The focus of the current investigation is to examine the temporal relationship of gambling onset and alcohol, tobacco, and cannabis initiation in adolescents and young adults (M age = 20.3 years) by examining the prevalence and pattern of onset for each substance and gambling pairing and the associated risk between gambling and each substance use. Data were drawn from the multiwave Missouri Family Study (n = 1,349) of African American (AA; n = 450) and White families (n = 317) enriched for risk for alcohol use disorder and includes those who were assessed for gambling behaviors and problems: AA (360 males, 390 females) and White (287 males, 312 females). Findings indicated racial differences in the overall prevalence of gambling behaviors and substance use as well as patterns of initiation-particularly within gambling/alcohol and gambling/tobacco for males. Survival models revealed some similarities as well as differences across race and gender groups in associations of gambling with initiation of substances, as well as substances with initiation of gambling. Alcohol use (AA males only) and cannabis use (AA males and White females) elevated the hazards of initiating gambling. In contrast, gambling significantly elevated the hazards of initiation alcohol across 3 of 4 groups and of cannabis use in AA males only. The results highlight some overlapping as well as distinct risk factors for both gambling and substance use initiation in this cohort enriched for vulnerability to alcohol use disorder (AUD). These findings have implications for integrating gambling prevention into existing substance use prevention and intervention efforts-particularly but not exclusively for young AA males.

Bakgrund: Både cannabisbruk och depression ökar bland ungdomar i Sverige. För att kunna förebygga och behandla krävs att inom socialt arbete ha en förståelse för varför ungdomar påbörjar ett cannabisbruk och/eller drabbas av depression. Syfte: Syftet med denna studie är att undersöka om det finns en relation mellan cannabisbruk och depression bland ungdomar samt i vilken riktning relationen går. Metod: Undersökningen görs genom en litteraturöversikt där tio artiklar i ämnet har studerats och sammanställts. Resultat: Resultatet visar viss evidens för en koppling mellan cannabisbruk och depression. Diskussion: Relationen påverkas av flera olika riskfaktorer som i sig påverkas av ungdomarnas bakgrund. Resultatet går dock inte att fullt ut generaliseras till Sverige då deltagarna i studierna som sammanställts är från andra länder och några av dem även från andra kontinenter. / Background: Cannabis use and depression are increasing among youth in Sweden. To be able to prevent and treat it is important to understand why young people use cannabis and also why young people get depressed.  Aim: The aim in this study is to examine if there is an association between cannabis use and depression among youth, and to examine in what direction the association goes.  Method: This study is a review where ten articles have been summarized and analyzed.   Result: The result shows us some evidence for an association between cannabis use and depression. Discussion: The result shows us that the relationship between cannabis use and depression is affected by multiple risk factors. The result can not be generalized for Swedish youth, due to the fact that the studies examined were from other countries than Sweden and some of them even other continents.

No description available.

Renewed interest in hemp (Cannabis sativa L.) for cannabinoid production has highlighted critical knowledge gaps for growers. The impacts of weed interference on hemp yield are largely unstudied despite causing serious economic losses in most cropping systems. Furthermore, understanding factors determining cannabinoid content of hemp will be crucial for effective production. To evaluate the effects of weed competition on hemp yield and cannabinoid content, hemp growing in plasticulture was subjected to competition from 5, 3, 1, or 0 waterhemp (Amaranthus tuberculatus (Moq.) Sauer) plants. Hemp biomass and cannabinoid content were not significantly affected by weed competition. Yields in weedy and weed-free treatments were generally comparable, although unexpectedly high variation limited the ability to detect subtle differences between treatments. Waterhemp biomass was significantly reduced by competition from hemp in comparison to hemp-free controls. Suppression of weed growth by hemp and lack of significant yield loss from weeds suggests that hemp can be highly competitive and grown successfully without herbicides in certain circumstances. Abundance and documented phytotoxicity of hemp secondary metabolites suggest a potential for allelopathic activity. While incorporated hemp residue was not more effective than a maize control at reducing plant growth, hemp residue and extracts effectively inhibit seed germination. A laboratory assay showed that crude extracts of hemp can reduce the germination of a Brassica napus L., a bioindicator. Furthermore, a greenhouse experiment showed that small amounts of hemp residue on the soil surface can effectively reduce and delay the germination of waterhemp. Together, these results show that hemp residue has the potential to be incorporated with a practice such as chaff-lining for enhanced control of germinating weed seeds.

