This thesis comprises a review of studies on the diffusion of recommended guidelines on preventive practices and three papers evaluating the preventive practice patterns of general practitioners in Torino, Italy. / The first paper presents estimates of preventive practices and perceived effectiveness of preventive interventions. Patterns of practice were found to be consistently similar to those in other studies. / The second and third papers explore an array of determinants for ten primary and secondary preventive interventions. / An analysis of determinants indicates that complex patterns of behaviours are rather condition-specific, while the application of techniques is influenced to a varying extent by organizational and attitudinal factors.

An epidemic of hepatitis B occurring in a rural area of Nova Scotia in 1988 and 1989 was investigated. Illicit injectable drug use (IIDU) was the major determinant of transmission. The epidemic was the first highly visible indication of IIDU in Nova Scotia. A contact-tracing approach was used to identify the cohort of IIDUs. Of 186 IIDUs, 78 had serological evidence of hepatitis B infection. Using epidemiological criteria, it was determined that 57 of these formed a definite cluster of hepatitis B infections. Age, the total number of IIDU-contacts named and the number of hepatitis B seropositive IIDU-contacts named were identified as risk factors for hepatitis B infection. Six cases of delta hepatitis coinfection were found among the cluster cases, with a secondary attack rate estimated at seven percent. Risk-reduction and immunization strategies for the prevention of viral illnesses associated with IIDU were recommended.

The present investigation explored and compared the subjective responses of patients in the stable-phase of schizophrenia being treated with either olanzapine or risperidone. Several well-established, self-report inventories were used in this investigation, providing a means of assessing the impact of these medications from the perspective of the patient. The mean dosage of olanzapine (15.0mg) and risperidone (4.2mg) used in the present investigation were in line with treatment guidelines and standards of care. Findings include a highly knowledgeable sample of patients, who are satisfied with the information provided regarding their medication and treatment. Patients in both treatment groups were found to possess positive attitudes towards their medication, and a relatively high overall level of well-being and health-related quality of life. The majority of patients, in both treatment groups, expressed a high degree of satisfaction with various life domains, including their mental health services and their general health status. (Abstract shortened by UMI.)

The American Academy of Pediatrics recommends that children and adolescents with a family history of premature cardiovascular disease (CVD) and/or parental total cholesterol (TC) ≥6.2 mmol/L be screened for hypercholesterolemia. Questionnaires (from children and parents), clinical and blood sample data were collected in a provincially representative sample of 9-, 13-, and 16-year-olds (n = 2217) in Quebec to evaluate the usefulness of parental history (PH) of CVD and/or parental hypercholesterolemia to screen youth for raised low density lipoprotein cholesterol (LDL-C). Mean bias assessed by an external laboratory gold standard ranged from 1.0% to 2.1%, -0.4% to 5.1%, and -1.4% to 0.1% according to TC, triglyceride, and high density lipoprotein cholesterol tertiles. LDL-C was calculated using the Friedewald equation. Positive PH was defined as one/both biological parents diagnosed with a high cholesterol level, and/or taking cholesterol-lowering medication, and/or ever having had a heart attack, angina, stroke, cerebral vascular disease, peripheral vascular disease, and/or taking medication 'for the heart'. Performance statistics were calculated to determine the usefulness of PH in predicting borderline/high LDL-C (LDL-C ≥2.8 mmol/L) and high LDL-C (LDL-C ≥3.4 mmo1/L). 18.3% and 4.8% of subjects had borderline/high LDL-C and high LDL-C; positive predictive value (PPV) was 23.7% and 7.7%, respectively. Therefore PPVs were only marginally higher than the corresponding population prevalences and likelihood ratios were respectively 1.38 and 1.63: close to 1.00. In conclusion, PH offers little improvement over random screening.

