Mental health problems among children and youths are common and have numerous negative consequences for young people and their social network. Therewith, these problems pose a social issue. GPs... Show moreMental health problems among children and youths are common and have numerous negative consequences for young people and their social network. Therewith, these problems pose a social issue. GPs play an important role in early detection and management of these problems. Insight into their clinical decision- making and, as a result, way of working would be helpful to develop methods for providing children and youths with the help they need. Previous literature suggest many doctors(-to-be), of whom some are or will become GPs, have (lived) experience related to mental health problems themselves. Previous studies also suggest having (lived) experience influences GPs’ clinical decision-making, and consequently their way of working. It would have clinical benefits for GPs and patients to explore this process. This thesis is constructed of four different articles, each contributing to answering the main question: ‘How do GPs decide on child and youth mental health problems and what is the influence of their(lived) experience regarding these problems on this decision?’ Article 1: How do GPs make decisions regarding mental health problems in children and youths? For answering this subquestion, a mixed methods design was used: interviews among 14 and an online survey among 15 GPs. GPs were asked about their clinical decision-making process on children and youths with mental health problems using three vignettes describing children and youths with mental health problems representative of clinical practice. The findings suggest GPs differ with regards to their decision- making regarding child and youth mental health problems, and that their decision-making is influenced by factors related to 1) the GP, for example if the GP approaches the problem somatically or psychosocially, if the GP considers themself competent enough to solve the problem with regards to their interest in and knowledge about youth mental health care, 2) the child and its social context, for example if the child or youth has psychiatric (co)morbidity, if the problem is likely to solve itself and if the problem could be assessed as being complex and 3) the GPs’ collaboration with other youth care providers, for example if GPs have existing collaboration agreements with these youth care providers and how they view their collaboration. Article 2: Can GPs’ decisions on child and youth mental health problems be supported by means of a decision-support method?For answering this subquestion, a literature search was conducted to retrieve studies that involved clinical decision support methods for GPs’ clinical decision-making related to mental health problems among children and youths. This systematic review yielded 25 studies on 18 clinical decision-support methods, divided into computer-based methods (such as MyGRaCE), telecommunication methods (such as CAP PC) and methods with a combination of components related to computer-based methods and telecommunication methods (such as Collaborative care for depression intervention). The article provides insight into (possible) beneficial clinical implications of clinical decision-support methods. These methods could give more insight into possible mental health problems, they could provide structured information which can be used by the GP and/or parents during their next consultation with the child or youth, and they could also decrease time and costs spent by the primary care practice and the GP. There are also less beneficial clinical implications, such as an inability for some computer-based methods to be used in emergency situations, when time is short, problems for children and youths when using computer-based methods because of their mental status, and impediment to discuss certain topics freely because the decision-support method gives too much direction to the consultation. The article describes certain considerations for GPs when choosing a decision-support method, which may indirectly have a positive impact on the implementation of such methods into general practice. For example, the GP can take into account their way of working, user flexibility of the method for the GP, the child/youth and their parent(s) with regards to understandability and ease of use, if the GP already uses a clinical decision-support method, if the GP already has collaboration agreements with youth care providers, as well as their own attitude and knowledge regarding mental health problems among children and youths.Article 3: Do doctors-to-be, among whom future GPs, have (lived) experience regarding mental health problems? Study focused on preclinical medical students.For answering this subquestion, self-report questionnaires were sent to 1311 preclinical medical students of Leiden University Medical Center to measure burnout-, depression- and anxiety-related symptoms. The article concludes that symptoms related to mental health problems are common among preclinical medical students. Burnout-related symptoms were found in 46%, depression-related symptoms in 27% and anxiety- related