Antidepressant treatment with mirtazapine, but not venlafaxine, lowers cortisol concentrations in saliva: a randomised open trial.

Lowering the concentrations of free cortisol in depressed patients may be an important prerequisite to prevent glucocorticoid-related sequelae of depression. We tested the hypothesis that the hypothalamus-pituitary-adrenal (HPA) system-dampening effects of venlafaxine and mirtazapine differ. We compared the course of morning (08.00h) and afternoon saliva cortisol (16.00h) in 42 mirtazapine- and 45 venlafaxine-treated depressed patients during a 1-week wash-out and a 4-week treatment period in a randomised open trial. Mirtazapine lowered afternoon cortisol from week 1 to 4. In contrast, during the course of the entire treatment period, venlafaxine did not attenuate saliva cortisol concentrations. Treatment effects of mirtazapine on cortisol concentrations did not differ in remitters and non-remitters to treatment. High baseline cortisol concentrations, on the other hand, were related to an unfavourable course during venlafaxine treatment and patients remitting during venlafaxine treatment had significantly lower afternoon cortisol concentrations in saliva, when compared to non-remitting patients. Thus, mirtazapine and venlafaxine show different effects on HPA system activity as measured by saliva cortisol. This may be of relevance with regard to physical sequelae of depression.

Cortisol metabolism in depressed patients and healthy controls.

BACKGROUND: Chronic stress as well as major depressive disorders are associated with hypercortisolemia and impaired hypothalamic-pituitary-adrenocortical axis functioning. The aim of this study was to determine whether in major depression changes in the activity patterns of local modulators of glucocorticoid action might contribute to an increase in cortisol bioavailability and if they change during antidepressant treatment and clinical response. METHODS: Concentrations of urinary total cortisol (UFF), urinary total cortisone (UFE), tetrahydrocortisone (THE), tetrahydrocortisol (THF) and allo-THF (5alpha-THF) were measured in 10-hour nocturnal urine samples of 19 depressed patients and 15 healthy controls. The activity of 11beta-hydroxysteroid dehydrogenases (11beta-HSD) as well as 5alpha- and 5beta-reductases was assessed by calculating the ratios of glucocorticoid metabolites. Patients were treated for 28 days with either mirtazapine or venlafaxine. Enzyme activity was observed during the course of treatment and compared to healthy controls. Responders to treatment were selected for this analysis. RESULTS: Depressed patients showed reduced 5alpha-reductase activity manifested as a significantly lower amount of 5alpha-THF (102.8 +/- 167.2 vs. 194.6 +/- 165.8 microg, p = 0.019). The increase in the UFF/UFE ratio (0.73 +/- 0.32 vs. 0.29 +/- 0.13, p < 0.0001) indicates reduced activity of renal 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2). During pharmacological treatment, 5alpha-reductase activity in patients returned to the level of the control group, while the decrease in 11beta-HSD2 activity persisted until day 28. CONCLUSIONS: Our results show changes in activity of intracellular modulators of steroid action in major depressive disorders, particularly a reduced activity of the intracellular cortisol-deactivating enzymes 5alpha-reductase and 11beta-HSD2. These changes suggest an increase in cortisol bioavailability within tissues.

Effect of single-dose sertraline on the hypothalamus-pituitary-adrenal system, autonomic nervous system, and platelet function.

OBJECTIVE: Pharmacological treatment with selective serotonin reuptake inhibitors (SSRIs) is thought to decrease coronary risk in patients with depressive disorder. Selective serotonin reuptake inhibitor intake may (1) attenuate the hypothalamus-pituitary-adrenal (HPA) system, (2) improve disturbances of the autonomous nervous system, and (3) dampen the aggregability of platelets. There is only limited information about the influence of acute treatment with SSRIs on these systems, which is especially important for the initiation of therapy in high-risk cardiac patients. We compared the reaction of these systems to physical stress with single-dose SSRI treatment (100 mg) with that of placebo treatment. METHODS: Using a double-blind, crossover, placebo-controlled design, we assessed HPA system activity via serum cortisol and corticotropin as well as sympathetic nervous system by determining serum norepinephrine and epinephrine levels at baseline and as a response to stress. Analysis of heart rate variability (HRV) provided information on sympathetic/parasympathetic balance. Platelet activity was measured via flow-cytometric determination of platelet surface activation markers along with the serotonin (5-HT) uptake of platelets. RESULTS: We studied 12 healthy young men under placebo and verum conditions. We found higher HPA system activity at baseline and after physical activity under sertraline when compared with placebo, no difference in sympathetic nervous system activity after physical exertion and only slightly heightened baseline epinephrine values after sertraline intake. No difference was seen between sertraline and placebo intake regarding platelet activity and 5-HT uptake, HRV, blood pressure, and HR. CONCLUSIONS: Initiating sertraline treatment increases HPA system activity and epinephrine concentrations. We found no clinically relevant effect of single-dose sertraline treatment on autonomous nervous function, platelet activity, or platelet 5-HT uptake. These findings may not be extrapolated to patients with affective or cardiac disorders or to other SSRIs.

Characterization of the neuronal dopamine transporter DAT in human blood platelets.

Compelling evidence suggests a monoaminergic dysfunction in the aetiology of various neuro-psychiatric diseases such as depression, attention deficit hyperactivity disorder (ADHD), schizophrenia, addiction and Parkinson's disease. The efficiency of monoaminergic neurotransmission is controlled by rapid and efficient reuptake of dopamine out of the synaptic cleft by specific transporters for dopamine, serotonin and noradrenaline. In case of the serotonin transporter, many investigators have determined its function and expression also on peripheral cells such as blood platelets under the assumption that changes in protein expression in these cells might reflect neuronal changes. No comparable studies have so far been performed with respect to the dopamine transporter due to the lack of information about the existence of this protein in platelets. Here, we present pharmacological, immunological as well as microarray and PCR data that human blood platelets express the dopamine transporter protein (DAT), which is identical to that first identified in neurons. Because DAT expression is modulated also in non-neuronal cells independently of gene transcription, platelets may well serve as an easy accessible peripheral system to study DAT regulation in mental diseases or during drug treatment or drug abuse.