Background. There are inconclusive findings regarding whether danger and loss events differentially predict the onset of anxiety and depression. Method. A community sample of adolescents and young adults (n=2304, age 14–24 years at baseline) was prospectively followed up in up to four assessments over 10 years. Incident anxiety and depressive disorders were assessed at each wave using the DSM-IV/M-CIDI. Life events (including danger, loss and respectively mixed events) were assessed at baseline using the Munich Event List (MEL). Logistic regressions were used to reveal associations between event types at baseline and incident disorders at follow-up. Results. Loss events merely predicted incident ‘pure’ depression [odds ratio (OR) 2.4 per standard deviation, 95% confidence interval (CI) 1.5–3.9, p<0.001] whereas danger events predicted incident ‘pure’ anxiety (OR 2.3, 95% CI 1.1–4.6, p=0.023) and ‘pure’ depression (OR 2.5, 95% CI 1.7–3.5, p<0.001). Mixed events predicted incident ‘pure’ anxiety (OR 2.9, 95% CI 1.5–5.7, p=0.002), ‘pure’ depression (OR 2.4, 95% CI 1.6–3.4, p<0.001) and their co-morbidity (OR 3.6, 95% CI 1.8–7.0, p<0.001). Conclusions. Our results provide further evidence for differential effects of danger, loss and respectively mixed events on incident anxiety, depression and their co-morbidity. Since most loss events referred to death/separation from significant others, particularly interpersonal loss appears to be highly specific in predicting depression.

Aims. To prospectively examine whether negative life events (NLE) and low perceived coping efficacy (CE) increase the risk for the onset of various forms of psychopathology and low CE mediates the associations between NLE and incident mental disorders. Methods. A representative community sample of adolescents and young adults (N = 3017, aged 14–24 at baseline) was prospectively followed up in up to three assessment waves over 10 years. Anxiety, depressive and substance use disorders were assessed at each wave using the DSM-IV/M-CIDI. NLE and CE were assessed at baseline with the Munich Event List and the Scale for Self-Control and Coping Skills. Associations (odds ratios, OR) of NLE and CE at baseline with incident mental disorders at follow-up were estimated using logistic regressions adjusted for sex and age. Results. NLE at baseline predicted the onset of any disorder, any anxiety disorder, panic disorder, agoraphobia, generalised anxiety disorder, any depression, major depressive episodes, dysthymia, any substance use disorder, nicotine dependence and abuse/dependence of illicit drugs at follow-up (OR 1.02–1.09 per one NLE more). When adjusting for any other lifetime disorder prior to baseline, merely the associations of NLE with any anxiety disorder, any depression, major depressive episodes, dysthymia and any substance use disorder remained significant (OR 1.02–1.07). Low CE at baseline predicted the onset of any disorder, any anxiety disorder, agoraphobia, generalised anxiety disorder, any depression, major depressive episodes, dysthymia, any substance use disorder, alcohol abuse/dependence, nicotine dependence and abuse/dependence of illicit drugs at follow-up (OR 1.16–1.72 per standard deviation). When adjusting for any other lifetime disorder prior to baseline, only the associations of low CE with any depression, major depressive episodes, dysthymia, any substance use disorder, alcohol abuse/dependence, nicotine dependence and abuse/dependence of illicit drugs remained significant (OR 1.15–1.64). Low CE explained 9.46, 13.39, 12.65 and 17.31% of the associations between NLE and any disorder, any depression, major depressive episodes and dysthymia, respectively. When adjusting for any other lifetime disorder prior to baseline, the reductions in associations for any depression (9.77%) and major depressive episodes (9.40%) remained significant, while the reduction in association for dysthymia was attenuated to non-significance ( p-value > 0.05). Conclusions. Our findings suggest that NLE and low perceived CE elevate the risk for various incident mental disorders and that low CE partially mediates the association between NLE and incident depression. Subjects with NLE might thus profit from targeted early interventions strengthening CE to prevent the onset of depression.