symptoms in 29% of preclinical medical students. Burnout-related symptoms among preclinical medical students were correlated with a sleep duration of less than 6 hours per night, low happiness and a high need for recovery after a day of study. Depression- and anxiety-related symptoms were mainly correlated with low optimism, low happiness, and a high need for recovery after a day of study. These findings suggest preclinical medical students are at risk to develop mental health problems, which can inspire universities to come up with preventive interventions.Article 4: Do doctors-to-be, among whom future GPs, have (lived) experience regarding mental health problems? Study focused on medical interns.For answering this subquestion, self-report questionnaires were sent to 709 medical interns of the same institution mentioned in article 3 to measure burnout-related symptoms. Burnout-related symptoms were found in 30% of medical interns. Burnout-related symptoms among medical interns were related to low dedication with regards to work, a high work pace and quantity, a high need for recovery after a day of work and low optimism. These correlates could be used to prevent mental health problems among medical interns by making adjustments to the medical curriculum. The articles of this thesis suggest GPs’ decision-making on mental health problems in children and youths is multifactorial and consists of objective and subjective components. Furthermore, decision-making seems to differ between GPs, which may be an explanation why there are a variety of clinical decision support methods. Some clinical decision support methods have been implemented in the context of research into general practice, like MyGRaCE, CHICA, Mobiletype, Youth StepCare, consultation-liason method(between GPs and psychiatrists), telepsychiatry consultation practice and the MC3 Program. A clinical implication is GPs can choose a decision-support method which match their personal style of clinical decision-making. However, the validity, trustworthiness and usability of available methods need to be further explored. A clinical implication with regards to medical students’ mental health comprises universities provide accessible proactive mental support to preclinical medical interns and medical interns, because many do not seek help themselves. Furthermore, universities could stimulate a stigma-reducing educational environment, for example in collaboration with the department of (Child- and Adolescent) Psychiatry. Therefore, medical students could be equipped with effective strategies to cope with mental health problems. Also, they might be made aware of their vulnerability, so that they may know their subjectivity and use their personal experiences in practice. The results of this thesis invite more (longitudinal) research on the diagnostic precision, predictive value and cost-efficiency of clinical decision-support methods. Furthermore, more research is needed on the prevalence of mental health problems among graduated doctors, like GPs, and possible effects of these problems on their way of working, their decision-making and their contacts with patients. Strengths of this thesis include exploration of a relatively unknown research area, namely GPs’ clinical decision-making regarding mental health problems among children and youths. Therefore, this thesis used multiple research methodologies and it used a practical scope. This thesis also contains several limitations, such as inclusion of a small GP population, as well as self-selection bias in the studies on preclinical medical students, medical interns and GPs. Finally, interpretation of the results of this thesis was impeded because the research has been conducted in one university, because cause and effect of results could not always be disentangled and because of low statistical power. Because having mental health problems may influence GPs’ clinical decision-making, one could explore how (future) doctors work, study and relax. Therefore, it is recommended to strive for educating balanced doctors: persons who, in collaboration with their colleagues, are – through reflection – aware of their needs and wants between professional boundaries. Show less
In this thesis, we used qualitative and quantitative research methods to gain insight in treatment decision-making for depression- and anxiety disorders in specialized mental health care. We... Show moreIn this thesis, we used qualitative and quantitative research methods to gain insight in treatment decision-making for depression- and anxiety disorders in specialized mental health care. We identified what factors are important in the decisional process, to both patients and clinicians, and how they determine decision-making outcomes, i.e., the decision to opt for: pharmacotherapy, psychotherapy, or a combination of both. We determined what preferences patients and clinicians have regarding the treatment of depression and anxiety disorders, which treatments are selected, and which factors are involved in the formation of such treatment preferences and treatment selection. Additionally, we determined what preferences patients and clinicians have regarding their role in the decisional process, their experienced decision-making roles, and the level of concordance between preferred and experienced role of patients. Finally, we examined the extent of Shared Decision-Making (SDM) in clinical practice and explored possible target points to improve SDM. Show less