There is growing consensus that health-related quality of life (HRQL) outcomes are important for the allocation of scarce medical resources and for facilitating clinical decision-making. However, because most instruments of HRQL are self-report measures inappropriate conclusions may be drawn from studies that assess changes in HRQL over time or between groups. If the individuals evaluating themselves experience a response shift (defined as changes in their internalized standard of evaluating their level of functioning, in their values, or in their conceptualization of the target construct), then measures taken over time or between groups are no longer comparable. To date, response shift has not been formally assessed in the stroke population, and only to a limited extent in the HRQL field. The global objective of this thesis was to examine how the experience of recovering from a stroke modifies people's perception of their health-related quality of life (HRQL), and the extent to which response shift occurs during the first six months post-stroke. / The first study used structural equation modeling for data from a prospective cohort to evaluate response shift by examining changes in a theoretical model of HRQL based on the measurement model of the Medical Outcome Study 36-Item Short Form Health Survey (SF-36). This study found no evidence of reconceptualization and changes in internal standards over time, but suggested that if response shift does occur with stroke it is likely to be mediated by the event itself and not the recovery process. Two subsequent studies evaluated response shift using the then test (a retrospective assessment of HRQL) and an individualized measure of HRQL. The data collection for these studies was incorporated into a randomized controlled trial. The results from the then test provided support for the occurrence of response shift among persons with stroke with no such effect in a control group. Changes on the individualized measure of HRQL showed that individuals with stroke experienced a reconceptualization and a change in values between 6 and 24-weeks post-stroke. A final comparison of the three techniques evaluated in this thesis provided the basis for proposed guidelines for future assessments of change in HRQL based on the comparative feasibility and validity of the methods. To date, there is evidence to show that individuals undergoing changes in physical health experience changes in internal standards of health and values. If response shift is not measured and accounted for, inappropriate conclusions regarding the impact of a disease such as stroke or the efficacy of a treatment intervention may go unnoticed.

Introduction. Research into medications for Alzheimer's disease (AD) is primarily conducted in drug trials, were efficacy is assessed by changes in score on established outcome measurement scales. However, physicians' and caregivers' perspectives on efficacy, along with their perspectives on other factors that may influence prescribing (e.g., adverse effects), remain largely unexplored. The objective of this thesis is to examine these perspectives to gain a broader understanding of the factors that can influence the use of medications in AD. / Methods. Two studies were conducted. The first involved all of the Province of Quebec's geriatricians, neurologists, and psychogeriatricians, as well as a random sample of Quebec's 8,115 general practitioners. The second study involved 375 caregivers who attended AD-related support groups. Questionnaires were used to collect data on the proportion of patients prescribed cholinesterase inhibitors (ChEIs), efficacy requirements for prescribing new medications, acceptance of adverse effects, physician-caregivers discussions about medications, and caregiver pressure on physicians to prescribe medications. / Results. Response rates were 35.4% (physicians) and 64.4% (caregivers). More stringent efficacy requirements on the part of physicians were negatively associated with prescribing ChEIs, although effect sizes were small and associations were not always statistically significant. More stringent efficacy requirements on the part of caregivers were negatively associated with prescribing in some instances (e.g., required improvements to patients' ability to eat, OR=0.74, 95% CI=0.61 to 0.89), but not in others (e.g., required improvements to patients' speech, OR=1.02, 95% CI=0.81 to 1.19). Caregivers' willingness to accept adverse effects was positively associated with prescribing ChEIs (odds ratios for 11 adverse effects ranged from 1.83 to 8.30); however, prescribing was not associated with physicians being the first to discuss the use of medications to treat AD (OR=2.37; 95% CI=0.90 to 6.24), nor was it associated with caregiver pressure on physicians to prescribe (OR=1.33; 95% CI=0.49 to 3.58). / Conclusion. This research is the first to show how physician and caregiver perspectives on issues such as efficacy and safety can affect the use of medications in AD.

