy to call 911 for fear of legal consequences, (2) negative perceptions or experiences with law enforcement officers, and (3) efforts to obtain medical intervention while avoiding identification/law enforcement involvement.ConclusionPeople who use drugs employ multiple strategies to attempt overdose reversal, including non-evidence-based approaches. Greater education about the most effective and least harmful strategies is needed. Reluctance to call 911 is rooted in concerns about potential legal consequences as well as perceptions about law enforcement officers, which may be heightened in rural communities where people who use drugs are more easily identified by law enforcement. People who use drugs will go to great strides to connect their peers to needed medical services, suggesting that comprehensive interventions to reduce interactions with law enforcement officers and eliminate legal consequences for reporting overdoses are critical.

A Prospective Study of Adverse Childhood Experiences and Illicit Drug Use in Adulthood

Previous research indicates that adverse childhood experiences (ACEs) increase the risk for illicit drug use. Yet, much of this research relies on retrospective ACE reports and does not consider the wide array of more proximal life experiences that may impact adults’ substance use. The present research used two waves of data from the longitudinal Toledo Adolescent Relationships Study (TARS) to examine the impact of ACEs reported during adolescence on illicit drug use frequency in adulthood (average age 32) among 930 (403 men and 527 women) respondents. Findings indicated that ACEs had a cumulative effect on adults’ illicit drug use. Each additional ACE increased drug use frequency by 0.087 units (p < 0.05). Biological sex (b = -0.446, p < 0.001), number of biological children (b = -0.155, p < 0.01), anxiety symptoms, (b = 0.071, p < 0.001), adolescent drug use (b = 0.166, p < 0.001), and residing with other substance-using individuals (b = 1.127, p < 0.001) were also significant correlates of illicit drug use in adulthood. Mediation analyses revealed that respondents’ anxiety symptoms and adolescent drug use mediated the total effect of ACEs on adults’ drug use frequency. Based on these results, it is argued that clinicians and others working with those who are at risk for or who are presently using illicit substances should consider how early life adversity influences drug use, both directly and indirectly via proximal risks.

“They either leave you or they get involved in it”: Familial factors influencing drug use amongst Appalachian people

West Virginia, the only state entirely in Appalachia, is considered the epicenter of the opioid crisis. Children raised in families affected by opioid use disorder can develop their own substance use disorder later in life. The continuing opioid crisis coupled with social and health disparities suggest families in West Virginia are vulnerable to generational cycles of substance misuse. This qualitative study uses content analysis to present emergent themes discerned from participant interviews on the opioid epidemic and impacts of a restrictive opioid prescribing law in West Virginia. Participants in this study described how using opioids has impacted their lives, their family, and community. They recognized drug use was embedded along familial groups and influenced by significant others such as partners or peers. Parents described how children were a strong motivator for recovery and how they felt remorse for exposing their children to their drug use. This study highlights the importance of community engagement, parental support, and early identification of vulnerable young people to lessen the intergenerational continuance of substance use.

Prevalence and Causes of Drug Abuse among Youth-Recipients of School-Based Drug Education Programs: A Mixed-Method Study

This study investigated the impact of school-based drug education programs on drug use behavior through examining the prevalence and causes of drug abuse and addiction among youth-recipients (16-30 years) of drug education (DE) programs in Nigeria. A concurrent embedded mixed-method design was adopted for the study and data were collected with a questionnaire and an interview schedule on drug use behaviors. Results showed that drug abuse prevalence ranged from 3.8% for cocaine to 23.7% for alcohol, with daily addiction levels ranging from 1.3% to 5.0%. Depression, peer pressure, and social/economic hardships cause drug abuse. Drug education and gender influence drug use behavior. Drug abusers possess health, social, legal, and moral knowledges about drug use, with youth drug-abusers redefining responsible use by promoting the notion of “civilized use”. The study concluded that mainstream curricular drug prevention programs have little impact on drug use behavior since its recipients still abuse drugs. Drug education research, policy, and practice implications of the findings were discussed.

Factors Influencing the Use and Demand of New Coronavirus Therapy Drugs Among the Adults During COVID-19 in China.

