Angiogenesis in refractory depression: A possible phenotypic target to avoid the blood brain barrier

Major depressive syndrome (so-called depression) is a common but serious mental disease that causes low mood. Most patients are treatable, mainly because of high response rates for medicines such as selective serotonin-reuptake inhibitors (SSRIs). However, there are still a considerable number of patients with refractory or drug-resistant depression. On the other hand, recent findings suggest that angiogenesis, i.e., making new blood vessels, could have an important role in the recovery from depressive disorders, at least in part. It has been reported that the brain capillaries are physiologically capable of undergoing angiogenesis upon stimuli such as exercise and SSRIs seem to accelerate brain angiogenesis. Drugs targeting angiogenesis may possibly be another good concept. In addition, the blood brain barrier (BBB), which is a major obstacle for drug development for the central nervous system, would be circumvented. Here I summarize the reports that relate angiogenesis to a cure for major depression and discuss some of the potential molecular targets.