Completed Pregnancy, Children & Inherited Conditions Mental Health

Allosteric modulators of extrasynaptic delta-GABAA receptors for the treatment of postpartum depression

In plain English

AI plain-English summary

A single 60-hour intravenous infusion of the drug Brexanolone can relieve postpartum depression, but its high cost, severe side effects, and need for hospitalisation mean it reaches very few of the 15–20% of new mothers who develop the condition. The problem is that Brexanolone works by flooding the brain with a natural chemical called allopregnanolone, which alters many related proteins—the GABAA receptors. Some of these proteins produce the antidepressant effect, but others cause the side effects. This project aims to find chemicals that only alter the extrasynaptic GABAA receptors responsible for the benefit, leaving the side-effect-causing subtypes untouched. The researchers will test candidate compounds on intact mouse and rat brain tissue to confirm this selectivity. If successful, this work could lead to an oral or short-duration drug for postpartum depression that is safer, cheaper, and widely accessible outside a hospital setting. That would represent a step-change in maternal mental health treatment. This is early-stage fundamental science—identifying the right chemical tools and proving they work in brain tissue—but it is a necessary first step before any clinical development can begin.

View original technical description
Postpartum depression (PPD), which is a more severe version of the common "baby blues", occurs in 15-20% of mothers and is associated with symptoms such as depressed mood, anxiety and feelings of worthlessness. Although the cause is unknown, it is hypothesised that PPD is triggered by the reduction after birth in the amount of a chemical called allopregnanolone which is well-known to have an effect on brain function and mood. This hypothesis was recently confirmed when an allopregnanolone-supplement strategy was shown to be effective in alleviating the symptoms of depression and was approved by the US Food and Drug Adminstration for the treatment of mothers with PPD. However, the drug, which is called Brexanolone (but is simply a proprietary form of allopregnanolone), has a number of significant issues associated with its use, not least of which are the need for a 60-hour intravenous infusion, serious side effects and a very high cost. As a result, Brexanolone has limited availability to the wider PPD patient population. Brexanolone works by altering the function of a group of proteins in the brain called the GABAA receptors (GABAARs). Evidence suggests that one type of these proteins, the so-called extrasynaptic GABAARs are responsible for the beneficial effects of Brexanolone in the treatment of PPD whereas other other subtypes of GABAAR proteins are responsible for the side effects. In this proposal we aim to identify chemicals that alter the function of the extrasynaptic GABAAR proteins but do not affect those proteins responsible for the side-effects. As the next step in advancing such compounds towards the clinic and the PPD patient population, we will also demonstrate that these chemicals selectively alter the function of the extrasynaptic GABAAR proteins in intact mouse and rat brain tissue. If this project is successful and we then achieve our ultimate long-term goal of identifying a drug for treating PPD, then we believe that it could provide a step-change in the treatment of postpartum depression. As such, this present proposal represents an important first step in the process of making a significant impact within the field of maternal mental health.

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Researchers

Ian Jones (Co-Investigator)Jeremy Lambert (Co-Investigator)John Atack (Principal Investigator)Simon Ward (Co-Investigator)Stephen Martin (Co-Investigator)

Related Research

Grants with similar aims, by meaning.

Allosteric modulators of extrasynaptic O-GABAA receptors for the treatment of postpartum depression
Developing small molecules as a neurosteroid replacement strategy for treating postpartum psychosis
GABAB receptor negative allosteric modulators: A novel approach to developing non-monoaminergic antidepressants
Investigating a placental origin for pregnancy and postpartum mood disorders:
Neurosteroids and GABA-A receptors and their roles in neuropsychiatric disorders

Original classification

Research Grant

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