Following a first episode of psychosis, many patients who are diagnosed with schizophrenia respond inadequately to or not at all to standard treatment. A better understanding of this heterogeneity can come from the identification of neurocognitive and neuroimaging markers related to remission. With the well known predictive value of short-term outcome for long-term trajectories, this project set out to identify: 1) neurocognitive and 2) structural & functional neural correlates of early remission in first-episode schizophrenia patients. All patients were treated at the Prevention and Early Intervention Program for Psychoses at the Douglas Mental Health University Institute. Early remission was defined as mild or less on 8 key symptoms and maintained for 6 months (from month 6 to month 12 after the start of treatment for this project) as per the Remission in Schizophrenia Working Group consensus definition (Andreasen et al. (2005). Am J Psychiatry, 162, 441-449); all subsequent analyses compared non-remitted and remitted patients. For the neurocognitive analysis, six cognitive domains (verbal memory, visual memory, working memory, speed of processing, reasoning & problem solving, and attention) were created from baseline neuropsychological data. Results revealed all patients displayed deficits across all domains with verbal memory performance significantly lower in non-remitted patients compared to remitted patients. The initial structural neuroimaging analysis looked for grey matter differences in whole-brain images utilizing a fully automated technique. Results identified lower parahippocampal grey matter concentration bilaterally in non-remitted patients compared to remitted patients. Post-hoc manual segmentation of the parahippocampus revealed the volumetric difference was limited to the parahippocampal cortex and not present in the entorhinal or perirhinal cortices. In the last structural analysis, the hippocampus and amygdala were manually segmented with the hippocampus subsequently divided into three subregions: the head, body, and tail. Results showed lower grey matter volume in the hippocampus tail in non-remitted patients compared to remitted patients. Finally, the functional analysis employed a behavioural memory task that allowed for three comparisons: encoding strategy, semantic relatedness, and subsequent memory effect. Results from the semantic relatedness comparison identified increased activity in the posterior cingulate/precuneus in non-remitted patients compared to remitted patients. An increase in activation in this structure has been related to memory deficits in schizophrenia. Altogether, increased activity in the posterior cingulate, reduced volume in the hippocampus tail and parahippocampal cortex (posterior regions), and the severe memory deficits identified in the non-remitted patients compared to the remitted patients, suggest abnormalities in a posterior memory network are present in patients that do not achieve remission. These results support the notion that neural integrity is clinically relevant in relation to the heterogeneity of outcome in schizophrenia. These markers of early remission could be pursued as potential areas-of-interest in developing newer treatments in hope of achieving a more favourable outcome for those who do not respond to treatment early. / Après un premier épisode de psychose, de nombreux patients souffrant de schizophrénie ne répondent pas adéquatement ou pas du tout aux traitements habituels. L'identification de marqueurs cognitifs et d'imagerie cérébrale liés à la rémission peut aider à mieux comprendre cette hétérogénéité. En utilisant la valeur prédictive de l'issue clinique à court terme sur les trajectoires à long terme, ce projet visait à identifier des corrélats 1) cognitifs et 2) neuronaux structurels et fonctionnels de la rémission chez des patients présentant un premier épisode de schizophrénie. Tous les patients étaient traités au programme d'évaluation, d'intervention et de prévention des psychoses de l'Institut Universitaire en Santé Mentale Douglas. La rémission précoce a été définie comme un niveau léger ou moindre sur 8 symptômes principaux maintenu pendant 6 mois (du mois 6 au mois 12 après le début du traitement pour ce projet), selon la définition consensuelle du Remission in Schizophrenia Working Group (Andreasen et al. (2005). Am J Psychiatry, 162, 441-449); toutes les analyses subséquentes ont comparé des patients en rémission et non-remis. Pour l'analyse touchant à la neurocognition, six domaines cognitifs (mémoire verbale, mémoire visuelle, mémoire de travail, vitesse de traitement, le raisonnement et la résolution de problèmes, et l'attention) ont été créés à partir des données neuropsychologiques obtenues à l'entrée au programme. Les résultats ont révélé que tous les patients ont des déficits dans tous les domaines mais la performance en mémoire verbale est significativement plus faible chez les patients non-remis par rapport aux patients en rémission. L'analyse initiale d'imagerie cérébrale structurelle a examiné les différences de matière grise dans le cerveau entier en utilisant une technique entièrement automatisée. Les résultats montrent une plus faible concentration de matière grise parahippocampique bilatéralement chez les patients non-remis par rapport aux patients en rémission. La segmentation manuelle post-hoc de la région parahippocampique a révélé que la différence volumétrique était limitée au cortex parahippocampique et n'incluait pas les cortex entorhinal ou périrhinal. En la dernière analyse structurelle, l'hippocampe et l'amygdale ont été segmentée manuellement avec l'hippocampe subdivisée en trois régions (la tête, le corps et la queue). Les résultats ont révélé un volume plus faible de matière grise dans la queue de l'hippocampe chez les patients non-remis par rapport aux patients en rémission. Enfin, nous avons utilisé une tâche de mémoire en imagerie cérébrale fonctionnelle qui a permis trois comparaisons: la stratégie d'encodage, la relation sémantique, et l'effet de mémoire subséquente. La comparaison pour la relation sémantique a montré une activité accrue dans le cortex cingulaire postérieur/précunéus chez les patients non-remis par rapport aux patients en rémission. Une augmentation de l'activation de cette structure a été associée à des atteintes de la mémoire chez les schizophrènes. Une activité accrue dans le cortex cingulaire postérieur, un volume plus faible dans la queue de l'hippocampe et dans le cortex parahippocampal (régions postérieures), et des déficits sévères de mémoire identifiés chez les patients non-remis par rapport aux patients en rémission suggèrent que des anomalies dans un réseau de mémoire postérieur sont présentes chez les patients qui n'atteignent pas la rémission. Ces résultats appuient la notion que l'intégrité neurologique joue un rôle important dans l'hétérogénéité de l'issue clinique en schizophrénie. Ces marqueurs de rémission précoce pourraient être considérés en tant que zones d'intérêt potentielles dans le développement de nouveaux traitements et ce, dans l'espoir de parvenir à une issue clinique plus favorable pour ceux qui ne répondent pas à un traitement précoce.