The aim of this thesis was to assess the efficacy (part 1) and tolerability (part 2) of antiseizure medications (ASMs) in glioma patients with epilepsy. In addition, we aimed to get insight into... Show moreThe aim of this thesis was to assess the efficacy (part 1) and tolerability (part 2) of antiseizure medications (ASMs) in glioma patients with epilepsy. In addition, we aimed to get insight into the ASM prescription behavior and treatment policy in brain tumor-related epilepsy (part 3).First-line levetiracetam seems to be the most efficacious ASM in glioma patients, with favourable tolerability. This is demonstrated in multicenter retrospective observational cohort studies, a systematic review, and is the opinion among the vast majority of European neuro-oncology professionals. Enzyme-inducing AMSs should be avoided in glioma patients due to the high risk of adverse effects. ASM use was not independently associated with neuropsychiatric symptoms in glioma patients, but alternative factors seem to pose a greater risk for developing neuropsychiatric symptoms. If patients experience uncontrolled seizures on ASM monotherapy, levetiracetam combined with valproic acid has better efficacy than other ASM combinations in glioma patients, while toxicity is similar. Subsequently, potential add-on ASMs in glioma patients experiencing uncontrolled seizures on ASM dual therapy include clobazam, lamotrigine, and lacosamide. Show less
This thesis leads to empirical insights in the relationship between anger and aggression, on the one hand, and psychopathology, on the other hand, using robust study designs and a broad spectrum of... Show moreThis thesis leads to empirical insights in the relationship between anger and aggression, on the one hand, and psychopathology, on the other hand, using robust study designs and a broad spectrum of anger manifestations. It became clear that the occurrence of anger and aggression are common among both psychiatric outpatients, including individuals with depressive-, anxiety-, and bipolar disorders, and psychiatric inpatients, including individuals with psychotic- and personality disorders. Aggressive behaviour regularly leads to a referral to long-stay inpatient care. As supported by this thesis, the costs of aggression within long-stay wards are high. However, despite the increased awareness and efforts to reduce violence in clinical care among healthcare workers and policymakers, aggression incidents remain highly prevalent in psychiatric inpatient facilities. Research suggests diet to be a modifiable factor affecting mood and behaviour. Yet, the promising effects of nutritional supplementation on aggressive incidents found in previous studies were not replicated in psychiatric inpatients. These results strengthen the need for study of additional preventative and treatment options. Furthermore, our results underline the importance of including vulnerable populations, who are often underrepresented in RCTs, to provide evidence-based care for these groups. Show less
This thesis examines questions related to the prevalence of anxiety symptomatology and disorders in older adults, and compares two brief low-threshold psychological interventions (blended... Show moreThis thesis examines questions related to the prevalence of anxiety symptomatology and disorders in older adults, and compares two brief low-threshold psychological interventions (blended Acceptance and Commitment Therapy versus face-to-face Cognitive Behavioral Therapy) for older adults with anxiety symptoms in primary care. Show less
It is well known that military deployment can lead to mental health problems in veterans, but the long-term impact is still unclear. This thesis discusses the results of the PRISMO-study, a large... Show moreIt is well known that military deployment can lead to mental health problems in veterans, but the long-term impact is still unclear. This thesis discusses the results of the PRISMO-study, a large cohort study in a group of Dutch Afghanistan veterans with a follow-up period of ten years. It shows that at ten years post-deployment, 8% of the cohort reported severe symptoms of posttraumatic stress disorder (PTSD). Agoraphobia, anxiety, depression, and hostility symptoms are also reported more frequently at ten years post-deployment compared to pre-deployment. Furthermore, this thesis demonstrates the large heterogeneity in PTSD symptom development among veterans. Of note is the delayed onset group that experienced increasing symptom levels between five and ten years post-deployment and did not show significant symptom reduction. The results from this thesis also show that various psychological factors, such as social support, and biological factors, such as DNA methylation, are associated with the development of PTSD or other mental health symptoms after deployment. Combining these factors in a prediction model for PTSD symptoms has not led to a useful screening instrument. It does, however, offer important leads for the identification of risk factors for PTSD and the development of intervention programs. Show less