The primary and secondary objectives of the Early Developmental Stages of Substance Abuse Study (EDSP) are described along with a detailed description of the overall design, special design features and instruments used. The EDSP is a 5-year prospective study with three waves of assessments. Special design features are the linkages with family genetic investigations as well as neuroendocrinological stress tests in high-risk subjects. Overall, 3,021 adolescents and young adults aged 14–24 years are included. The response rate for the baseline investigation was 71%. Diagnostic assessments were made by using a modified lifetime (baseline) and 12-month change version of the WHO-CIDI, adjusted for DSM-IV. Modifications refer to a more detailed quantitative assessment of symptoms and substance use variables as well as the inclusion of questions to assess course of disorders and subthreshold diagnostic conditions.

The objectives of the community-based Early Developmental Stages of Psychopathology (EDSP) Study are described along with a detailed account of the overall design, special design features, sample characteristics and instruments used. The EDSP employed a prospective-longitudinal design to study substance use and other mental disorders in a representative population sample of 3,021 subjects aged 14–24 years (birth cohorts 1970–1981) at ‘baseline’ – the outset of the study. Two follow-up investigations were conducted after the baseline investigation covering an overall period of 3–4 years. Special design features are the linkage with a family supplement (EDSP-FS) as well as neurobiological laboratory studies of high-risk subjects.

Objectives: To determine risk factors of incident onset of use, abuse and dependence of cannabis in a community sample of adolescents and young adults. Methods: Risk factors were examined in a prospective longitudinal design across 4 years in a representative sample (N=2446) aged 14-24 at the outset of the study (EDSP). Patterns of DSM-IV defined cannabis use, abuse and dependence were assessed with the Composite International Diagnostic Interview (M-CIDI). Potential risk factors were assessed at baseline. Incident cannabis use, abuse and dependence at second follow-up (on average 42 months after baseline) were the main outcome measures in this study. Associations were analyzed with logistic and negative binomial regressions. Results: Using 11 of a total of 56 variables examined, the predictive value of the final multiple logistic regression for incident cannabis use was moderately good (area under the ROC curve=0.78). Cannabis use frequency was predicted in the final model by 18 variables, cannabis abuse by two variables in the younger subsample and nine factors in the older group, and dependence by eight variables (dependence: ROC curve area=0.97). Incident cannabis use was predicted mainly by availability of drugs, peers’ drug use, a more ‘positive’ attitude towards future drug use, and regular previous use of licit drugs, while cannabis dependence was predicted primarily by parental death before age 15, deprived socio-economic status, and baseline use of other illicit drugs. Conclusion: Different factors predict the onset or severity of cannabis use and the progression to abuse and dependence. In addition to well-documented risk factors such as peer group pressure, drug availability, and low self-esteem, findings suggest that family history (e.g. parental mental disorders, early parental death), and prior experiences with legal drugs play a significant role in the initiation of cannabis consumption and the transition to cannabis use disorders in adolescents and young adults. Findings suggest that early intervention and prevention might be improved by better targeted treatment.