This alteration in the policy of COVID-19 resulted in widespread infections throughout China. Most people only need some antiviral drugs such as lopinavir/ritonavir or Chinese herbal preparations for treatment. In this context, the lack of drug knowledge and inadequate drug availability are evident. This study aims to explore the factors influencing drug use and demand during the COVID-19 epidemic. This study used quota sampling based on gender, age, and place of residence to perform a cross-sectional survey on a sample of 771 adults. The researchers used chi-square tests to understand differences in drug use and demand across characteristics, and binary logistic regression to analyse the influencing factors. The study revealed that 85.9% of the participants used drugs following the COVID-19 infection. Participants with college and above, (OR=2.49, 95% CI=1.27-4.88) annual personal income between 30,000 and 80,000CNY (OR=2.19, 95% CI=1.35-3.55) and over 80,000CNY (OR=1.96, 95% CI=1.05-3.66) were more knowledgeable about using drugs. Gender, (OR=0.69, 95% CI=0.50-0.95) age, (OR=2.11, 95% CI=1.15-3.88) residence, (OR=1.58, 95% CI=1.06-2.37) chronic disease conditions (OR=0.46, 95% CI=0.27-0.78) and infection symptoms (OR=0.60, 95% CI=0.38-0.93) as factors influencing the need for drug delivery services. (P<0.05). Research has revealed that a significant proportion of infected people in China chose drug treatment during COVID-19. Individuals with severe symptoms use more medication and require more drug delivery and storage. Low-education and low-income populations are lacking in drug knowledge, and older adults with underlying medical conditions are more likely to need drug delivery services. Therefore, governments should prioritize vulnerable groups when formulating drug policies and target drug literacy and guidance. In addition, it is recommended that a drug distribution system be set up within the community so that those in need can have quick and easy access to drugs.

A mixed methods study about health problems and drug use in Belgian prisons during 2021-2022

Abstract Negative effects of imprisonment on quality of health and drug use are well known. Although the interference between social- psychological- and physical aspects of health seem obvious, in many prison settings an overall approach with respect to drug use is lacking. A mixed methods study collected data during 2021-2022 in five Belgian prisons. People in prison were randomly invited for a quantitative survey about drug use, violence, social contacts, loneliness, anxiety, depression and sleep. The survey was carried out in 13 languages using tablets. In total, 280 responses were analysed. Next, respondents of the survey that used illicit drugs were invited for an in-depth interview about personal insights on support needs of drug use and social-, physical- and emotional well-being (N = 38). Besides, persons released less than 1 year ago and who used illicit drugs (N = 12) were interviewed. Drug use and symptoms of anxiety, depression, sleep problems, loneliness, suicidal attempts and violence are 2 to 8 times higher in prison compared to community. Drug use inside prison was more prevalent (p &amp;lt; 0.05) among people with a prison history. Respondents also mentioned the negative influence of drug use on physical, social and emotional health. Severe depression symptoms and the occurrence of suicide attempts were more reported among people who used drugs in prison in the past month. Although most respondents indicated having received visits during the past month, lack of social contacts and dependence on others were strongly present during the interviews. The results suggest that the prison context affects the interconnection of biopsychosocial health aspects as a whole to such an extent that the likelihood of drug use increases. This finding is essential to address the needs of people in prison in a more holistic way. Enlarging this scope in prison policy and more specific treatment initiatives enables increasing equity in care and will improve both security and health outcomes. Key messages • The results support an expansion of treatment initiatives that have been already implemented but in which the interconnection of the biopsychosocial health aspects with drug-use should be integrated. • This study supports the idea to develop a more holistic prison policy by adding drug use, physical, social and mental health to the main concern of security.

A qualitative study of chronic pain and opioid use: The impact of restrictive prescribing.