Post-traumatic stress disorder is a disorder characterized by an inability to extinguish traumatic memories and heightened reactivity to emotional stimuli. Due to the heightened resistance of traumatic memories to extinction, treatment for PTSD has been challenging and is limited to behavioral therapies targeted at reducing responsivity to threatening stimuli. Currently there are no standard pharmacological interventions that are specific to PTSD; rather, drugs used appear to target symptoms of some of the co-morbid conditions, such as anxiety (e.g. benzodiazepines) or depression (antidepressants) - which may also affect fear-memory. In this thesis, we explore the effects of natural health products (NHPs) including naturally occurring peptides and some medical botanicals on fear memory in order to explore the efficacy of natural products as potential pharmacological targets for fear-based disorders. Fear-conditioning has been used effectively in both rodents and humans to study fear-learning. Fear-conditioning is a learning paradigm during which an unconditioned aversive stimulus (such as foot shock) is paired with a neutral stimulus (such as light or tone), such that the neutral stimulus becomes associated with aversion. Fear-learning has several well-characterized stages, including acquisition, consolidation, reconsolidation, expression, and extinction that can be manipulated in order to study the pharmacological action(s) on the attenuation of learned-fear. Blockade of reconsolidation, the state during which formed memories are briefly rendered susceptible to change following recall, may provide a window of opportunity to pharmacologically diminish learned fear. In Chapter 1 of the thesis, we discuss fear-conditioning as a pre-clinical model of PTSD to explore the effects of novel pharmacological treatments on the reconsolidation process in rodents. We ultimately hope to provide a framework for translational work in humans for attenuating conditioned responses to trauma-related stimuli among humans with PTSD. In Chapter 2, we present evidence that systemic administration of gastrin-releasing peptide attenuates the reconsolidation of conditioned fear in rodents. Similarly, in chapter 3, we explore the effects of Δ9-Tetrahydrocannabinol (THC) and Cannabidiol (CBD) on the reconsolidation of learned-fear, and provide evidence that cannabinoid molecules may similarly prove effective at blocking the reconsolidation of conditioned fear memories. In chapter 4, we present evidence demonstrating that extracts of medical botanical Souroubea sympetala and its components may similarly block reconsolidation of conditioned fear-memory, and also exert more general anxiolytic-like activity in the elevated plus maze paradigm. Finally, in chapter 5 a general discussion considers the relative therapeutic potential for future human clinical trials of each of the three tested groups of compounds.

Les dépendances à l'alcool, au tabac ou au cannabis sont des affections fréquentes, aux conséquences psychologiques, sociales et physiques sévères. Ces addictions comportent des facteurs socioculturels, psychologiques et biologiques. Leur clinique est également complexe, suggérant une importante hétérogénéité phénotypique et génétique. Les études d'agrégation familiale et de jumeaux ont montré une forte héritabilité de des addictions (entre 30 et 60%). Toutefois, si de nombreuses études ont suggéré l'association de certains variants génétiques avec telle ou telle affection, peu de gènes ont émergés comme clairement associés à une addiction dans les méta-analyses. L'hétérogénéité clinique et génétique de ces troubles pourrait être une des raisons à certains résultats négatifs. Dans ce travail, nous montrerons comment le démembrement phénotypique peut-être une approche nouvelle, permettant de mettre en évidence des phénotypes plus homogènes, et à plus fort support génétique. Un premier travail a porté sur les effets ressentis de la consommation de cannabis comme marqueur endophénotypique de dépendance au cannabis. Puis nous avons montré comment les comorbidités addictives ou l'âge de début constitue des phénotypes d'intérêt. Enfin, nous prendrons l'exemple d'un variant du gène codant pour le transporteur de la dopamine comme marqueur d'un phénotype intermédiaire de la dépendance à l'alcool. / The prevalence of tobacco, cannabis and alcohol dependences is considered as high in most countries, having devastating psychological, social and physical consequences. These disorders are supported by social, cultural, psychological and biological factors. Their clinical presentation is also complex, suggesting an important phenotypic and genetic heterogeneity. Family studies as well as twin studies suggest a high heritability of these disorders, ranging between 30% and 60%. However, very few genetic variants have been considered as formerly associated with addictions. The phenotypic and clinical heterogeneity could contribute at least in part to the lack of positive results in genetic studies. In the present dissertation, we will show how the disentanglement of these disorders constitute a new approach, allowing to discover novel phenotypes, more homogeneous and with a stronger genetic support. Our first work will examine the association between some variant along the dopamine transporter gene and complication associated with alcohol dependence, namely alcohol withdrawal seizures. Then we will show how the age at onset of alcohol dependence constitutes a novel phenotype of interest. We will also consider the association of tobacco smoking in alcohol dependent participants as an intermediate phenotype. Finally, we will consider the subjective effect of cannabis during the first use as a new endophenotype for cannabis dependence.

