Skip to main content

Main menu

  • About Us
    • Leadership
    • Our Team
    • Vision, Mission and Values
    • Health and Economic Impact
    • Strategic Plan
  • Our Research
    • Research Focus
      • Brain Health
      • Cancer
      • Cardiovascular Conditions and Diseases
      • Digital Health
      • Health Policy
      • Immunity and Infectious Diseases
      • Joint Health and Mobility
      • Respiratory and Lung Health
      • Spinal Cord Injury and Rehabilitation
    • Research Centres and Programs
      • BC Centre on Substance Use
      • Centre for Aging SMART
      • Centre for Cardiovascular Innovation
      • Centre for Clinical Epidemiology and Evaluation
      • Centre for Lung Health
      • Djavad Mowafaghian Centre for Brain Health
      • Immunity and Infection Research Centre
      • International Collaboration On Repair Discoveries
      • Ovarian Cancer Research Centre
      • Vancouver Prostate Centre
      • Community Research Program
      • Emergency Medicine Research Program
      • Hematology Research Program
      • Skin Research Program
      • Other Research Focus Areas
    • News and Stories
    • Researcher Directory
    • Events and Workshops
  • Research Services
    • New to VCHRI
      • Working at VCHRI
      • Regulations and Training
      • Membership with VCHRI
    • Starting Your Project
      • Research Facilitation
      • Awards and Funding
      • Grant Management
      • Operational Approval
      • CST Cerner
    • Developing Your Project
      • Clinical Trials Administration
      • Clinical Research Unit
      • Research Privacy
      • Financial Policies and Procedures
    • Additional Support
      • Education and Training
      • Communications and Branding
      • Media Relations
      • Study Recruitment Support
      • Innovation and Industry Partnership
    • Internal Awards
    • Clinical Research
    • Innovation and Partnership
  • Participate in Research
    • Reasons to Participate
    • Participant Stories
    • Find a Study
    • Recruitment Support

User menu

  • Log in

Breadcrumb

  1. Home
  2. Our Research
  3. News and Stories
  4. Discovering the likely cause of manic symptoms in bipolar disorders

Discovering the likely cause of manic symptoms in bipolar disorders

Stories Mar 31, 2023 3 minutes

Researchers have found a link between the reduced activity of a mood-regulating neurotransmitter in the brain and bipolar mania.

In a breakthrough study, researchers have identified a potential root cause of acute manic symptoms among people with bipolar disorder. Characterized by periods of extreme highs followed by long-lasting depression, bipolar disorder can have harmful effects on patients and their loved ones. 

The new study, led by Vancouver Coastal Health Research Institute researcher Dr. Lakshmi Yatham, is the first to discover a relationship between manic symptoms experienced by people with bipolar and a decrease in dopamine transporter density.

Dr. Lakshmi Yatham is a member of the Djavad Mowafaghian Centre for Brain Health, and a professor and head of the Department of Psychiatry and director of the Institute of Mental Health at the University of British Columbia.

The dopamine transporter protein is responsible for the flow of dopamine from neurons, also known as nerve cells, into the synaptic space between neurons. The released dopamine transmits signals through dopamine receptors between these neurons. 

The dopamine neurotransmitter is a hormone that supports certain motor functions in humans, as well as emotions and executive functions, such as learning, memory, mood and cognition. 

An overabundance or lack of dopamine can lead to neuropsychiatric conditions, such as mania, depression and Parkinson’s disease.

In bipolar disorder, excess dopamine has been linked to manic episodes, which can lead to feelings of euphoria, anger, irritability, extreme happiness or aggression. These may also lead to sleep loss, engagement in risky behaviours and an inability to focus or pay attention. 

“Most currently used treatments for mania reduce the function of dopamine D2 receptors,” says Yatham. “These medicines can cause a number of side effects, such as tremor, rigidity, elevation of lipids, development of diabetes and weight gain.”

“The goal is to develop bipolar treatments that specifically target the core abnormality and improve symptoms rapidly without causing significant side effects.”

Discovery opens the door to new treatments for bipolar patients with mania 

Published in JAMAPsychiatry, Yatham’s study compared the brain scans of 27 people with bipolar disorder against those of healthy controls without bipolar disorder. 

Study participants received a positron emission tomography (PET) scan, which uses a radioactive isotope to illuminate cells and their receptors in the body, and a magnetic resonance imaging (MRI) scan, which uses powerful magnets and radiofrequency waves to create three-dimensional images of tissues and bones.

The scans of bipolar patients with acute mania showed a reduction in dopamine transporter density. This reduction in transporter density occurred in the striatum — a centrally located region of the brain responsible for such behaviours as emotions, rewards, motivations and motor activity. 

“Our study showed that manic patients had lower densities of the dopamine transporter, which correlated with the severity of manic symptoms.” 

Reduced dopamine transporter density is expected to cause an excess of dopamine in the synaptic space that can lead to increased dopamine signaling and manic symptoms.

Scans of the 17 study participants with recently resolved mania and healthy controls showed relatively normal dopamine transporter density. In comparison, the scans of bipolar patients with mania had a 45 per cent reduction in dopamine transporter density on the right side of their brains and a 42 per cent reduction on the left side versus healthy participants.
 
Compared to bipolar patients with remitted mania, acute mania bipolar patients had a 40 per cent reduction in dopamine transporter density on the right side of their brains and a 37 per cent reduction on the left. 

“Assuming that an abnormality in the dopamine transporter is indeed a key driver of mania among bipolar patients, this opens up completely new possibilities for treatment.”

There is no current treatment that specifically targets the dopamine transporters to increase the uptake of dopamine from synaptic space into the pre-synaptic nerve cells. 

“The challenge now is to develop a new medication that increases the reuptake of dopamine through the dopamine transporter with an excellent safety and tolerability profile,” says Yatham.

 

Researchers

Lakshmi Yatham

Related Articles

Magic mushroom experiences among people with bipolar disorder

Eye movements could be a window into brain health and function

Brain drain: The connection between poor sleep and mild cognitive impairment

Share:

  • Facebook
  • Linkedin
  • X
  • Email

Related Research Centres/Programs

Djavad Mowafaghian Centre for Brain Health

Get the latest research headlines in your inbox

Subscribe

Recent News and Stories

Type
Stories

Cancer driver discovery opens up treatment pathways for rare pediatric disease

Sep 25, 2023 cancer, treatment options, children
Type
Stories

People in profile: Karina Thiessen

Sep 20, 2023 people feature
Type
Stories

Sniffing sleuths: Canine disease detectives

Sep 9, 2023 innovation, COVID
See more news

Get updates!

Join our newsletter mailing list to stay up to date on features and releases.

Subscribe

Quick Links

  • News and Stories
  • Careers
  • Events
  • Media Enquiries

Follow Us

  • X
  • LinkedIn

© 2023 VCHRI. All rights reserved.

  • Contact
  • Privacy Policy