Les résultats de la recherche portant sur les impacts de la jalousie dans les relations de couple sont mixtes et ne nous permettent pas d’en connaître son impact sur le désengagement romantique, ou la perte de sentiments amoureux, qui est un problème fréquemment mentionné par les couples qui consultent en thérapie conjugale. Par le biais d’un devis longitudinal et dyadique, cette étude a examiné l’association entre la jalousie et le désengagement romantique, en tenant compte de la satisfaction relationnelle à titre de facteur modérateur. Concernant les effets acteurs, vu l’état actuel de la recherche portant sur l’effet de la jalousie sur différentes variables relationnelles, aucune hypothèse n’a été émise concernant la direction de l’association entre les trois composantes de la jalousie et les changements dans le désengagement romantique chez l’individu 9 mois plus tard. Cependant, nous avons émis l’hypothèse que la satisfaction relationnelle modèrerait cette association à travers le temps. Concernant les effets partenaires, nous avons émis l’hypothèse que de hauts niveaux de jalousie chez l’individu seraient associés à une augmentation du désengagement romantique chez son partenaire à travers le temps. Nous avons également considéré les différences de genre dans ces effets acteurs et partenaires. La jalousie, le désengagement romantique et la satisfaction relationnelle de 141 couples de sexes mixes ont été mesurés à deux temps de mesures sur une période de 9 mois. Des analyses acheminatoires basées sur le Modèle d’interdépendance acteur-partenaire ont ensuite été effectuées afin de vérifier les questions et hypothèses de recherche. Les résultats ont montré que la jalousie émotionnelle chez la femme était associée à une diminution de leur propre désengagement romantique à travers le temps (β = -.154, p = .029). De plus, la satisfaction relationnelle modérait l’association entre la jalousie émotionnelle et le désengagement romantique, c’est-à-dire que les femmes rapportaient une diminution de leur désengagement lorsqu’elles rapportaient être faiblement (B = -0.016, p = .004) ou moyennement satisfaites dans leur relation (B = -0.011, p = .032). L’interaction n’était pas significative pour les femmes qui étaient très satisfaites (B = -0.006, p = .257). La satisfaction relationnelle modérait aussi l’association entre la jalousie cognitive et le désengagement romantique chez la femme. La jalousie cognitive était associée à une augmentation du désengagement, mais seulement chez les femmes qui rapportaient être extrêmement satisfaites dans leur relation (4 ÉT au-dessus de la moyenne; B = 0.024, p = .048). Par ailleurs, la jalousie comportementale de la femme permettait de prédire une augmentation du désengagement chez son partenaire (β = .142, p = .039). Les résultats suggèrent que la jalousie serait un facteur à considérer pour comprendre le désengagement chez les couples de longue durée au fil du temps. De plus, cette association serait modérée par la satisfaction relationnelle, mais pour les femmes seulement. Des études supplémentaires seront nécessaires afin d’identifier d’autres facteurs relationnels et personnels pouvant contribuer au désengagement romantique chez l’homme. / Research examining jealousy among couples provides mixed findings regarding its association with relationship outcomes and does allow an understanding of its role in romantic disengagement. Also referred to the process of falling out of love, disengagement is frequently reported by couples who seek relationship therapy. Using a dyadic and prospective design, the purpose of this study was to examine the association between jealousy and romantic disengagement while considering relationship satisfaction as a potential moderating factor. Since the current literature provides mixed findings about the effect of jealousy on relationship outcomes, no a priori hypotheses were proposed about the directionality of the associations between the three components of jealousy assessed at baseline, and changes in romantic disengagement for the individual 9 months later (actor effects). However, we expected that relationship satisfaction would moderate this association. At the dyadic level, we expected that high levels of jealousy in the individual would be associated with an increase in their partner’s level of disengagement at follow-up (partner effects). Finally, we also considered gender differences in actor and partner effects. Jealousy, romantic disengagement, and relationship satisfaction were assessed twice among 141 mixed-sex couples over a nine-month period. Path analyses using the Actor-Partner Interdependence Model were conducted to verify the hypotheses and research questions. Emotional jealousy was related to a decrease in one’s romantic disengagement over time for women (β = -.154, p = .029). Moreover, relationship satisfaction moderated the association between emotional jealousy and disengagement— women who reported low (B = -0.016, p = .004) to moderate (B= -0.011, p = .032) levels of relationship satisfaction experienced a decrease in their disengagement, but not when they reported being highly satisfied (B = -0.006, p = .257). Relationship satisfaction also moderated the association between cognitive jealousy and romantic disengagement for women—jealous thoughts were associated with an increase in romantic disengagement when women reported extremely high levels of satisfaction (4 standard deviations above the mean: B = 0.024, p = .048). Additionally, women’s behavioral jealousy predicted an increase in their partner’s disengagement (β = .142, p = .039). The findings suggest that considering jealousy increases our understanding of disengagement and how it unfolds over time among long-term couples. Moreover, relationship satisfaction would moderate the association between jealousy and disengagement, but only for women. Further research is required to identify other relational or personal factors that could contribute to romantic disengagement in men.