To explore the continuum of pain and addiction for patients with chronic pain (CP) who used opioids during a time of restrictive opioid prescribing in West Virginia. This qualitative descriptive study used a content analysis of semistructured interviews. Themes were identified through a reflective, iterative coding process. Consolidated criteria for reporting qualitative research guidelines were followed. West Virginia. Twenty people who used opioids to treat a CP condition, 10 pharmacists, 10 primary care providers, and 10 specialists. Semistructured interviews. To better understand the impact of restrictive prescribing measures on people who used opioids for CP. Patients initiated opioids for acute, painful conditions and described how long-term use led to physical dependence and, for some, opioid use disorder. Restrictive opioid prescribing laws led to care interruptions and decreased access and availability of prescribed opioid pain medication, driving some patients to seek illicit drugs. Economic considerations influenced drug use as the price of purchasing prescription opioids on the street went up, making heroin a cheaper alternative. Patients who transitioned to buprenorphine/naloxone as a treatment for pain or opioid use disorder viewed it as a positive change and a "life saver." Opioid use for CP is complex and multifaceted. The continuum of pain and opioid use disorder can begin with a prescription for acute pain and continue for the treatment of CP. Patients described how continued opioid use was not to "get high" but for pain control to improve their quality of life, continue to work, and be productive. For those who experience physical dependence on opioids, access to treatment is vital to recovery and pain management. Without individualized managed care, people confronted with a sudden interruption in prescription opioids may turn to illicit drugs to mitigate symptoms of opioid withdrawal and physical dependence.

Environmental cues can indirectly acquire cocaine-eliciting changes in Heart Rate: A pilot study of derived relational responding, the transfer of function among cocaine users.

Identifying the processes by which environmental stimuli can come to influence drug use is important for developing more efficacious interventions. This study investigated derived relational responding and the transfer of differential conditioned effects of environmental stimuli paired with "smoked" cocaine in accordance with the relations of symmetry, transitivity, and equivalence using Heart Rate as the measure of conditioning among 12 adults with significant histories of cocaine use. Match-to-sample (MTS) procedures were used to test for emergent relations among two four-member stimulus groupings. One member of a group was then paired with 25-mg of smoked cocaine and one member of the other group was paired with 0-mg of smoked cocaine. 10 participants completed the MTS protocol: 4 participants demonstrated two four-member equivalence classes, 3 participants demonstrated two three-member equivalence classes and 2 participants demonstrated symmetry only. One participant demonstrated no derived relations. Differential respondent elicited changes in HR was demonstrated in the presence of stimuli paired with smoked cocaine among 4 of the 6 participants completing the conditioning phase; all 4 of the participants demonstrated a bi-directional transfer of these functions in accordance with symmetry. Transfer was not reliably demonstrated in accordance with transitive or equivalence relations. The results suggest that drug respondent elicitation in the context of drug use may be a function of both direct conditioning and relational processes. These findings have implications for studying and understanding the processes by which stimuli in the natural ecology can set the occasion for cocaine use and developing cocaine use disorder.

Factors Affecting Drug Use in the Household Environment During the Covid-19 Pandemic

Background:Inappropriate use of drugs is a big problem all over the world. The COVID-19 pandemic causes people to be easily influenced by information circulating about drugs that are efficacious to ward off COVID-19 so that many people consume excess drugs to protect themselves from COVID-19. The COVID-19 pandemic has also caused people to take health supplements to protect themselves from COVID-19.Objective:The purpose of this study was to determine the factors that influence drug use during the COVID pandemic.Methods:This research was an observational study with a cross sectional design. Sample was 115 respondents chosen by purposive sampling. Bivariate statistical test used was chi-square and multivariate test used was binary logistic regression. Results:Bivariate analysis result showed that age and distance from health care service did not significantly affect the drug use (p value &gt; 0,05). Education, occupation, income, knowledge were significantly influence the drug use (p value &lt; 0,05). In the multivariate analysis, the OR for education was 4,807, OR for occupation was 4,612, OR for income was 0.146. OR for knowledge 3,400.Conclusion:It can be concluded that the factors that significantly affect the use of drugs in the household environment of the Kota Sub-District Kudus Regency during the COVID-19 pandemic are occupation, education, income and knowledge

Health Outcomes by Neighborhood (HON): Effects of Neighborhood, Social Instability, and Health Factors on 12-Month Trajectories of Substance-Use Disorder Symptoms

