TUESDAY, Oct. 9, 2012 (HealthDay News) -- Researchers have identified a genetic mutation that is linked to mental illness and obesity.
The researchers found that deletion of brain-derived neurotrophic factor (BDNF) is associated with anxiety, depression and obesity. BDNF is a nervous system growth factor that plays an important role in brain development.
The study screened more than 65,000 people in the United States, Canada and Europe. Overall, five people had BDNF deletions. All of them were obese, had mild to moderate intellectual impairment and had a mood disorder.
Children with BDNF deletions had anxiety disorders, aggression disorders or attention deficit-hyperactivity disorder, while others with BDNF deletions had anxiety and major depression.
Those with BDNF deletions gradually gained weight as they aged, which suggests that obesity is a long-term process when BDNF is deleted, said Carl Ernst, a professor in the department of psychiatry at McGill University in Montreal, and colleagues.
"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 genetic causes of these types of disorders," Ernst said in a university news release. "Our study conclusively links a single region of the genome to mood and anxiety."
The study appeared Oct. 8 in the journal Archives of General Psychiatry. Although the researchers found an association between BDNF deletion and obesity and mental illnesses, they did not establish a cause-and-effect relationship.
The National Alliance on Mental Illness has more about mental illness.