This thesis aimed to lay the foundation for a new set of Dutch mental health instruments to measure depression and anxiety in an efficient, reliable, valid, and responsive manner. More specifically... Show moreThis thesis aimed to lay the foundation for a new set of Dutch mental health instruments to measure depression and anxiety in an efficient, reliable, valid, and responsive manner. More specifically, the Dutch-Flemish PROMIS adult v1.0 item banks for Depression and Anxiety were psychometrically evaluated for computerized adaptive test (CAT) administration in the Dutch clinical and general population. CAT is a modern methodology that can be used to develop instruments that measure both efficiently and reliably as only the most appropriate questions are administered, and assessment terminates as soon as sufficient reliability is achieved. For the PROMIS CAT instruments, this was demonstrated in the thesis: measuring depression and anxiety in Dutch persons was highly efficient and reliable. Moreover, the CAT instruments were shown to measure depression and anxiety sufficiently responsive and valid as well. This even includes longitudinal validity, which has barely been studied for other Dutch mental health instruments. Overall, it was concluded that the new instruments are an improvement over available instruments. Therefore, using the PROMIS CAT instruments in clinical practice may lead to more efficient and reliable measurement that supports professionals and patients in evaluating patients' treatment. Show less
Depression shows a large heterogeneity of symptoms between and within persons over time. However, most outcome studies have assessed depression as a single underlying latent construct, using the... Show moreDepression shows a large heterogeneity of symptoms between and within persons over time. However, most outcome studies have assessed depression as a single underlying latent construct, using the sum score on psychometric scales as a total indicator for depression severity. The present dissertation aimed to expand our knowledge of depression by researching its symptom-specific longitudinal characteristics, its predictive factors, and methods for predicting depression and anxiety while taking individual symptoms into account. We demonstrated that individual depressive symptoms are not synchronized over time within patients and in groups of patients. We found that individual symptoms of depression are associated to different risk factors, as preceding chronicity, neuroticism, and inflammation were related to individual symptoms with vastly different magnitudes. Taken these findings together we have demonstrated that depressive disorder can not be characterized as an unified syndrome. Addressing depression at the syndrome level may obscure insights into both patient and symptom-specific characteristics. Our findings strengthen the idea that employing a symptom-focused approach in both clinical care and research is of value. With this dissertation, we hope to have contributed to the development of alternative ways to define and study depression and its symptoms. Show less
This dissertation describes the findings of six studies on mental health problems in the family context, specifically focusing on the associations with the parent-child relationship, parenting... Show moreThis dissertation describes the findings of six studies on mental health problems in the family context, specifically focusing on the associations with the parent-child relationship, parenting behaviors and experiences of childhood maltreatment. The aim is to better understand the risk factors, development and transmission of common psychological problems in order to contribute to prevention and treatment strategies for common psychological problems such as anxiety and depression.Overall, the findings underline the importance of the family context in the development and levels of mental health problems. In addition to the impact of one's own negative parenting experiences, including lack of warmth and experiences of emotional or physical abuse, negative parenting experiences of one's siblings are also associated with elevated anxiety and depressive symptom levels.We also found that externalizing problems of fathers and children have a negative impact on the parent-child interactions. In addition, we found that children with behavioral problems during early adolescence experience harsher parental discipline, even three years later.In the current treatment guidelines for common mental disorders, most therapies focus on the individual. An (additional) systemic approach and considering past and present family relationships in therapy, can be of additional value. For example, supporting families with interventions to improve the parent-child relationship can be helpful in the short and long term. Moreover, (early) treatment of psychological and behavioral problems of the parent or child might be beneficial for all family members. Show less
