A better understanding of the genetic, molecular and cellular mechanisms of brain-derived neurotrophic factor (BDNF) and its association with neuroplasticity could play a pivotal role in finding future therapeutic targets for novel drugs in major depressive disorder (MDD). Because there are conflicting results regarding the exact role of BDNF polymorphisms in MDD still, we set out to systematically review the current evidence regarding BDNF-related mutations in MDD.

We conducted a keyword-guided search of the PubMed and Embase databases, using ‘BDNF’ or ‘brain-derived neurotrophic factor’ and ‘major depressive disorder’ and ’single-nucleotide polymorphism’. We included all publications in line with our exclusion and inclusion criteria that focused on BDNF-related mutations in the context of MDD.

Our search yielded 427 records in total. After screening and application of our eligibility criteria, 71 studies were included in final analysis. According to present overall scientific data, there is a possibly major pathophysiological role for BDNF neurotrophic systems to play in MDD. However, on the one hand, the synthesis of evidence makes clear that likely no overall association of BDNF-related mutations with MDD exists. On the other hand, it can be appreciated that solidifying evidence emerged on specific significant sub-conditions and stratifications based on various demographic, clinico-phenotypical and neuromorphological variables.

Further research should elucidate specific BDNF-MDD associations based on demographic, clinico-phenotypical and neuromorphological variables. Furthermore, biomarker approaches, specifically combinatory ones, involving BDNF should be further investigated.

To evaluate the impact of genetic deletion of receptors of the counterregulatory arms of the renin–angiotensin system in depressive-like behaviours.

8–12 weeks-old male mice wild type (WT, C57BL/6J) and mice with genetic deletion of MrgD (MrgD KO) or Mas receptors (Mas KO) were subjected to the Forced Swim Test (FST) and the Tail Suspension Test (TST). Brain-derived neurotrophic factor (BDNF) levels were measured by enzyme-linked immunosorbent assay (ELISA). Blockade of Mas was performed by acute intracerebroventricular (icv) injection of its selective antagonist, A779.

No statistical difference in immobility time was observed between MrgD KO and WT male animals subjected to FST and TST. However, acute icv injection of A779 significantly increased the immobility time of MrgD KO male mice subjected to FST and TST, suggesting the involvement of Mas in preventing depressive-like behaviour. Indeed, Mas KO male animals showed increased immobility time in FST and TST, evidencing a depressive-like behaviour in these animals, in addition to a reduction in BDNF levels in the prefrontal cortex and hippocampus. No changes in BDNF levels were observed in MrgD KO male animals.

Our data showed that Mas plays an important role in the neurobiology of depression probably by modulating BDNF expression. On the contrary, lack of MrgD did not alter depressive-like behaviour, which was supported by the lack of alterations in BDNF levels.

There is currently little consensus as to how burnout is best defined and measured, and whether the syndrome should be afforded clinical status. The latter issue would be advanced by determining whether burnout is a singular dimensional construct varying only by severity (and with some level of severity perhaps indicating clinical status), or whether a categorical model is superior, presumably reflecting differing ‘sub-clinical’ versus ‘clinical’ or ‘burning out’ vs ‘burnt out’ sub-groups. This study sought to determine whether self-diagnosed burnout was best modelled dimensionally or categorically.

We recently developed a new measure of burnout which includes symptoms of exhaustion, cognitive impairment, social withdrawal, insularity, and other psychological symptoms. Mixture modelling was utilised to determine if scores from 622 participants on the measure were best modelled dimensionally or categorically.

A categorical model was supported, with the suggestion of a sub-syndromal class and, after excluding such putative members of that class, two other classes. Analyses indicated that the latter bimodal pattern was not likely related to current working status or differences in depression symptomatology between participants, but reflected subsets of participants with and without a previous diagnosis of a mental health condition.

Findings indicated that sub-categories of self-identified burnout experienced by the lay population may exist. A previous diagnosis of a mental illness from a mental health professional, and therefore potentially a psychological vulnerability factor, was the most likely determinant of the bimodal data, a finding which has theoretical implications relating to how best to model burnout.