Indiana University-Purdue University Indianapolis (IUPUI) / Marijuana use is associated with many health risks, but is increasingly becoming more accepted; thus, use rates, as well as negative consequences, are growing. There is a need to better understand marijuana use behaviors so as to reduce its negative effects. The current study sought to test the viability of applying urgency theory to marijuana use behaviors by examining several pathways among negative urgency, marijuana-related attentional bias, coping motives, and marijuana use behaviors, across men and women. Participants (n=120, mean age= 26.61 years (SD=9.28), 50% women, 63% White/Caucasian) were recruited from the Indianapolis, IN area to participate in a cross-sectional study in which they completed self-report measures and a visual-probe computer task with eye-tracking following negative mood induction. Regression analyses and the PROCESS macro were used to examine study hypotheses. Several pathways were supported: Negative urgency was significantly associated with coping motives (β=0.24, p=0.01), coping motives were significantly associated with marijuana use behaviors (ΔR2= 0.55, p<0.01), and a serial mediation model was supported, in which the relationship between negative urgency and negative marijuana consequences was mediated by coping motives and then by marijuana use frequency (c’= 0.20, 95%CI= 0.06 to 0.50). Competing models were examined and not supported. There were no statistically significant pathways involving the attentional bias measures; although there was a pattern of small effect sizes demonstrating that attentional biases may relate to marijuana use behaviors in men and not in women. Findings from the current study serve as preliminary support for applying urgency theory to marijuana use behaviors. Overall, these findings suggest that negative urgency is a distal risk factor that influences the development of other, more proximal, predictors of marijuana use and negative marijuana consequences. Future studies should examine the time order of these relationships longitudinally to replicate and provide more confidence in the causal order of the model supported in the present study.

Indiana University-Purdue University Indianapolis (IUPUI) / Cannabis (and its main psychoactive component, THC) is one of the most widely-used drugs in the world, and recent expansion of its legal status has made it available in a variety of formulations and at a potency unrivaled in history. While its medicinal properties are gaining scientific support, so too is its potential to lead to abuse and dependence. Both initiation of cannabis use and frequent cannabis use are most prevalent in adolescence, and compared to adults, cannabis use by adolescents is associated with a greater likelihood of developing cannabis dependence and cannabis use disorder. Given the ethical limitations surrounding research that provides cannabis to non-users or non-adults, animal models of drug use can be valuable tools for the study of causes and consequences related to drug use, as well as allowing for investigating brain mechanisms underlying these factors. However, only recently have models in which animals reliably use cannabis (THC) at levels above its respective vehicle and at levels which produce consistent behavioral and physiological effects become available, and in no case has age-related differences in this use been examined. Thus, one goal of the current study was to directly compare the self-administration of edible THC (a route of administration used by humans and a formulation increasing in popularity) between adolescent and adult mice. Adolescents also appear to be differentially sensitive to various effects of several classes of drugs, and they have been shown to be less sensitive to the aversive effects of cannabis, thereby putting them at greater risk for elevated and continued use. Evidence also suggests that, in addition to the risk associated with adolescent cannabis use, having initial positive subjective experiences resulting from its use is a strong predictor of subsequent cannabis dependence. Thus, the second goal of the current study was to use the place conditioning paradigm to examine the reward- (or aversion-) inducing properties of THC in adolescent and adult C57BL/6J mice, using both the traditional experimenter-administered THC (via injection) as well as edible THC self-administration. Prior to initiating these THC studies, sensitivity of the place conditioning procedure to age-related differences in drug-induced reward was validated using cocaine, yielding locomotor stimulation in both ages and a decreased sensitivity to cocaine’s rewarding properties in adolescent mice. When provided limited access to edible THC dough in doses ranging from 0.0 to 6.0 mg/kg, mice showed a dose-dependent reduction in consumption across access sessions, and this reduction was more rapid in adult mice at the highest doses, suggesting that adolescent mice might have been less sensitive to its aversive properties. These same mice, as well as a separate group of mice receiving injection (also 0.0 to 6.0 mg/kg THC), were given place conditioning sessions, alternating between THC dough and control dough or THC injection and vehicle injection, for 6 days per week and were tested once per week across a total of 3 weeks. Mice conditioned using edible THC showed a neutral response (neither reward nor aversion) at all doses. However, mice conditioned using injected THC showed a conditioned place aversion to the highest dose, which was more pronounced in adult mice. Interestingly, in mice self-administering edible THC, the dose of THC consumed was related to the outcome of place conditioning, such that a conditioned place preference was observed for adult mice which shifted their consumption of 3.0 mg/kg edible THC downward relative to those mice with full consumption of 3.0 mg/kg, and for adolescent mice which had the highest degree of consumption of 6.0 mg/kg edible THC relative to those mice with the lowest consumption of 6.0 mg/kg. Furthermore, initial place preference outcomes at the individual level at test 1 predicted subsequent doses of edible THC consumed, suggesting mice adjust their self-administration of edible THC based on the subjective experience it produces. Besides its impact in place conditioning, THC also had differential effects on body weight and locomotor activity based on age and route of administration. Collectively, this project demonstrates that adolescent mice are less sensitive to the hedonic properties of both cocaine and THC, and that differences in edible THC self-administration between ages, and between individuals within an age, are likely related the subjective experience of its rewarding and aversive properties.