Youth suicide attempters are at high-risk for completing suicide. Many have untreated mental health problems and are not receiving services. Therefore, there is an urgent need to better understand potential influences associated with service use amongst this population. Spirituality and/or religion are potential cultural influences in all stages of youths' mental health service trajectories. This thesis explored youths' experiences of spirituality/religion as it relates to their help-seeking trajectories in the year prior to their suicide attempt. Fifteen youth (aged 14-18) who had made a suicide attempt(s) in the past 1 to 2 years were consecutively recruited through the Depressive Disorder Program of a psychiatric hospital and interviewed using open ended questions and one questionnaire. A mixed-methods design, including an adapted form of the psychological autopsy method, was used. Three themes emerged in the interviews. Religious community members acted as a bridge, step, or provider in relation to mental health services. Religious and spiritual discourses were encountered within services. Many youths reported different levels of spirituality and/or religious beliefs during the year prior to their suicide attempt. Spirituality and religion can have a role in youth suicide attempters' service trajectories. How this confers protection or challenges for each youth's trajectory needs to be clarified. Service providers need to be careful how they address these complex issues. Already, findings from the study in this thesis can inform policies in mental health services, suicide prevention and alert clinicians to suicidal youths' perspectives about spirituality and religion which may affect service utilization. / Les jeunes ayant fait une tentative de suicide sont à haut risque de s'enlever la vie par suicide. De nombreux jeunes ayant des problèmes de santé mentale ne sont pas traités pour leurs problèmes de santé mentale et ne reçoivent pas de services. Ainsi, il y a un besoin urgent de mieux comprendre les influences potentielles liées à l'utilisation de services parmi cette population. La spiritualité et/ou la religion sont des influences culturelles potentielles à tous les stades de la trajectoire de services en santé mentale des jeunes qui ont fait une tentative de suicide. Cette thèse a exploré les expériences des jeunes au niveau de la spiritualité/religion en lien avec leur trajectoire de recherche d'aide dans l'année précédant leur tentative de suicide. Quinze jeunes (âgés de 14 à 18 ans) ayant fait une tentative de suicide dans la dernière ou les deux dernières années ont été recrutés consécutivement via le Programme des Troubles Dépressifs d'un hôpital psychiatrique et ont été interviewés en utilisant des questions « ouvertes » et un questionnaire. Une approche méthodologique mixte, incluant une version adaptée de l'autopsie psychologique, a été utilisée. Trois thèmes sont ressortis des entrevues. Les membres des communautés religieuses ont permis soit de faire le pont vers les services en santé mentale, d'être une étape dans l'offre de services ou de donner les soins proprement dits. Les jeunes ont été en contact avec des discours religieux et spirituels à différents moments dans les services de santé usuels. Plusieurs jeunes ont rapporté différents niveaux de spiritualité et/ou de croyances religieuses dans l'année précédant leur tentative de suicide. La spiritualité et la religion peuvent avoir un rôle dans la trajectoire de services de ces jeunes. Comment ceci confère un effet protecteur ou encore constitue un défi reste à être approfondi. Les donneurs de soins doivent adresser ces enjeux complexes avec doigté. Déjà, les résultats générés par cette étude peuvent éclairer les politiques dans les services de santé mentale, la prévention de suicide et sensibiliser les cliniciens aux perspectives des jeunes suicidaires à propos de la spiritualité et la religion, perspectives qui pourraient influencer l'utilisation de services.

