The means by which antidepressants perform their function of making new brain cells is now understood. This it is believed will now help drug researchers develop more efficient ways to fight depression with developed medications.
It had been show by way of previous studies being carried out that the tricyclics a type of antidepressant along with the serotonin reuptake inhibitors do in fact generate new brain cells, but it was unknown up to now how this was achieved.
The new findings used Pfizer’s Zoloft and other antidepressants as their study matter. Researchers at Kings College London’s Institute of Psychiatry determined that this was done through a process involving glucocorticoid receptor (GR) which it is known is one of the key proteins used in the response to stress.
It was found that it is only with GR that new brain cells can be built.
Study Leader’s Words
Christoph Anacker, who is a doctorate student at the IoP and led the study, said,””Having identified the glucocorticoid receptor as a key player in making new brain cells, we will now be able to use this novel stem cell system to model psychiatric illnesses in the laboratory, test new compounds and develop much more effective, targeted antidepressant drugs.”
That is the result, but what will be the real knock on benefit. Given that depression is so common, and believed to be suffered by more than 120 million individuals worldwide, it is no surprise to note how it is one of the world’s leading causes of disability. The reality is that only a quarter of these sufferers have any access to a means of treatment.
It has been shown in recent studies that there is a reduction in the process of ‘neurogenesis’ in depressed patients – This ‘neurogenesis’ is the process of developing new brain cells. This lack of being able to build new cells it is believed by researchers is why low mood and impaired memory occur in depressed persons.
His team used stem cells in their work (human hippocampal) what are known as the source of new cells in the brain to show the effects play out of antidepressants, but this time on brain cells in the lab Petri dish.
The cells were treated with Zoloft which is similar in effect to Eli Lilly’s Prozac and other drugs like Paxil, these are all the SSRI class of drugs. The findings from the experiments however hold true for a different class of drugs also (serotonin and norepinephrine reuptake inhibitors (SNRIs) drugs like Pfizer’s Effexor and Eli Lilly’s Cymbalta.
Clinically Relevant Model
In a statement regarding the findings of the study Anacker said, “For the first time in a clinically relevant model, we were able to show that antidepressants produce more stem cells, and also accelerate their development into adult brain cells.”
The findings showed that the glucocorticoid receptor is positively essential; it needs to be in place for the growth to occur. This protein is then activated by the antidepressants converting immature stem cells into the needed adult brain cells.
It is evident that it will not come overnight that new antidepressants will emerge as a result of the findings, but according to those involved with the study, it will take up to five years from now for new drugs to get to the point of patient testing. The scientists conclude that whilst they do now have some tools to probe the glucocorticoid receptor, there is not yet a drug that can do it effectively. It does however give the drug companies a target to reach.