What are the causes of generalised anxiety disorder (GAD)?
Everyone experiences worry at one time or another, but for the one in 25 people in Britain who suffer from generalised anxiety disorder (GAD), that worry becomes a chronic and unshakeable one. It often has no discernible triggers and often leaves sufferers unable to relax or sleep and with a number of associated physical symptoms such as sweating and rapid heartbeat.
GAD develops gradually, the greatest risk occurring in the years between childhood and the thirties. Its causes are complex and varied and are not yet fully understood. Complicating the issue further is the fact that there is sometimes no apparent reason for the onset.
Factors involved in GAD
Although research into GAD has not yet been able to pinpoint an exact cause of the problem, it has suggested that a number of factors might be involved:
- Genetics – researchers estimate that if you have a close relative with GAD then you are around five times more likely to develop the condition than someone with no family history of GAD. Also, according to the Anxiety Disorders Association of America, more than 5% of people will develop GAD sometime in their lives due to biological factors and their family background and experiences.
- A traumatic past – if you have suffered traumatic or stressful experiences like bullying, physical abuse or domestic violence, you are more likely to develop GAD.
- Drug or alcohol abuse – as is the case for many mental illnesses, a history of drug or alcohol abuse increases susceptibility to problems.
- A long-term painful illness or distressing condition – if you have suffered from a painful illness like arthritis for an extended period then you are more likely to develop GAD. Other health conditions can also lead to the onset of GAD. These include heart disease, menopause, gastro-oesophageal reflex disease and both hyper- and hypo-thyroidism.
- Abnormal activity within the brain is also a factor in the development of GAD.
- Learning – children sometimes develop GAD if they grow up in a home where an adult has GAD and/or significant adults constantly exhibit fear or distress. In other words, it can be a learned behaviour.
It is thought that the brain has a significant role to play in GAD. Over-activity of those parts of the brain that handle emotions and behaviour and naturally occurring chemicals associated with the control of mood are both possibly involved.
Given that anxiety and fear are closely related, researchers are examining how those parts of the brain that deal with fear function. They have found that there exists an interlocking network of brain structures that interact with each other and are responsible for the emotions associated with anxiety.
One area in particular, the amygdala, is the focus of a good deal of research. Simply put, the amygdala is part of the limbic system and appears to play a major role in the processing of the emotions. It is suspected abnormal functioning of the amygdala is linked to conditions like GAD.
The effects of stress
Increased stress can bring on GAD. This need not only be stress caused by traumatic events such as a death in the family, divorce or financial worries but can also be the stress associated with an upcoming wedding or important function. Stress, however, is not thought to be a cause of GAD; rather, it is merely a trigger.