This experiment examined the forage potential of hemp (Cannabis sativa) and kenaf (Hibiscus cannabinus). The objectives were to evaluate yield and forage nutritive value (i.e. NDF, ADF, ADL, IVTD, and CP) fluctuations over the course of a growing season based on planting date, morphological composition, and management. Three types of hemp (grain, fiber, and a dual- purpose type) and kenaf were planted on two dates and were sampled approximately every two weeks throughout the growing season at the University of Kentucky (UK) Research Farm in Lexington, KY. Subsamples were separated into morphological components (i.e. leaf, flowers, stem, core fiber, and bast fiber) while the remainder of the sample was ground for laboratory analysis. All samples were scanned in Foss 6500 NIRS and wet chemistry analytical methods were utilized on a subset of samples to develop equations to predict the nutritive value of the remaining samples. Significant interactions for forage type, planting date, and harvest time were observed for yield, % floral components, % bast, and ADL. Significant interactions occurred between planting date and harvest date as well as type and harvest date for NDF, ADF, digestibility, crude protein, % leaf, % core, and % stem. Overall, forage nutritive value declined with increased plant maturity. The later planting date reduced the vegetative growth period, resulting in reduced leaf content, yield, and forage nutritive value. The performance of kenaf in this study indicates that it may be a better alternative forage than hemp due to remaining vegetative longer and having superior nutritive value. Better selection and the development of new hemp varieties with different photoperiod requirements could lengthen the vegetative state and may result in yields and nutritive values that are more competitive with kenaf and other typical forages.

Cannabis use initiated during adolescence may precipitate lasting consequences on the brain and behavioral health of the individual. However, research on the risk factors for cannabis use during adolescence has been largely cross-sectional in design. Despite the few prospective studies, even less is known about the neurobiological predictors. This dissertation improves on the extant literature by leveraging a large longitudinal study to uncover the predictors of cannabis use in adolescent samples collected prior to exposure. All data were drawn from the IMAGEN study and contained a large sample of adolescents studied at age 14 (N=2,224), and followed up at age 16 and 19. Participants were richly characterized using psychosocial questionnaires, structural and functional MRI, and genetic measurements. Two hypothesis-driven studies focused on amygdala reactivity and two data-driven studies across the feature domains were completed to characterize cannabis use in adolescence. The first study was cross-sectional and identified bilateral amygdala hyperactivity to angry faces in a sample reporting cannabis use by age 14 (n=70). The second study determined this amygdala effect was predictive of cannabis use by studying a sample of cannabis-naïve participants at age 14 who then used cannabis by age 19 (n=525). A dose-response relationship was observed such that heavy cannabis users exhibited higher amygdala reactivity. Exploratory analyses suggested amygdala reactivity decreased from age 14 to 19 within the cannabis sample, although statistical significance was not found. In the third study, data-driven machine learning analyses predicted cannabis initiation by age 16 separately for males (n=207) and females (n=158) using data from all feature domains. These analyses identified a sparse set of shared psychosocial predictors, whereas the identified brain predictors exhibited sex- and drug-specificity. Additional analyses predicted initiation by age 19 and identified a sparse set of psychosocial predictors for females only (n=145). The final study improved on drug-specificity by performing differential prediction analyses between matched samples of participants who initiated cannabis+binge drinking vs. binge drinking only by age 16 (males n=178; females n=148). A sparse subset of psychosocial predictors identified in the third study was reproduced, and novel brain predictors were identified. Those analyses were unique as they compared two machine learning algorithms, namely regularized logistic regression and random forest analyses. These studies substantiated the use of both hypothesis- and data-driven prediction analyses applied to large longitudinal datasets. They also addressed common issues related to human addiction research by examining sex-differences and drug-specificity. Critically, these studies uncovered predictors of use in samples collected prior to cannabis-exposure. The identified predictors are therefore disentangled from consequences of use. Results from all studies inform etiological mechanisms influencing cannabis use in adolescence. These findings can also be used to stratify risk in vulnerable adolescents and inform targets for interventions designed to curb use.