Background Previous studies have shown that environment and health can influence drug use trajectories and the effects of substance use disorder (SUD) treatments. We hypothesized that trajectories of drug use-related problems, based on changes in DSM-5 symptoms, would vary by type(s) of drugs used, health factors, and neighborhood characteristics. Methods We assessed mental and physical health, stress, social instability, neighborhood characteristics (disorderliness and home value), and DSM-5 symptom counts at two study visits, 12 months apart, in a community sample (baseline N = 735) in Baltimore, MD. Three prominent categories of drug-use trajectory were identified with K-means cluster analysis of symptom counts: Persistent (4 or more symptoms at both visits or at Visit 2), Improved (decrease from 4 or more symptoms at Visit 1 to 3 or fewer symptoms at Visit 2), and Low-Stable (3 or fewer symptoms at both visits). Baseline health and neighborhood measures were tested as predictors of trajectory in mediation and moderation models. Results Among people with current opioid- and/or stimulant-use, odds of an Improved trajectory were (1) decreased with neighborhood disorder and social instability, or (2) increased with home value and social instability. Odds of a Low-Stable trajectory were decreased by social instability and stress but increased in those who were older or self-identified as white. Conclusions Trajectories of drug use-related problems are influenced by sociodemographic variables, neighborhood factors, and health. Assessing DSM-5 symptom counts as an outcome measure may be valuable in monitoring or predicting long-term trajectories and treatment effectiveness.

Contextualizing drug use and pharmacological harm in the United States: a socio-historical overview

The purpose of this conceptual paper is to navigate through the socio-historical modulations in American tolerance for different psychoactive substances, and propose a theoretical synthesis formed by two vanguard philosophical doctrines, objectivism, and constructivism. Our approach is grounded on the analysis of social historical context and objective harms that have influenced drug use tolerance in the United States based on key historical events such as: heavy drinking at the dawn of nineteenth century, the establishment and repeal of prohibition, late nineteenth century opiate and cocaine tolerance followed by early twentieth century prohibition, post-prohibition drug concerns such as marijuana prohibition in the 1930s, heroin concerns and medical depressant use in the 1950s, poly-drug use in the 1960s, crack cocaine use in the 1980s, and finally modulations in tolerance for peyote use. Evidence supports the notion of drug harms reduction for the privileged, and criminalization of drug use by marginalized groups. Over long spans of history, however, more objectively harmful drugs are rejected, while drugs that can be used regularly without serous dysfunction are tolerated and normalized. We argue that a framework of social status and pharmacological harm can account for the vacillating policy responses that have emerged to different drugs at different times. Our approach informs the role of socio-cultural conflict in drug policy development and infuse the need for empirical research on the effect of socioeconomic positioning on attitudes of medicalization and legalization of marijuana and opioid policy in contemporary America.

Does drug use affect the efficacy of amisulpride, aripiprazole and olanzapine in patients with schizophrenia spectrum disorders? Results from a pragmatic, randomised study

ObjectivesDrug use is prevalent in patients with schizophrenia spectrum disorders (SSD) but there is limited knowledge about the influence of drug use on the effectiveness of antipsychotic medication. This secondary explorative study compared the effectiveness of three antipsychotics in patients with SSD, with and without drug use. MethodsThe BeSt InTro multi-centre, head to head, rater-blinded randomised study compared amisulpride, aripiprazole and olanzapine over a 1-year follow-up period. All patients (n = 144) were aged ≥18 years and met the ICD-10 criteria for SSD (F20–29). Clinical symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS). The primary outcome was reduction of a PANSS positive subscale score. ResultsAt baseline, 38% of all patients reported drug use in the last 6 months before inclusion, with cannabis as the main drug (85%), followed by amphetamine-type stimulants (45%), sedatives (26%), hallucinogens (19%), cocaine (13%), opiates (4%), GHB (4%), solvents (4%), analgesics (4%) and anabolic steroids (2%). The predominant pattern was the use of several drugs. There were no significant overall differences in the PANSS positive subscale score reduction for the three studied antipsychotics among patients either with or without drug use. In the drug use group, older patients treated with amisulpride showed a greater PANSS positive subscale score reduction during the treatment period compared to younger patients. ConclusionThe current study showed that drug use does not appear to affect the overall effectiveness of amisulpride, aripiprazole and olanzapine in patients with SSD. However, amisulpride may be a particularly suitable choice for older patients with drug use.

Polypharmacy and precision medicine.