In this thesis, we have studied the potential of the zebrafish larval model in studying the ECS, as a complementary model to the existing rodent models. More specifically, we have looked at the... Show moreIn this thesis, we have studied the potential of the zebrafish larval model in studying the ECS, as a complementary model to the existing rodent models. More specifically, we have looked at the role of the ECS in regulating locomotion and anxiety, and its interaction with the hypothalamic-pituitary-interrenal (HPI) axis, or stress axis. This study has provided us with an interesting animal model which allows for pharmacological screening of Cnr1 agonists, and their involvement in the CNS, as shown by a change in locomotion, anxiety-like behavior and HPI axis activity. The zebrafish larval model can be used as a complementary model to the existing rodent animal models, to study the ECS. The zebrafish larval model brings several interesting features, such as optical transparency and possibilities for high-throughput screening. Furthermore, a complete ECS is present, there is lack of endogenous activity, allowing for exogenous compound screening, and zebrafish data is generally in line with rodent literature. Since the ECS is involved in many diseases, more research of this system may result in the discovery of novel drugs and drug targets. Show less
This thesis describes the relation of fear of childbirth (FOC), measured pre- and postpartum, with the preferred and actual place and mode of giving birth and with the use of pharmacological pain... Show moreThis thesis describes the relation of fear of childbirth (FOC), measured pre- and postpartum, with the preferred and actual place and mode of giving birth and with the use of pharmacological pain relief during labour. The studies were embedded in the Dutch obstetric system, where midwives have an independent profession and where home birth is an accepted option for women with a low-risk pregnancy. The general finding, consistent across all studies in this thesis, is that the level of FOC in pregnancy was strongly related to, and predictive of the level of postpartum FOC. Furthermore, women with severe FOC during pregnancy were prone to preferring a hospital birth, having pharmacological pain relief during labour and requesting an elective Caesarean Section. Congruence between one’s own preference (of place or mode of giving birth) and the actual delivery situation was not related to the degree of postpartum FOC. Instead, predictors for high postpartum FOC were: being referred from midwifery-led care to obstetrician-led care, emergency Caesarean Section, and a poor condition of the new-born. For guiding women with severe FOC through pregnancy and childbirth, a close collaboration between the obstetric caregiver and a psychotherapist is advised. Show less
Art therapy is an often provided but little studied treatment option in mental health care.The effectiveness of art therapy in the treatment of anxiety was studied and its working mechanisms were... Show moreArt therapy is an often provided but little studied treatment option in mental health care.The effectiveness of art therapy in the treatment of anxiety was studied and its working mechanisms were explored. Outcomes of a randomised controlled trial (n=59) showed preliminary evidence of the effectiveness of art therapy. The treatment, consisting of three months of anthroposophic art therapy, showed major reduction of anxiety symptom severity in women, compared to a wait list condition. The therapy also improved quality of life and various aspects of self-regulation: higher HRV at rest (which may indicate an overall lower stress level), improvements in emotion regulation and improvements in daily executive functioning.The second part of this PhD research focused on case report methodology and the development of tools for research within this field, with and for therapists in clinical practice, and for education. A publication guideline for case reports was developed and positively evaluated in practice. An exemplary case report of a female client with anxiety was provided.The outcomes of this research support the indication of art therapy in the treatment of anxiety and justify further studying of the effectiveness and mechanisms of art therapy. Show less
It is common in life to not perform at the very top of our cognitive abilities. This phenomenon usually exacerbates when we are under high levels of stress and in people with psychiatric disorders.... Show moreIt is common in life to not perform at the very top of our cognitive abilities. This phenomenon usually exacerbates when we are under high levels of stress and in people with psychiatric disorders. Attention to negative information is considered to play a crucial role in the development and maintenance of these disorders, especially anxiety-related disorders. Attention to negative information is not necessarily bad as it is an evolutionary function to protect us from dangerous situations. However, it can be destructive when it occurs constantly or when we need to focus on an important task. There are many situations where we have to perform difficult cognitive tasks and we worry about our performance or other people’s evaluation. Trait cognitive control, the ability to control attention and maintain a goal-relevant behaviour, is suggested to play a key role in the relationships between anxiety/stress, attention to negative information, and cognitive performance. Yet, the evidence is limited and further investigation is needed. In the current thesis, the relations between anxiety/stress, attention to emotional information, and cognitive performance will be investigated in a multidisciplinary approach, synthesizing clinical and cognitive factors and neurobiological underpinnings, while focusing on the role of trait cognitive control. Show less