No description available.

Chronic neuropathic pain is a leading cause of disability worldwide and is associated with immense economic burden. Of all chronic neuropathic pain conditions, chemotherapy-induced peripheral neuropathy (CIPN) persists as a monumental public health crisis, as it is the most common comorbidity among those receiving chemotherapy for cancer treatment. CIPN is unique compared to other forms of neuropathic pain in that it is severely dose-limiting, often leading to disruption or cessation of chemotherapeutic treatment and complicating an individual’s cancer prognosis. Current pharmacological treatments for combatting CIPN are widespread yet are all accompanied with the same hindrances – they are limited in therapeutic efficacy when administered chronically and are associated with severe risk for adverse effects. Therefore, there is a clear unmet need for novel pharmacotherapies for CIPN that achieve strong therapeutic efficacy while minimizing the susceptibility to adverse events.Here, we characterize the therapeutic efficacy and pharmacological mechanisms of a novel, plant-derived alkaloid mitragynine (MG), a constituent of the kratom plant (Mitragyna speciosa) in a mouse model of CIPN. Kratom products have emerged in the US in recent years as a popular form of self-treating pain, opioid withdrawal, and symptoms of anxiety and depression, but these intended uses are largely based on anecdotal reports in humans. MG possesses a unique, mixed pharmacological profile combining opioid, adrenergic, and serotonergic properties – resembling the pharmacology of current CIPN pharmacotherapies such as antidepressants. However, the relation of these pharmacological mechanisms of MG to the context of CIPN remain under characterized. Kratom products are also commonly used in combination with cannabis products, which are also used for self-treating pain, and play a significant role in palliative care for terminal cancer patients. Yet, interactions between kratom alkaloids and cannabinoid signaling have yet to be studied in the context of CIPN. Lastly, the basis of potential utility of individual kratom constituents such as MG on anxiety- and depression-like behaviors, which are heavily comorbid in individuals with CIPN, remain understudied. The present studies were conducted to explore the role of the kratom alkaloid MG on both pain and affective behaviors associated with CIPN, at the pharmacological, cellular, and molecular level. To accomplish this, we measured 1. Contributions of opioid and adrenergic signaling mechanisms to the therapeutic efficacy of MG in a mouse model of oxaliplatin-induced mechanical hypersensitivity using pharmacological inhibition. 2. Contributions of cannabinoid signaling to the therapeutic efficacy of MG in a mouse model of oxaliplatin-induced mechanical hypersensitivity and inflammatory pain using pharmacological and genetic approaches. 3. Effects of MG on affective behaviors associated with CIPN using mouse models of the tail-suspension test, elevated zero maze, and conditioned place preference. Overall, the findings from this dissertation support the hypothesis that MG displays therapeutic efficacy against nocifensive behavior of CIPN and pain-related affective behaviors. Opioid, adrenergic, and cannabinoid mechanisms all contribute to the effect of MG on oxaliplatin-induced mechanical hypersensitivity. MG is also capable of normalizing aberrant neurotrophic factor signaling associated with CIPN. Lastly, MG produces anxiolytic effects when repeatedly administered without developing a conditioned place preference, suggesting that it achieves therapeutic efficacy in a model of CIPN without risk of adverse events. / Biomedical Sciences