Precision medicine is an approach to maximise the effectiveness of disease treatment and prevention and minimise harm from medications by considering relevant demographic, clinical, genomic and environmental factors in making treatment decisions. Precision medicine is complex, even for decisions about single drugs for single diseases, as it requires expert consideration of multiple measurable factors that affect pharmacokinetics and pharmacodynamics, and many patient-specific variables. Given the increasing number of patients with multiple conditions and medications, there is a need to apply lessons learned from precision medicine in monotherapy and single disease management to optimise polypharmacy. However, precision medicine for optimisation of polypharmacy is particularly challenging because of the vast number of interacting factors that influence drug use and response. In this narrative review, we aim to provide and apply the latest research findings to achieve precision medicine in the context of polypharmacy. Specifically, this review aims to (1) summarise challenges in achieving precision medicine specific to polypharmacy; (2) synthesise the current approaches to precision medicine in polypharmacy; (3) provide a summary of the literature in the field of prediction of unknown drug-drug interactions (DDI) and (4) propose a novel approach to provide precision medicine for patients with polypharmacy. For our proposed model to be implemented in routine clinical practice, a comprehensive intervention bundle needs to be integrated into the electronic medical record using bioinformatic approaches on a wide range of data to predict the effects of polypharmacy regimens on an individual. In addition, clinicians need to be trained to interpret the results of data from sources including pharmacogenomic testing, DDI prediction and physiological-pharmacokinetic-pharmacodynamic modelling to inform their medication reviews. Future studies are needed to evaluate the efficacy of this model and to test generalisability so that it can be implemented at scale, aiming to improve outcomes in people with polypharmacy.

Do Control, Peers, and Permissive Attitudes to Drugs Influence Drug Use Frequency in a Gendered Way?

The dominant role of heroin in Chinese drug scenes has been gradually replaced by synthetic drugs since 2014. The gendered patterns of drug use have also changed with the transformation in drug consumption. Drawing upon survey data from 716 drug users detained in compulsory detoxification institutions, this study shows that permissive attitudes to drug use are a significant correlate of drug use frequency, and the correlation is much stronger among males than females. Neither self-control nor family attachment is significantly associated with drug use frequency. Drug-using peers are a constantly powerful correlate for drug use frequency among both males and females. Policy implications for improving treatment programs for detained drug users in compulsory detoxification institutions are discussed from a gender-specific perspective.

Drug use in patients with headache in the post-Covid period

Drug use is a risk factor for the chronification of primary headaches and the development of secondary headaches. Forms of persistent post COVID headache have been reported, which may be due in part to the headache attributed to COVID 19 but also to drug use. The aim of the study was to analyze post-COVID drug use in subjects with headaches and to compare with preinfection levels. Material and method: An online survey was done. Questionnaires were completed by subjects who had experienced COVID 19 infection and had a headache. The questionnaire was structured in 72 questions validated and approved by the institutional bioethics committee. Completion time - 20 min. The analysis of drug use was performed and the possible prediction factors were determined by simple multivariate regression. Results: The study included 140 subjects with a mean age of 37.44 ± 10.18 years, 88.6% being women. They reported average drug use for the treatment of pain (days / month) before COVID 19 infection = 4.15 ± 4,041 (days / month) vs. during COVID 19 infection = 9.80 ± 7.742 (days / month) vs post COVID period = 7.7 ± 8.243 (days /month) (½ p &lt;0.000, 1/3 p &lt;0.026). Multivariate regression analysis allowed the prediction of factors that influence drug use. Model 1 - R2 = 0.471, p = 0.031, F = 2.13, df = 15; Predictor 1 = previous drug use before COVID: B = 0.641, β = 0.408, t = 2.85, p = 0.017; Predictor 2 = post COVID headache: B = -2.33, β = -0.293, t = -2.09, p = 0.044; Predictor 3 = post COVID depression: B = - 4.00, β = -0.300, t = -2.09, p = 0.050. Model 3 - R2 = 0.204, p = 0.004, F = 6.26, df = 2, Predictor 1 = drug use before COVID: B = 0.595, β = 0.379, t = 2.9, p = 0.005, Predictor 2 = vertigo post COVID: B = 2.183, β = 0.319, t = 2.462, p = 0.017 Conclusion: Drug use in the post-COVID period is associated with several factors but predictive value showed drug use before infection, the nature of post-COVID headache, depression, and vertigo in the post-COVID period.

Factors Influencing Drug Use Information Received at Primary Healthcare Centre Pharmacies in Ghana.