The ratio between frontal resting state EEG power in the theta and beta frequency bands (theta/beta ratio, TBR) was first associated with attention deficit hyperactivity disorder (ADHD) and later... Show moreThe ratio between frontal resting state EEG power in the theta and beta frequency bands (theta/beta ratio, TBR) was first associated with attention deficit hyperactivity disorder (ADHD) and later linked to various psychological functions and cognitive/emotional processes that rely on executive cognitive control. The aim of this thesis was to further investigate TBR as a potentially useful marker for executive/attentional control, particularly when studying threat selective attention and uncontrolled thoughts. It was found that high TBR was associated with more attention to mild than high threat and low threat-interference in visual-spatial tasks containing emotional information. TBR was also negatively related to self-reported attentional control. Frontal TBR was moreover significantly higher during uncontrolled thought compared to controlled thought and this effect was also found for functional connectivity of the ‘executive control network’, which was also correlated to the controlled versus uncontrolled thought effect on TBR. However, no evidence was found to suggest that TBR can be manipulated using Neurofeedback training. These findings provide clear indications of the neuropsychological functional nature of TBR and further support the notion that TBR reflects connectivity in brain networks involved in executive control processes. Show less
The GABAergic system has been implicated in the pathogenesis of various anxiety disorders. Pharmacological treatments, like benzodiazepines, have been proven to target the GABA(A) receptors and... Show moreThe GABAergic system has been implicated in the pathogenesis of various anxiety disorders. Pharmacological treatments, like benzodiazepines, have been proven to target the GABA(A) receptors and exert quick-onset anxiolytic effect in anxiety patients. However, the side effects of these non-selective GABA(A)ergic compounds, such as sedation, postural imbalance, or potential abuse, limit their use for clinical anxiolysis. Based on the understanding of benzodiazepines’ mechanism of action, the emergence of α2,3 subtype-selective GABA(A) modulator is expected to provide a novel pharmacological approach that alleviates anxiety symptoms but spares the common undesired side effects. Most of these compounds are still in early clinical development, in which stage proof-of-mechanism studies are usually performed in healthy volunteers. The findings from our studies consistently present a similar pattern in the pharmacodynamic effect profiles of the α2,3 subtype-selective GABA(A) modulators versus those of the non-selective full GABA(A) agonist, lorazepam. Future application of anxiogenic symptom provocation models that combine subjective measurements and/or neuroendocrine biomarker assays may provide further construct validity for clinical anxiolytic effects of α2,3 subtype-selective GABA(A) modulators. Also, such findings are expected to provide insights into the translation of preclinical pharmacological properties of α2,3-subtype-selective GABA(A)ergic compounds to clinical effects in anxiety patients through human pharmacology studies. Show less
This thesis aimed to investigate the neurobiological mechanisms of adolescent onset depression and anxiety disorders. A longitudinal fMRI study design was used that included both task related brain... Show moreThis thesis aimed to investigate the neurobiological mechanisms of adolescent onset depression and anxiety disorders. A longitudinal fMRI study design was used that included both task related brain activation and resting state functional connectivity. All participants were scanned three times in a six-month period. In between scan sessions the adolescents from the clinical group received treatment as usual. Adolescents from the control group were scanned within the same time interval but did not receive treatment. During a scan session several MRI parameters were collected including task based fMRI (emotional face processing task) and resting state fMRI. We also administered several questionnaires about derpession and anxiety symptomatology. It was demonstrated that adolescents with depressive and anxiety disorders show differentiating patterns of amygdala reactivity and connectivity compared to a healthy control group. Furthermore, using a dimensional approach and taking individual differences in self-reported depression and anxiety symptoms into account highlighted the role of self-reported anxiety symptoms in amygdala reactivity during emotional faces processing. These findings indicate that the amygdala indeed is an important region involved in emotional face processing and that focusing on this region can provide further insights in the development and persistence of depressive and anxiety disorders in adolescents. Show less
