Anxiety: from genes to behaviour
anxiety, stress, epigenetics
Anxiety disorders are among the most prevalent psychiatric disorders presenting high comorbidity with other disorders such as depression and substance abuse. Having a complex etiology, anxiety is often linked to stress, so that a significant parcel of initial studies was dedicated to investigate alterations in the hypothalamus-pituitary-adrenal axis. More recently, with the advance of molecular biology techniques, new possibilities may arrive in the field of anxiety disorders. Twin-pair research has shown that anxiety disorders are moderately hereditary. However, genetic association studies (GWA) failed to identify genes significantly associated with the diagnosis. These results show the importance of environment as well as the asscociated epigenetic factors for the development of the disorders. Complete epigenome association (EWA) studies have shown changes in DNA methylation in patients with anxiety disorders. |Conversely, experiments with laboratory animals aimed to detect epigenetic changes that could be linked to abnormal behaviors in those animals. In fact, several evidences in literature point to the possibility of maintaining epigenetic alterations through different generations and it would be related to the behavioral changes in offspring. Thus, neuroepigenetics may help explaining the individual variations regarding susceptibility to environmental stress, as well as help determine anxiety-related markers that may become targets for future treatments.