MORC1 exhibits cross-species differential methylation in association with early life stress as well as genome-wide association with MDD

Early life stress (ELS) is associated with increased vulnerability for diseases in later life, including psychiatric disorders. Animal models and human studies suggest that this effect is mediated by epigenetic mechanisms. In humans, epigenetic studies to investigate the influence of ELS on psychiatric phenotypes are limited by the inaccessibility of living brain tissue. Due to the tissue-specific nature of epigenetic signatures, it is impossible to determine whether ELS induced epigenetic changes in accessible peripheral cells, for example, blood lymphocytes, reflect epigenetic changes in the brain. To overcome these limitations, we applied a cross-species approach involving: (i) the analysis of CD34+ cells from human cord blood; (ii) the examination of blood-derived CD3+ T cells of newborn and adolescent nonhuman primates (Macaca mulatta); and (iii) the investigation of the prefrontal cortex of adult rats. Several regions in MORC1 (MORC family CW-type zinc finger 1; previously known as: microrchidia (mouse) homolog) were differentially methylated in response to ELS in CD34+ cells and CD3+ T cells derived from the blood of human and monkey neonates, as well as in CD3+ T cells derived from the blood of adolescent monkeys and in the prefrontal cortex of adult rats. MORC1 is thus the first identified epigenetic marker of ELS to be present in blood cell progenitors at birth and in the brain in adulthood. Interestingly, a gene-set-based analysis of data from a genome-wide association study of major depressive disorder (MDD) revealed an association of MORC1 with MDD.

Changes of serum concentrations of brain-derived neurotrophic factor (BDNF) during treatment with venlafaxine and mirtazapine: role of medication and response to treatment

INTRODUCTION

Depression, stress and antidepressant treatment have been found to modulate the expression of brain-derived neurotrophic factor (BDNF). Recent research suggests that serum BDNF concentration is reduced in depression and that antidepressant treatment leads to an increase in serum BDNF concentration.

METHODS

We studied depressed patients receiving a randomized antidepressant treatment with either mirtazapine (n=29) or venlafaxine (n=27) for 28 days in a prospective design. Changes in the concentrations of serum neurotrophins in response to antidepressant treatment were assessed.

RESULTS

There was a significant "treatment" by "medication" interaction effect on BDNF serum concentrations that indicated a decline of BDNF in venlafaxine-treated patients (7.82±3.75-7.18±5.64 ng/mL), while there was an increase in mirtazapine-treated patients (7.64±6.23-8.50±5.37 ng/mL). There was a trend for a "treatment" by "remission" interaction with a favourable clinical course being related to increasing serum BDNF.

DISCUSSION

Changes in BDNF serum concentrations as a result of antidepressant therapy depend on the antidepressant and potentially on the clinical course.

Duloxetine for major depressive episodes in the course of psychotic disorders: an observational clinical trial

Patients with psychotic disorders often suffer from intercurrent major depressive episodes (MDE). Case reports suggested successful antidepressive treatment with duloxetine, a selective dual reuptake inhibitor of serotonin and norepinephrine. We initiated this open prospective clinical trial to evaluate efficacy, safety and tolerability of this approach. Patients with a psychotic lifetime diagnosis suffering from mildly severe MDE were treated with duloxetine over a period of 6 weeks. We evaluated effects on mood, monitored the psychotic psychopathology and assessed side effects, basal clinical and pharmacological parameters. Twenty patients were included and experienced a significant improvement of their MDE during the observation period (Calgary Depression Scale for Schizophrenia and Hamilton Depression Scale). Psychotic positive symptoms remained stably absent, while negative syndrome and global psychopathology considerably improved (Positive and Negative Syndrome Scale). In general, the treatment was well tolerated, serum prolactin levels stayed unchanged, but pharmacokinetic interactions with a number of antipsychotic agents were observed. This open prospective evaluation showed antidepressive efficacy of duloxetine in patients with co-morbid psychotic disorders. With regard to the psychotic disorder, the treatment appears to be safe and well tolerable. Further investigations should involve a randomized control group.