Cannabinoids (CB) are compounds structurally derived from Δ(9)-THC, the main pharmacologically active component of cannabis and marijuana. CBs produce psychoactive effects by binding the cerebral CB1 receptor (CB1R). The mammalian brain also naturally produces endocannabinoids (eCBs), intrinsic ligands of CB1R. At the start of this doctoral project, the role of the eCB system in mood regulation and the interaction between CBs and monoamines remained largely unexplored. The main aim of this project was to characterize the effects of CBs and eCBs on depression-like reactivity in murids. Since serotonin (5-HT) and norepinephrine (NE) are the major monoamine neurotransmitters implicated in depression pathophysiology and in the mechanism of action of antidepressants, we employed electrophysiological techniques to assess the in vivo effect of CBs and eCBs on 5-HT neurons of the dorsal raphe, on NE neurons of the locus coeruleus, and on postsynaptic limbic areas. The direct CB1R agonist WIN55,212-2 produced a bell-shaped effect in the rat forced swim test (FST), with low doses eliciting antidepressant-like activity while high doses being inert. This behavioural pattern was congruent with electrophysiological data. Indeed, a rapid increase of 5-HT neural activity was observed at low-doses while an attenuation below basal levels was observed at high doses. The enhanced 5-HT activity was instigated by an excitatory feedback driven by CB1Rs in the ventromedial prefrontal cortex, a limbic structure involved in stress controllability. Chronic exposure to low or high doses of WIN55,212-2 in adolescence but not in adulthood precipitated depressive- and anxiety-like reactivity that persisted in adulthood. These emotional impairments were associated with 5-HT hypoactivity and NE hyperactivity. URB597 is a novel compound that inhibits fatty acid amide hydrolase (FAAH), an enzyme that degrades anandamide, one of the major eCBs. URB597 is thus able to markedly enhance brain ananda / Les cannabinoïdes (CBs) sont des composés dérivés structurellement du Δ(9)-THC, le principe actif du cannabis. Ces drogues produisent leurs effets en se liant aux récepteurs CB1 (CB1R). Le cerveau produit également des endocannabinoïdes (eCBs) naturellement, et ceux-ci constituent les ligands intrinsèques du CB1R. Le rôle du système eCB dans la régulation de l'humeur et l'interaction entre les CBs et les monoamines étaient des sujets encore largement inexplorés. L'objectif était de caractériser l'impact de la modulation du système eCB par les CBs/eCBs sur des modèles de dépression chez le rongeur. Comme la sérotonine (5-HT) et la norépinéphrine (NE) sont les neurotransmetteurs impliqués dans la pathophysiologie et le traitement de la dépression, nous avons utilisé des techniques électrophysiologiques pour isoler in vivo l'effet des CBs/eCBs sur l'activité neurones 5-HT du raphé dorsal, des neurones NE du locus coeruleus et sur les aires postsynaptiques du système limbique. L'agoniste du CB1R, le WIN55,212-2, produit un effet bi-phasique lors du test de nage forcée (FST). Les faibles doses ont entraîné une réponse de type anti-dépresseur, alors que les doses élevées sont restées sans effet. La modulation de la 5-HT a également montré une réponse bidirectionnelle, les faibles doses ayant stimulé l'activité neuronale 5-HT, et les doses élevées la réduisant sous le niveaude base. L'augmentation de l'activité 5-HT semble mettre en action une boucle excitatrice engendrée par la stimulation des CB1R du cortex préfrontal ventromédial, qui est impliqué dans le contrôle du stress. À l'adolescence, l'exposition chronique au WIN55,212-2, a engendré une perturbation semblable à la dépression et l'anxiété qui persiste à l'âge adulte. Ces troubles émotionnels semblent être associés à une hypoactivité de la 5-HT et à une hyperactivité de la NE. L'URB597 est un composé inhibant l'acide gras amide hydrolase (HAAG),

This thesis reports a qualitative ethnographic study conducted in a small sample of local informants composed of Aymara women living in El Alto, an urban-poor setting in the outskirts of La Paz, Bolivia. The aims of the study were the following: What are the local idioms of distress, main explanatory models and help-seeking, healing and coping behaviours, with regards to the experience of distress and mental illness within this specific population? Data were collected during ethnographic fieldwork, mostly through interviews using the MINI interview. Results suggest the existence of specific idioms of distress, healing and coping behaviours, which are being adapted to the cultural and urban context of the population by the process of creolization. The most common idioms of distress and illnesses are described, i.e. preocupaciones, pena, susto, and nervios. Health inequalities and accessibility to health services are discussed, and few recommendations for practice and research are made. / Ce mémoire porte sur une étude ethnographique réalisée auprès de femmes Aymara vivant à El Alto, une ville située aux limites de La Paz, en Bolivie. La question de recherche était la suivante : Quelles sont les expressions de la détresse et de la maladie mentale au sein de cette population, de même que leurs principaux modèles explicatifs, leurs mécanismes de recherche d'aide, et leurs stratégies d'adaptation et de guérison? Les données ont été majoritairement recueillies à l'aide de l'entrevue MINI. Les résultats suggèrent l'existence de comportements et de moyens d'expression spécifiques à cette population, qui ont été adaptés à son contexte urbain et culturel par le processus de créolisation. Les expressions et maladies les plus courantes sont décrites, ex. preocupaciones, pena, susto et nervios. La présence d'inégalités sociales et l'accessibilité aux soins de santé sont discutées et des recommandations pour la recherche et la pratique sont mentionnées.