Objective: Prospective study designs ideally allow patients to be followed from the first manifestations of the illness or even from an at-risk stage. It can thus provide data on the predictive value of changes in clinical symptomatology, cognition or further biological markers to broaden our understanding of the etiopathology and symptomatic trajectory of bipolar disorders. The scope of this narrative review is to summarize evidence from prospectively collected data on psychopathological and other clinical and biological changes in the early developmental course of bipolar disorders. Methods: The narrative review was based on a literature search conducted in February 2016 within the PubMed library for prospective study data of persons in antecedent and early manifest stages of manifest bipolar disorder published within the last 15 years. Results: A total of 19 prospective studies were included. Regarding psychopathological features; personality, temperament and character traits as well as changes in sleep and circadian rhythm, the evidence suggests that risk factors for the development of bipolar disorder can already be described and should be studied further to understand their interaction, mediation with other factors and timing in the developmental process of bipolar disorder. Apart from the positive family history, childhood anxiety, sleep problems, subthreshold (hypo)manic symptoms and certain character traits/emotionality should be identified and monitored already in clinical practice as their presence likely increases risk of bipolar disorder. Up to date no substantiated evidence was found from prospective studies addressing cognitive features, life events, immunological parameters and morphological central nervous system changes as potential risk factors for bipolar disorder. Conclusion: For an improved understanding of episodic disorders, longitudinal data collection is essential. Since the etiology of bipolar disorders is complex, a number of potential risk factors have been proposed. Prospective studies addressing this spectrum and resilience factors are critical and will be best conducted within multi-site research networks or initiatives.

Objective: The present study investigated, for the first time, event- and time-based prospective memory (PM) in the same sample of adults with ADHD within one paradigm using parallel task constraints. Method: A total of 25 individuals with ADHD and 25 matched neurotypical controls completed a computerized version of the Dresden Breakfast Task, which required participants to prepare breakfast following a set of rules and time restrictions. Results: Although groups did not differ in event-based PM, results demonstrated a large-sized impairment in individuals with ADHD in time-based PM. Conclusion: Findings suggest a task-specific impairment in PM functioning and are discussed in an executive control framework of neurocognitive functioning in ADHD. (J. of Att. Dis. 2014; 18(7) 617-624)

Masters of Commerce / Despite having a significant agri-food sector, South Africa is faced with strong food security issues related to high inequalities and the legacy of the apartheid regime. The South African food system finds itself at risk of alienating the majority of its citizens from realizing their right to access food granted by the South African Constitution (1996) Section 27(1)(b). Increasing poverty, unemployment and poor governance are making it harder for ordinary South African citizens to put safe and nutritious food on the table. Part of the food security issue in South Africa is that there is an inefficiency in public policies. It can be explained by the extreme segmentation of public action between departments and also by the limitations and ineffectiveness of decentralization resulting in little to no involvement from local governments. Like most socio-economic issues, the effects of food insecurity are first experienced on the ground at the local level where municipalities are at the forefront. The absence of effective policy around food security and food systems at the local level in South Africa leaves room for research on improved local food governance. Municipalities should be best suited to understand the consequences of food insecurity and could therefore use some of their constitutional mandate which provides some room for manoeuvre with regard to food issues. The aim of this study is to raise awareness of food security issues at the municipal level and to identify ways to facilitate engagement by municipalities. Its main objective was to adopt a foresight approach, using scenarios with local actors, and to understand how it can help improve the engagement of municipalities and citizens in the food security debate and take possible action. This research has made use of an existing collaboration between the Centre of Excellence in Food Security (CoE-FS) and the South African Local Government Association (SALGA) developed in the Western Cape. The collaboration focuses on the understanding of the food policy space in South Africa, the results of existing policies, and how the co-production of knowledge between stakeholders, notably at the local level, can contribute to policy improvement.