For years statistical analysis has been applied to different areas of the natural and applied sciences to determine the degree of confidence that can be placed in research results. This work is a good example of how statistics can be applied to toxicology to enable conclusions and inferences to be made about important areas of interest such as the drugs and driving situation in New Zealand. Two thousand uninjured drivers (Study 1) who had provided an evidential blood alcohol sample, were also tested for cannabis, methamphetamine, benzodiazepines and morphine to determine the incidence of drug use by drinking drivers. To determine the proportion of drivers killed in car crashes who had used drugs and/or alcohol, two hundred and twenty nine fatally injured drivers (Study 2) were tested for alcohol, cannabis, methamphetamine, morphine, benzodiazepines and neutral and basic medicinal drugs that might have an effect on driving performance. Alcohol, cannabis and their combination were found to be the most prevalent drugs used by drivers. The analytical methodologies used were developed and validated by the Institute of Environmental Science and Research Ltd., where this work was carried out. These techniques involved liquid-liquid and liquid-solid extractions, immunoassays and chromatographic techniques for screening and confirmation assays. The statistical analysis of the results was done under the supervision of the Institute's biostatistician. An approach to cannabis culpability, intended to elucidate the role of this drug in car crashes, was applied to the Study 2 results. The number of samples collected during one year of research was not sufficient to enable statistically robust conclusions to be drawn. Cannabis use is illegal in New Zealand but drugs (different to alcohol) are not regularly tested at the roadside. This work as part of a cross-departmental project titled Drinking and drugged driver control: delineating the problem is expected to support the establishment of strategies designed to reduce the road toll and possibly include the screening of non-alcohol drugs in serious and fatally injured drivers.

Depuis les années 1980, les significations attribuées aux usages de drogues ont profondément changé. Cette transformation contextuelle imprègne le passage de la mesure de la toxicomanie à la description de pratiques diverses. Cette évolution correspond au glissement d'un paradigme opposant drogues licite et illicite à un modèle des addictions intégrant l'ensemble des substances mais distinguant les comportements d'usage. La quantification de ces pratiques a pu se faire grâce à la réalisation d'enquêtes en population générale. Les choix méthodologiques effectués en France sur ces enquêtes sont envisagés dans leur interaction avec les représentations des usages de drogues. Souvent critiquées pour leur côté réducteur par les partisans d'une perspective plus compréhensive, ces enquêtes peuvent toutefois s'avérer pertinentes et fiables grâce notamment à l'articulation des méthodes quantitatives et qualitatives. L'essor de telles études s'est concrétisé par une offre grandissante de chiffres qui ont pris une place importante dans le débat public, au risque parfois de conférer à l'argumentation l'apparence trompeuse d'une objectivité mécanisée et incontestable.

While neuropsychological deficits have been reported in healthy individuals who use cannabis, data in patients with multiple sclerosis (MS) are lacking. Given that MS is associated with cognitive deterioration, the aim of this study was to determine the cognitive effects of inhaled or ingested cannabis in this population. Fifty MS patients (25 cannabis users and 25 non-users) completed the Minimal Assessment of Cognitive Function in MS battery of neuropsychological tests. Cannabis users had significantly poorer performance on measures of information processing speed, executive functions, and visuospatial perception, and were twice as likely to be classified as globally cognitively impaired. Similar results were found after controlling for potential confounding variables. This study provides evidence that prolonged cannabis use in MS patients is associated with poorer performance on cognitive domains commonly affected in this population. The therapeutic benefits patients may derive from using cannabis should be weighed against the associated cognitive side-effects.

While neuropsychological deficits have been reported in healthy individuals who use cannabis, data in patients with multiple sclerosis (MS) are lacking. Given that MS is associated with cognitive deterioration, the aim of this study was to determine the cognitive effects of inhaled or ingested cannabis in this population. Fifty MS patients (25 cannabis users and 25 non-users) completed the Minimal Assessment of Cognitive Function in MS battery of neuropsychological tests. Cannabis users had significantly poorer performance on measures of information processing speed, executive functions, and visuospatial perception, and were twice as likely to be classified as globally cognitively impaired. Similar results were found after controlling for potential confounding variables. This study provides evidence that prolonged cannabis use in MS patients is associated with poorer performance on cognitive domains commonly affected in this population. The therapeutic benefits patients may derive from using cannabis should be weighed against the associated cognitive side-effects.

