Depressie en angststoornissen, zoals major depressive disorder, paniekstoornis, sociale angststoornis en gegeneraliseerde angststoornis, vallen onder de meest voorkomende psychiatrische... Show moreDepressie en angststoornissen, zoals major depressive disorder, paniekstoornis, sociale angststoornis en gegeneraliseerde angststoornis, vallen onder de meest voorkomende psychiatrische ziektebeelden. Door middel van neuroimaging onderzoek zoals structurele en functionele MRI (fMRI) is het mogelijk om op een non-invasieve manier de onderliggende neurobiologie van deze stoornissen in kaart te brengen. Op basis van dergelijk onderzoek werden ruim 15 jaar geleden enkele neurobiologische modellen opgesteld waarin werd voorgesteld dat het goed of juist niet goed hersengebieden een belangrijke bijdrage leverde aan het ontstaan en/of instandhouden van depressie en angst. In de loop der jaren zijn nieuwe MRI technieken ontwikkeld. Met behulp van structurele MRI en resting-state fMRI, waarmee connectiviteit tussen hersengebieden onderzocht kan worden, heb ik gekeken naar anatomische en functionele hersenafwijkingen bij volwassenen en jongeren met depressie en/of angststoornissen. Doel was te bepalen of de reeds bestaande neurobiologische modellen bevestigd danwel aangepast of aangevuld zouden kunnen worden met recent ontwikkelde onderzoeksmethoden. De resultaten van mijn studies bevestigden grotendeels de betrokkenheid van de hersengebieden in de modellen, maar wezen tevens op een rol voor uitgebreidere netwerken van hersengebieden dan in de modellen werd verondersteld. Show less
The aim of this thesis was to identify the neural mechanisms that enable a person to adaptively respond to, and recover from stress, which was studied in healthy controls, in people with increased... Show moreThe aim of this thesis was to identify the neural mechanisms that enable a person to adaptively respond to, and recover from stress, which was studied in healthy controls, in people with increased vulnerability or resilience to stress-related disorders, and in people with depression or PTSD, using magnetic resonance imaging (MRI). In most of the studies, a specific MRI method was employed, with which it is possible to assess how different brain regions communicate with each other (i.e., functional connectivity) when the brain is initiating or regulating stress responses. Structure, activity, and connectivity of the amygdala, a small brain region important for stress reactivity, was of main interest. The results show how stress influences information processing, and causes changes in the communication between brain areas, even long after the stressful event ended. Furthermore, personality dimensions associated with increased vulnerability or resilience to affective disorders were associated with changes in brain networks involved in emotion processing and regulation. Finally, smaller amygdala volumes were found in women with PTSD, while reduced integrity of affective brain networks was demonstrated in depression. Together, these results open important new avenues for future research into the short and long term effects of stress on the brain. Show less
It is well known that complex mental abilities develop at least until late adolescence. Yet, there are also skills that children master perfectly, sometimes even better than adults. The goal of... Show moreIt is well known that complex mental abilities develop at least until late adolescence. Yet, there are also skills that children master perfectly, sometimes even better than adults. The goal of this thesis was to learn more about the possibilities of cognitive functioning in children and young adults, and the constraints set by the developing brain. An fMRI training approach was used to examine age- and experience-related effects in the development of working memory and resting-state functional connectivity. More specifically, we studied age differences on task performance and brain activation during a working memory task with various demands and difficulty levels, both before and after 6 weeks of practice with the task. In addition, to learn more about the interaction between different brain regions, we also examined age differences and practice effects on functional connectivity during resting-state. Show less
