Exploring the link between major depressive disorder and Alzheimer’s disease

Research project: Exploring the association between major depressive disorder and Alzheimer’s disease

Lead Investigator: Dr Magdalena Sastre

  • Institution: Imperial College London  
  • Grant type: PhD studentship
  • Duration: 36 months 
  • Amount: £91,000

Why did we fund this research?

Comments from our Research Network volunteers:

With depression on the rise, especially amongst teenagers, it is important to investigate the link between major depressive disorder and Alzheimer's disease.

Project summary

Research suggests that people with major depressive disorder are at a greater risk of  dementia.

This project aims to learn more about changes in the brain that might cause this increase in risk.

The team will also investigate whether anti-depressant drugs can prevent or slow down the progression of Alzheimer’s disease in a mouse model. 

The background 

There is growing evidence to suggest that Alzheimer’s disease and major depressive disorder are linked.

In major depressive disorder, there are reductions in the volume and activity of certain brain areas. The same areas are affected in Alzheimer’s disease, so it is thought that major depressive disorder might make someone more likely to develop Alzheimer’s. 

People with Alzheimer’s disease and major depressive disorder both show reductions in the levels of certain chemicals in the brain known as neurotransmitters that send messages between nerve cells. 

Some anti-depressant drugs restore the levels of these neurotransmitters. Since the same areas of the brain are affected in Alzheimer’s disease, similar drugs might be able to treat or prevent Alzheimer’s disease.

What does this project involve?

The research team want to understand why people with a major depressive disorder seem to be at a greater risk of dementia. They will: 

  • Study the brains of people with depression (but no symptoms of dementia) who have died to look for changes that could be related to dementia 
  • Investigate if certain anti-depressant drugs taken by people with depression can reduce the signs of dementia in the brains of a mouse model of Alzheimer’s disease.  

Amyloid plaques are found in the brains of people with Alzheimer’s disease and can interrupt cell-to-cell signalling.

The team hypothesise that people with major depressive disorder have alterations in the pathways that are involved in the formation of amyloid plaques. 

To investigate this link, the team will:

  • Analyse the brains of people with major depressive disorder and healthy control participants to see if the people with major depressive disorder show changes in amyloid in the brain and understand more about why that might be. 
  • Investigate whether anti-depressant drugs are effective in treating Alzheimer’s disease. 

How will this project help people with dementia?

If anti-depressants are shown to be effective in treating Alzheimer’s, this project could pave the way for developing new treatments for Alzheimer’s disease.

It could also support the notion of giving people with depression anti-depressants to decrease the chance of them developing dementia.