Bakgrund: Smärta och smärtbehandling är en viktig del i sjuksköterskans yrkesutövning. Det är därför viktigt att ha kunskap om olika behandlingsmetoder för att på ett individanpassat sätt främja en god omvårdnad. Cannabis har länge använts i medicinskt syfte bland annat för att hantera smärta. En adekvat smärtlindring är av betydelse för patientens livskvalitet. Syfte: Att beskriva hur patienters livskvalitet påverkas av att använda cannabispreparat som analgetika vid långvariga smärttillstånd. Metod: Litteraturstudie med systematiska sökningar valdes som metod. Sökningarna utfördes i databaserna PubMed, CINAHL och PsycInfo, även manuella sökningar genomfördes. Resultat: Resultatet är baserat på 21 vetenskapliga artiklar med olika ansatser. Patienter med olika smärttillstånd kan få en analgetisk effekt av cannabispreparat. Livskvalitet mätt inom områden som sömn, aptit, illamående och kräkning förbättrades hos patienter som använder cannabisbaserad medicin i syfte att lindra smärta. Ingen förbättring sågs inom området generell livskvalitet. Konklusion: Cannabisbaserad medicin kan användas som en behandlingsmetod hos patienter med långvariga smärttillstånd. Mer forskning är nödvändig för att avgöra om och i så fall hur cannabisbaserad medicin påverkar livskvaliteten. Som sjuksköterska är det viktigt att ha evidensbaserad kunskap inom ämnet för att kunna möta patienter med komplexa smärttillstånd. / Background: Pain and pain management is an important part of nursing. Therefore it is important to have knowledge about different treatment therapies to be able to perform an individualized health care. Cannabis has been used in medical purpose for a long time in intention to handle pain. An adequate pain treatment is vital for the patient’s quality of life. Purpose: To describe how quality of life is affected by using medical cannabis as analgesics by patients with chronic pain. Method: A literature study with systematic searches was chosen as a method. The search was made in the databases PubMed, CINHAL and PsycInfo and also a manual search was made. Result: The result is based on 21 scientific articles with different approaches. Patients who are suffering from different pain disorders can get an analgesic effect by using cannabis-based medicine. Quality of life measured in the domains sleep, appetite, nausea and vomiting improved when using cannabis-based medicine in purpose to relief pain. There were no improvements in the domain general quality of life. Conclusion: Cannabis-based medicine can be used as a treatment option by patients who are suffering from different pain disorders. There is a need for more research in this area to determine if cannabis-based medicine affects quality of life. As a nurse it is important to receive evidensbased knowledge within the area to be able to meet patients with complex pain disorders.

De nombreuses études ont montré que la fréquence de l'usage, de l'abus et de la dépendance au cannabis sont particulièrement élevés chez les patients atteints de schizophrénie, à tous les stades de leur évolution : lors des prodromes de la maladie, lors du 1er épisode psychotique et au cours de l'évolution. Les raisons de la fréquence de la comorbidité sont multifactorielles et comprennent les effets psychotomimétiques induits par la consommation de cannabis, certains traits de personnalité et une vulnérabilité familiale, dont nous avons étudié certains aspects. Nous avons retrouvé des scores de SNM plus élevés dans une population de patients non psychotiques, dépendants au cannabis que chez les sujets témoins, en particulier des scores de coordination motrice et d'intégration sensorielle. Nous avons retrouvé des niveaux d'impulsivité et de recherche de sensations plus élevés chez les patients atteints de schizophrénie avec abus/dépendance au cannabis par rapport aux patients simples usagers et aux patients abstinents. Nous avons évalué les caractéristiques des patients sensibles aux effets psychotomimétiques induits par le cannabis : ils avaient un âge de début du 1er épisode psychotique plus précoce (2 ans et demi) et des antécédents familiaux de troubles psychotiques plus fréquents par rapport aux patients non sensibles. Dans une étude réalisée dans un service universitaire au Maroc, nous avons retrouvé que le profil des conduites addictives chez les patients schizophrènes était différent de celui retrouvé dans les études antérieures en Europe ou en Amérique du Nord, suggérant que la disponibilité des drogues et le contexte socio-culturel ont aussi une influence.

