[Anxiety and depression - the role of blood-brain barrier integrity]. / Szorongás és depresszió ­ a vér-agy gát integritásának szerepe.

Among mental illnesses, anxiety disorders represent the second most frequent disorder. According to WHO Survey 2017, 264 million people suffer from their different types globally. The emergence of anxiety disorders can often increase the likelihood of developing other psychiatric illnesses such as depression, which is the most common mental illness with 300 million people affected worldwide. Although the two diseases mentioned above are widespread throughout the world, the exact physiological causes of their development and the way they are connected are not well understood. However, in order to be able to use right treatment it would be important to know the physiological background in their development. The use of anxiolytics and antidepressants is not always effective and safe, which may be due to the subtypes of these mental disorders with different etiologies. Identifying the right therapeutic strategies could be also challenging because of the phenotypic overlap between anxiety disorders and depression. Their comorbidity has been confirmed by many studies, but their exact physiological relationship is still unclear. Previous studies suggested that blood-brain barrier proteins play an important role in the development of depression and anxiety disorders and might partially explain their comorbidities. In our summary we review the current literature related to this topic.

Transcriptomic changes following chronic administration of selective serotonin reuptake inhibitors: a review of animal studies.

The review focuses on transcriptomic changes following treatment with serotonin reuptake inhibitor (SSRI) antidepressants. We aimed to overview results of the most established methods for the investigation of the gene expression alterations including northern blotting, in situ hybridization, quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), microarray and RNAseq in various brain regions and after chronic treatment protocols. In spite of some measurable changes in serotonin system mRNA expression, serotonin transporter levels remained mostly unaltered following various treatment protocols. In contrast, tryptophan hydroxylase 2 appeared to be downregulated in serotonergic nuclei, and upregulated in the midbrain regions. Alterations in serotonin receptors lack clear conclusions and changes probably reflect animal strain/substance related- and brain region dependent effects. Brain derived neurotrophic factor was upregulated following many, but not all chronic treatment regimens. GABA and glutamate genes also showed heterogeneous changes, with a surprising NMDA receptor downregulation in areas including the striatum and amygdala, known to be involved in depressive states and stress reactions. The review of the above studies suggests alterations in multiple processes, reflecting the heterogeneity of the action depending on brain area and type of SSRI, and raises the possibility of a novel grouping of antidepressant medications based on their chronic molecular profile rather than on their initial actions.