Background:Health literacy addresses environmental, political, and social factors that determine health. Drug dispensers play a major role in educating patients on drug use to increase effective and efficient drug utilisation, thereby promoting positive healthcare outcomes. From the patients’ perspective, this study examined the communication quality between patients and drug dispensers at primary healthcare centres in the Cape Coast Metropolis of Ghana.Method:We conveniently surveyed 269 patients seeking health care at primary healthcare facilities using a researcher-constructed 13-item instrument. In SPSS version 21 software, we analysed the data using percentages, chi-square analysis, and logistic regression.Results:Almost half of the participants (n = 132) reported low health literacy, with 81% (n = 218) reporting that drug side effects were not discussed with them at the pharmacies. The findings further indicated that health literacy and educational level predicted general communication quality between participants and drug dispensers; participants with secondary education were about 3 times more likely to report not being told of the side effects of prescribed drugs as compared with those who had completed only basic education.Conclusions:There is still a high level of low health literacy among patients seeking healthcare at primary healthcare centres and a very high percentage of patients did not receive any education on side effects of dispensed drugs. Drug use directives from dispensers at primary healthcare facilities can make a difference between any 2 patients.

Social Contact Reinforces Cocaine Self-Administration in Young Adult Male Rats: The Role of Social Reinforcement in Vulnerability to Drug Use.

Drug-using peers are recognized as a leading factor influencing drug use among adolescents and young adults. One mechanism by which peers influence drug use is by providing social reinforcement for using drugs. Social reinforcement may be provided in multiple ways, including by making social contact contingent on drug use (i.e., an individual must use drugs to gain/maintain access to a peer). The purpose of this study was to develop a preclinical model in which intravenous cocaine self-administration was positively reinforced by access to a social partner. Young adult male rats were trained to self-administer cocaine in operant conditioning chambers with a guillotine door that could be opened to an adjacent compartment housing either a social partner or a non-social stimulus. Once cocaine self-administration was established, the guillotine door was activated, and cocaine intake was reinforced by brief access to either a social (age- and sex-matched peer) or non-social (black-and-white athletic sock) stimulus. Contingent access to a social partner rapidly increased cocaine self-administration. Total cocaine intake was 2- to 3-fold greater in rats assigned to the social versus non-social condition across a 100-fold dose range. Cocaine intake rapidly increased when rats in the original non-social group were later provided with social partners, whereas cocaine intake resisted change and remained elevated when rats in the original social group had their partners removed. These data indicate that contingent access to a social partner increases drug intake and suggest that social reinforcement may represent a vulnerability factor that is particularly resistant to psychosocial interventions.

Control, Peer Association, and Permissive Attitudes to Drug Use: An Integrated Model Explaining Illicit Drug Use in China

Since 2014, synthetic drugs have replaced opioids to become the most popular illicit drugs in China. Objectives: To explain illicit drug use in contemporary China, this research develops an integrative theoretical model including control theories, differential association theory, and normalization theory. Methods: The study draws on the first-hand data collected from 716 drug users in four compulsory drug detoxification institutions in China. Results: Low self-control increases drug use frequency through the heightened association with drug-use friends and more permissive attitudes to drug use simultaneously. However, family attachment indirectly influences drug use frequency via more permissive attitudes to drug use but not drug-use friends. Conclusion & contribution: The results show that the influence of self-control and family attachment is fully mediated by drug-use friends and permissive attitudes to drug use. This study provides a detailed picture of the mechanism of how self- and social control influence drug use frequency and contributes to the larger body of scholarship integrating criminological theories to understand drug use behaviors in China. The implications of the findings for scientific and effective drug treatment programs are also discussed.

Ocular recognition databases and competitions: a survey

The use of the iris and periocular region as biometric traits has been extensively investigated, mainly due to the singularity of the iris features and the use of the periocular region when the image resolution is not sufficient to extract iris information. In addition to providing information about an individual's identity, features extracted from these traits can also be explored to obtain other information such as the individual's gender, the influence of drug use, the use of contact lenses, spoofing, among others. This work presents a survey of the databases created for ocular recognition, detailing their protocols and how their images were acquired. We also describe and discuss the most popular ocular recognition competitions (contests), highlighting the submitted algorithms that achieved the best results using only iris trait and also fusing iris and periocular region information. Finally, we describe some relevant works applying deep learning techniques to ocular recognition and point out new challenges and future directions. Considering that there are a large number of ocular databases, and each one is usually designed for a specific problem, we believe this survey can provide a broad overview of the challenges in ocular biometrics.