Since heterogeneity in depressed patients makes treatment decisions difficult and treatment often unsuccessful, we seek to identify certain subtypes of depression. 30 to 40% of depressed patients... Show moreSince heterogeneity in depressed patients makes treatment decisions difficult and treatment often unsuccessful, we seek to identify certain subtypes of depression. 30 to 40% of depressed patients have anger regulation problems; from irritability to anger attacks. What is the significance of anger in depression? Does it signify a subtype of depression? In the NESDA cohort, we compared a large sample of currently depressed patients with irritability to currently depressed patients without irritability. Irritable depressed patients had more symptoms of depression, more often had comorbid anxiety and had more often attempted suicide than non-irritable depressed patients. In a student sample, we investigated the role of the MAOA genotype and found that women with the high expression variant are possibly more vulnerable to anger or aggression during depression. Using acute tryptophan depletion we temporarily lowered serotonin in remitted depressed patients with and without anger regulation problems during their depression. We found no cognitive differences between the two groups, but the experiment did show us that depressed patients with anger regulation problems may be more serotonergically vulnerable. Further research is needed to elucidate best suited treatment strategies for anger regulation problems in depression Show less
In Chapter 2, results of a study are reported in which remitted depressed patients are compared to healthy controls to investigate possible residual cognitive impairments that persist into the... Show moreIn Chapter 2, results of a study are reported in which remitted depressed patients are compared to healthy controls to investigate possible residual cognitive impairments that persist into the euthymic phase. Chapter 3 will describe the effects of an alpha-lactalbumin enriched diet on cognitive performance in unmedicated recovered depressed patients and healthy controls. In Chapter 4 the effects of alpha-lactalbumin on mood and stress-induced cortisol response in unmedicated recovered depressed patients and healthy controls are reported. Chapter 5 describes the effects of low-dose and high-dose ATD on mood and neutral as well as emotional information processing in medicated remitted depressed patients. In Chapter 6, the effects of low-dose and high-dose tryptophan depletion on individual plasma tryptophan levels and the ratio tryptophan/LNAA will be discussed. In Chapter 7 the effects of ATD on heart rate variability in medicated remitted depressed patients are reported. A literature overview of studies investigating the effects of serotonin manipulations on emotional information processing and mood is given in Chapter 8. Also, evidence for a possible sequential link between serotonin induced changes in emotional information processing and mood is evaluated. Chapter 9 contains a summary and integration of the main findings, as well as methodological strengths and limitations, directions for future research and clinical implications of the findings reported in this thesis Show less
