Study links deletion of brain-derived neurotrophic factor to major depression, anxiety, and obesity

October 8, 2012

McGill researchers have identified a small region in the genome that conclusively plays a role in the development of psychiatric disease and obesity. The key lies in the genomic deletion of brain-derived neurotrophic factor, or BDNF, a nervous system growth factor that plays a critical role in brain development.

To determine the role of BDNF in humans, Prof. Carl Ernst, from McGill's Department of Psychiatry, Faculty of Medicine, screened over 35,000 people referred for at clinics and over 30,000 control subjects in Canada, the U.S., and Europe. Overall, five individuals were identified with BDNF deletions, all of whom were obese, had a mild-moderate intellectual impairment, and had a mood disorder. Children had , aggressive disorders, or attention deficit-hyperactivity disorder (ADHD), while post-pubescent subjects had and major depressive disorders. Subjects gradually gained weight as they aged, suggesting that obesity is a long-term process when BDNF is deleted.

"Scientists have been trying to find a region of the genome which plays a role in human psychopathology, searching for answers anywhere in our DNA that may give us a clue to the of these types of disorders," says Prof. Ernst, who is also a researcher at the Douglas Mental Health University Institute. "Our study conclusively links a single region of the genome to mood and anxiety."

The findings, published in the , reveal for the first time the link between BDNF deletion, cognition, and weight gain in humans. BDNF has been suspected to have many functions in the brain based on animal studies, but no study had shown what happens when BDNF is missing from the . This research provides a step toward better understanding human behaviour and mood by clearly identifying genes that may be involved in mental disorders.

"Mood and anxiety can be seen like a house of cards. In this case, the walls of the house represent the myriad of biological interactions that maintain the structure," says Ernst, "Studying these moving parts can be tricky, so teasing apart even a single event is important. Linking a deletion in BDNF conclusively to mood and anxiety really tells us that it is possible to dissect the biological pathways involved in determining how we feel and act.

We now have a molecular pathway we are confident is involved in psychopathology," adds Ernst, "Because thousands of genes are involved in mood, anxiety, or obesity, it allows us to root our studies on a solid foundation. All of the participants in our study had mild-moderate intellectual disability, but most people with these cognitive problems do not have psychiatric problems – so what is it about deletion of BDNF that affects mood? My hope now is to test the hypothesis that boosting BDNF in people with anxiety or depression might improve brain health."

Explore further: Scientists find molecular evidence of brain changes in depressed females

Related Stories

Scientists find molecular evidence of brain changes in depressed females

September 16, 2011
Researchers at the University of Pittsburgh School of Medicine have discovered molecular-level changes in the brains of women with major depressive disorder that link two hypotheses of the biological mechanisms that lead ...

CAMH study confirms genetic link to suicidal behavior

October 7, 2011
A new study from the Centre for Addiction and Mental Health has found evidence that a specific gene is linked to suicidal behaviour, adding to our knowledge of the many complex causes of suicide. This research may help doctors ...

Recommended for you

Cultural values can be a strong predictor of alcohol consumption

November 20, 2017
Countries with populations that value autonomy and harmony tend to have higher average levels of alcohol consumption than countries with more traditional values, such as hierarchy and being part of a collective. This new ...

A walk at the mall or the park? New study shows, for moms and daughters, a walk in the park is best

November 17, 2017
Spending time together with family may help strengthen the family bond, but new research from the University of Illinois shows that specifically spending time outside in nature—even just a 20-minute walk—together can ...

Risk of distracted driving predicted by age, gender, personality and driving frequency

November 17, 2017
New research identifies age, gender, personality and how often people drive as potential risk factors for becoming distracted while driving. Young men, extroverted or neurotic people, and people who drive more often were ...

When male voles drink alcohol, but their partner doesn't, their relationship suffers

November 17, 2017
A study of the effect of alcohol on long-term relationships finds that when a male prairie vole has access to alcohol, but his female partner doesn't, the relationship suffers - similar to what has been observed in human ...

Spanking linked to increase in children's behavior problems

November 16, 2017
Children who have been spanked by their parents by age 5 show an increase in behavior problems at age 6 and age 8 relative to children who have never been spanked, according to new findings in Psychological Science, a journal ...

Multiplayer video games: Researchers discover link between skill and intelligence

November 15, 2017
Researchers at the University of York have discovered a link between young people's ability to perform well at two popular video games and high levels of intelligence.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.