The largest genetic study on anxiety disorders to date reveals new biological mechanisms behind anxiety. It can help to find new ways to develop more precise therapies.
Around one in four people suffer from an anxiety disorder at some point in their lives. These include:
--panic disorder with sudden, severe anxiety attacks,
--generalised anxiety disorder, in which sufferers worry about everyday things over a longer period of time that is difficult to control, and
--phobias of specific objects or situations.
Despite their widespread prevalence, the biological basis of anxiety is still poorly understood.
More light is now being shed on the subject by an international research team that has conducted the largest genetic study on anxiety disorders to date. The results have been published in the scientific journal Nature Genetics; the University Medical Centre Würzburg played a key role in the study.
Many genetic variants play a role
The study shows: Anxiety disorders are not caused by a single "anxiety gene". Instead, there are 58 genetic variants in the entire genome, each of which makes a small contribution to the disease. This pattern is also known from depression and other complex mental illnesses.
The researchers found strong genetic overlaps between anxiety disorders and related disorders and traits such as depression, neuroticism, post-traumatic stress disorder and suicide attempts. This may be one reason why these disorders often occur together.
Professor Thalia Eley from King's College London said: "At a time when anxiety is rapidly increasing in young people, it is crucial to deepen our understanding of what makes people biologically vulnerable. I hope that, in time, data like this can help identify people who are particularly vulnerable so that we can intervene early."
Clues to previously unknown signalling pathways
According to the study, genes involved in so-called GABAergic signalling are involved in anxiety disorders. This is an important system that regulates brain activity. The GABA molecule is already the target of several anti-anxiety drugs.
The results do not speak in favour of using genetic tests to diagnose anxiety. But identifying specific genes and biological signalling pathways that contribute to mental health problems could help to better understand how anxiety develops. Ultimately, this could lead to new treatment methods or the improvement of existing therapies.
Professor Jürgen Deckert from the University Medical Centre Würzburg: "The results provide evidence for the role of a number of previously unknown molecular signalling pathways in the aetiology of anxiety that go beyond the GABAergic signalling pathway. They form the basis for future studies in cell cultures, animal models and in humans, which will contribute to a better understanding of the neurobiology of anxiety and thus to innovative and individualised therapies."
Facts about the study
The study was based on genetic data from 36 independent samples of more than 120,000 people diagnosed with anxiety disorders and almost 730,000 people without anxiety disorders.
The study was conducted by an international team led by researchers from Texas A&M University (USA), Dalhousie University (Canada), King's College (UK), the University Hospital of Würzburg and the University of Würzburg.
