Anxiety disorders are a considerable global concern. Affecting almost 1 in 5 adults, they can significantly impact an individual’s quality of life. Characterised by intense feelings of worry, anxiety disorders can also produce physical symptoms, such as an increased heart rate and shaking.
As with many disorders of the mind, little is known about the nuts and bolts — for example, which cells, regions, and pathways are to blame. Because of this, medications tend to attack the symptoms rather than the source of the issue.
Now, thanks to a brand new review published in the Journal of Psychopharmacology, a new discovery has been found where researchers discovered that there were more than eight million cases of anxiety in the UK in 2010. (The overall UK population is estimated to be 66 million, according to the Office for National Statistics.) As the NHS states, there are a number of anxiety disorders. Generalised anxiety disorder (GAD) affects up to five percent of the UK population. Other conditions that fall into the anxiety bracket are panic disorder, obsessive compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and phobias.
A variety of factors are thought to play a role in the development of GAD, including an imbalance of mood-regulating chemicals, overactivity in certain areas of the brain, traumatic experiences, and genes inherited from parents. According to the NHS, a person can be five times more likely to develop the disorder if they have a close relative with the condition. There also appears to be a familial link with OCD development.
Interestingly enough, experts on the matter also believe that a combination of biological and environmental factors contribute to the onset of anxiety. According to David Veale, a Consultant psychiatrist and visiting professor at King’s College London’s psychology department “anxiety disorders are about 40 percent hereditary.” The rest, he says, is “linked to the environment.”
“Genetic factors are probably important in the personality dimension of anxiety-proneness (sometimes called ‘neuroticism’) which places people at higher risk of various anxiety disorders,” says David Baldwin, professor of psychiatry and head of mental health at the University of Southampton’s faculty of medicine. “This may explain why a family might have members with differing conditions such as panic disorder and obsessive compulsive disorder.”
But Baldwin, who is also a clinical advisor for the Anxiety UK charity, adds that other causes of anxiety in later life “such as adverse experiences in childhood and adolescence” are also important. “In most patients, a range of familial, developmental, and environmental factors have contributed to anxiety,” he concluded.
According to another study, researchers from the University of Wisconsin School of Medicine and Public Health in Madison investigated anxiety in a population of almost 400 rhesus monkeys. Using MRI scanning technology, they shine a light on the dimly lit pathways involved in anxiety. Their results were published recently in the journal J Neurosci.
To investigate further, the researchers first assessed each young primate’s natural anxiety level by exposing them to a human intruder and noting their behaviour — more anxious individuals moved around less and made fewer vocalisations. The scientists also measured cortisol levels as a measure of stress.
As expected, monkeys with higher levels of anxiety were found to have increased activity in the Ce and BST. The animals used in the study came from the same pedigree and were, therefore, all related to different degrees. Because their breeding had been carefully documented, the investigators knew who was related to whom and how closely. This allowed the team to calculate how heritable anxiety is and whether the heritability matches up with changes in brain activity.
They found that the levels of connectivity between the Ce and BST were, indeed, strongly heritable; as the authors explained “In the current study, co-heritability analyses demonstrated that Ce-BST functional connectivity and anxious temperament are passed down the family tree together, supporting the hypothesis that Ce-BST functional connectivity and anxious temperament share molecular underpinnings.”
Figuring out how genetic (and potentially hereditary) aspects react with the environment to form an anxiety disorder is the focus of a huge new study. Genetic Links to Anxiety and Depression (GLAD) aims to recruit 40,000 people across the UK who have been diagnosed with anxiety or depression. Experts hope to find genetic causes and to use these causes to develop more effective treatment