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
Hebbrecht, K.; Morrens, M.; Giltay, E.J.; Nuijs, A.L.N. van; Sabbe, B.; Ameele, S. van den 2021
Introduction: Chronic low-grade inflammation is suggested to play a pathophysiological role in bipolar disorder (BD) and its related cognitive dysfunctions. Although kynurenine (KYN) pathway... Show moreIntroduction: Chronic low-grade inflammation is suggested to play a pathophysiological role in bipolar disorder (BD) and its related cognitive dysfunctions. Although kynurenine (KYN) pathway metabolites are key inflammatory mediators, studies investigating the association between KYN metabolism and cognition in BD are scarce. We aimed to explore the relationship between KYN metabolism and cognitive functioning across different mood states in BD. Methods: Sixty-seven patients with BD (35 depressed and 32 [hypo] manic) and 29 healthy controls were included. Cognitive functioning was assessed at 3 time intervals (baseline, 4, and 8 months) assessing processing speed, sustained attention, verbal memory, working memory, and response inhibition. Plasma samples for quantification of 3-hydroxykynurenine, quinolinic acid, and kynurenic acid (KYNA) were concurrently provided. Linear mixed models were used for statistical analysis. Results: The manic group showed deficits in all assessed cognitive domains with the exception of verbal memory at all test moments. The bipolar depression group showed deficits in the processing speed at all test moments. Throughout the whole follow-up period, KYNA was significantly lower in both patient groups than in controls. Only in the bipolar depression group, low KYNA was associated with worse global cognitive functioning (B = 0.114, p = 0.02) and slower processing speed in particular (B = 0.139, p = 0.03). Conclusion: Only in the bipolar depression group, lower KYNA was associated with worse cognitive functioning. Future large-scale longitudinal studies are warranted to confirm the role of KYN metabolites in cognitive impairment in patients with BD and the possible therapeutic implications of this relationship. Show less
One of the main findings of the current thesis is the fact that psychosocial factors such as life events and low social support are not primarily predictors of subsequent mood symptoms, but also... Show moreOne of the main findings of the current thesis is the fact that psychosocial factors such as life events and low social support are not primarily predictors of subsequent mood symptoms, but also seem to occur as a result of mood symptoms . Over the last decades longitudinal studies have proven their great value for research in BD. These studies provided ample knowledge about the bipolar disease course and its associated factors. The current study contributed to this knowledge by adding different research approaches to analyse and interpret these complex longitudinal associations. These results implicate that it is difficult, and maybe not even very useful, to determine cause and effect when studying the ongoing interaction between the course of bipolar disorder and psychosocial factors. Consequently, models in which strict monocausal directions of causality are abandoned might lead to a closer approximation of the reality of the disorder and its complex interactions with the environment. The network approach may turn out to be a suitable statistical method to analyse and understand such complex associations. Show less