Cette thèse fournit une illustration numérique de la façon dont une taxe carbone pourrait affecter le PIB, l’emploi, les émissions de CO2 et les inégalités socio-économiques en Afrique du Sud. Elle utilise un modèle d’équilibre général calculable « hybride » en économie ouverte par projection en un seul pas de temps de 2005 à 2035. Le modèle représente des économies de second rang, notamment des rigidités sur le marché du travail liées aux niveaux de qualification et dans la production électrique. Sept scénarios basés sur des modalités différentes de recyclage de la taxe carbone sont analysés, plus une option d’investir une partie des revenus de la taxe dans l’amélioration des qualifications de la force de travail.L’analyse montre que sous hypothèse standard de changement technique, une taxe carbone de 100 ZAR par tonne de CO2 environ a peu d’impact négatif sur le PIB et l’emploi lorsqu’elle est associée à un mode de recyclage des revenus approprié : subventionner le facteur travail et réduire les taxes sur les profits des entreprises pourrait conduire aux meilleurs résultats macroéconomiques, mais ne réduit pas les inégalités. Des mesures supplémentaires sont nécessaires pour réduire la « pauvreté énergétique ». Pour atteindre le NDC d’Afrique du Sud au titre de l’Accord de Paris, un taux de taxe d’environ 300 ZAR ou 55$ par tonne de CO2 serait nécessaire. Toutefois, un tel taux pourrait avoir un impact significatif sur la croissance du PIB. En même temps, sans changement de la tendance de croissance de la productivité du travail, ce PIB plus faible conduirait à un chômage plus élevé que dans le cas de référence. Une politique d’investissement de 7.5 milliards de ZAR de revenus carbone dans les qualifications de la main d’œuvre, avec l’objectif d’augmenter l’accès à la formation de haut niveau et de réduire le manque de salariés très qualifiés, pourrait avoir un effet très positif sur la croissance du PIB.Le progrès technologique, les préférences des consommateurs et le contexte international, limitent la capacité de l’économie à se restructurer et se décarboner et incidemment à réduire les impacts négatifs de la taxe carbone sur la croissance du PIB. Une véritable évaluation du changement technologique futur serait pertinente pour tous les secteurs et facteurs de production. Ces résultats impliquent aussi que la politique climatique internationale doit traiter la question des transferts de technologie et celles des potentiels différents de décarbonation sérieuse à l’échelle nationale. / This PhD thesis gives a numerical illustration of how a carbon tax affects South African GDP, employment, CO2 emissions and socio-economic inequality. It uses a “hybrid” computable general equilibrium model of an open economy in a one-step projection from 2005 to 2035. It models second-best economies, notably skill-related rigidities in the labour market and in production of electricity. Seven scenarios for recycling of carbon tax revenue are analysed, plus an option to invest a part of tax revenue in improvement of skills of labour.The analysis shows that under conventional assumptions about technological change, a carbon tax of around 100 ZAR2005 (18 USD2013) per tonne of CO2 will have little negative consequences for GDP and employment, when combined with the right type of tax revenue recycling: Labour subsidies and company profit tax reduction likely lead to the best macro-economic outcomes, though do not reduce inequality. Additional measures are needed to reduce “energy poverty”. To achieve South Africa’s NDC of the Paris Agreement, a carbon tax rate of around 300 ZAR2005 or 55 USD2013 per tonne of CO2 is necessary. However, this could have serious impacts on GDP growth. Also, without a change in the trend of increasing labour productivity, such lower GDP will lead to higher unemployment than in the reference case. An investment in skills of 7.5 billion ZAR2005 of annual Ctax revenue, with the objective of increasing access to high quality education and reducing the high skill labour shortage, if fond to have a very positive impact on GDP growth. However better calibration data is required.The findings of this PhD thesis furthermore call for thorough examination of what type of technological change could be expected for South Africa. Technological progress, consumer preferences and international circumstances limit the economy’s capacity to restructure and decarbonise and therefore to reduce negative consequences of carbon taxation for GDP growth. Proper assessment of future technological change is relevant for all sectors and inputs. Examples are given which show that energy and materials efficiency have an important role for future GDP growth under carbon constraints, because they determine the economy’s flexibility to reduce energy consumption and to substitute it, e.g. by labour. This finding normally holds not only for South Africa, but also for the rest of the world. These results also imply that international climate policy has to address technology transfer and the different potentials of national economies to decarbonise seriously.