Uppsatsen undersöker diskurser om cannabis och hur bilden av ungdomar och vuxna som använder drogen presenteras i tidningarna Aftonbladet, Dagens Nyheter, Expressen och Svenska Dagbladet under år 2012. Studien är en kvalitativ diskursanalys efter Norman Faircoughs tredimensionella metod. Intresset uppkom i och med den diskussion som internationellt växt fram under året. Länder som kulturellt och politiskt stått förebild för svensk utveckling i många frågor rapporterades revidera och omformulera den egna problembilden av cannabis. För en grundläggande förståelse av hur rapporteringen om narkotika sett ut i svensk dagspress har Daniel Törnqvists avhandling “När man talar om knark” legat till grund för arbetets utformning. De medieteoriska utgångspunkterna har varit moralpanik och skiftet från socialpolitik till kriminalpolitik som skett i pressen. Under det analyserade året återkom teman för hur rapporteringen ser ut, beträffande ungdom och narkotika centraliserar samhällets rädsla för den första att komma i kontakt med den senare. Medias förhållningssätt i frågan har tydliga likheter med hur pressen internationellt förhöll sig till subkulturer decennier tillbaka. Den cannabisanvändande kvinnan belyses likaså, tillskrivs en tydlig offerroll och är ur ansvarssynpunkt överskuggad av relationer med män. Mannen är ansvarig för kvinnans missbruk och i förlängningen hennes förfall, en bild som av media presenterats under flera årtionden. Ur vårt material har vi tyckt oss främst finna två diskursiva drag, låt gå och hårdare tag, varandras motsatser.

Notre recherche analyse le point de vue d'élèves du secondaire sur les activités déployées en prévention de l'usage du cannabis dans la perspective de l'approche de la réduction des méfaits. Elle explore leur opinion sur les activités en classe et les interventions individuelles dans une école secondaire de l'Ouest-de-I 'Île de Montréal. L'objectif de cette étude consiste à mettre à profit les acteurs concernés, soit les adolescent(e)s, dans leur appréciation des interventions réalisées à l'école. Nous désirons vérifier la pertinence de l'utilisation de l'approche de la réduction des méfaits auprès des adolescent(e)s à travers le propos de ces derniers. Notre recherche repose sur une approche qualitative. Des entrevues semi-dirigées ont été réalisées auprès de cinq jeunes de secondaire trois. L'analyse du matériel recueilli a permis de réaliser que les jeunes désirent recevoir une information juste et honnête dans le domaine de la toxicomanie, notamment à propos de l'usage des psychotropes. Ils sont capables de faire le lien entre les différents modes de consommation. Les interventions les ont amenés à réfléchir sur leur position face à l'usage du cannabis. Certains ont expérimenté la substance, d'autres sont demeurés abstinents. Quelques-uns ont même consommé régulièrement le cannabis pour diminuer leur usage par la suite. Les activités en classe utilisant l'approche de la réduction des méfaits ne semblent pas favoriser la banalisation du cannabis et de ses dérivés mais permettent au jeune de réfléchir et de construire son opinion personnelle en regard de la consommation. De plus, les jeunes acceptent la réglementation au Code de vie, mais ajoutent que son application devrait cibler davantage les jeunes consommateurs problématiques et susciter la réflexion sur la répression. Au terme de cette étude, nous recommandons la poursuite des activités en classe en précisant l'approche de la réduction des méfaits. Nous recommandons de plus que le protocole d'intervention actuellement en vigueur à l'école fasse l'objet d'ajustements. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Adolescence, Approche qualitative, Cannabis, Entrevue semi-dirigée, Milieu scolaire secondaire, Prévention primaire, Prévention secondaire, Réduction des méfaits, Toxicomanie.