Research into the relation between psychopathology and etiological factors has not yet resulted in clear findings. One of the probable causes is that most researchers use the categorical DSM-IV... Show moreResearch into the relation between psychopathology and etiological factors has not yet resulted in clear findings. One of the probable causes is that most researchers use the categorical DSM-IV Classification of mental disorders. A dimensional system has several advantages compared to categorical systems: comorbidity, lack of diagnostic agreement and arbitrary nature of used boundaries are no longer a problem. Our aim was to develop a model with dimensions that can adequately describe patients with mood- and anxiety disorders. This project used data collected through Routine Outcome Monitoring (ROM), a monitoring system for patient care. First, we validated a Dutch adaptation of an instrument based on the tripartite model. Next, we formulated an extension of this model with 5 dimensions. Consequently we presented a second model with 6 dimensions: feelings of worthlessness, fatigue, somatic arousal, anxious apprehension, phobic fear and tension. We used several analysis techniques to create a valid and reliable dimensional model. Each individual factor and the total of factors can be regarded as unidimensional measurement scales. This model can describe the clinical state of patients more specifically than the tripartite model, and can be used in subsequent research into etiological factors of psychopathology (e.g. endophenotype, genotype, trauma's, personality). Show less
The main objective of this thesis is to describe the epidemiology of long term BZD use as well as its long term consequences. This thesis is structured into three sections: In section one, the... Show moreThe main objective of this thesis is to describe the epidemiology of long term BZD use as well as its long term consequences. This thesis is structured into three sections: In section one, the correlates of BZD use, new use, chronic use, inappropriate use, and BZD dependence severity are investigated. The possible influence of the prescribing physicians on patient BZD use is also considered. In section two, the focus is on the physiological consequences of long-term BZDs use on the HPA axis and the ANS. In section three, cognitive effects of BZDs in long-term users are addressed Show less
The aim of this thesis was to clarify which aspects of depression and anxiety are related to an increased metabolic risk, and which factors contribute to these associations. Taken together, our... Show moreThe aim of this thesis was to clarify which aspects of depression and anxiety are related to an increased metabolic risk, and which factors contribute to these associations. Taken together, our findings indicate that people with more severe symptoms of depression and anxiety are at particular risk of progressive dyslipidemia and (abdominal) obesity. The higher rates of smoking and systemic inflammation among people with depression or anxiety partially accounted for their adverse metabolic profile. Dysregulations of the autonomic nervous system partly explained why users of tricyclic antidepressants displayed an increased risk of dyslipidemia and (abdominal) obesity as well, and also of hypertension. These important findings shed light on useful avenues for future research, and on preventive and therapeutic insights and directions. Show less
There is a growing awareness that research of the etiology of depressive and anxiety disorders has been hampered by their strictly categorical definition in the Diagnostic and Statistical Manual ... Show moreThere is a growing awareness that research of the etiology of depressive and anxiety disorders has been hampered by their strictly categorical definition in the Diagnostic and Statistical Manual (DSM). The DSM uses a syndrome approach, which __ although beneficial for standardization - has inherent problems that make it suboptimal for research: high rates of (artificial) comorbidity, diagnostic heterogeneity and the unrealistic assumption of discontinuity between ill and healthy. A dimensional approach that focusses on the relative severity of continuous symptom domains could be more optimal but measurement and the added value of such dimensions has been debated. Therefore, this dissertation was aimed to investigate (1) the internal validity and possibility to measure dimensions and (2) their added value in etiological and clinical research. The results showed that measurement of dimensions can be optimized using self-report questionnaires. In addition, dimensions were shown to have added value in etiological and clinical research. Because of their specific and continuous nature, dimensions could be used to uncover symptom-specific and/or non-linear association. Together, the results suggest that dimensions of depression and anxiety have internal and external validity and have the potential to improve the psychiatric research. Show less
