Short genes for greater sensitivity
In the UK, one in ten children will be affected by an anxiety disorder. There are a range of treatments available, not least of which are the ‘talking therapies’ such as cognitive behaviour therapy (CBT). A team of researchers at Kings College London have, for the first time, established a link between a child’s genes and the chances that they will benefit from CBT.
This study was carried out on a sample of around 360 children, all with anxiety disorder. Anxiety disorder is a term that covers OCD, phobias, post-traumatic stress disorder and panic attacks.
Samples of DNA were taken from each child with a specific focus on a section called the serotonin transporter promoter. Serotonin is a chemical that is used to transmit signals between nerve cells, neurons. When an electrical signal comes to the end of the neuron, serotonin is released into the synapse, or gap, between it and the next neuron. When the serotonin is absorbed by the second cell it induces an electrical signal and so the message is passed on through the nervous system.
The serotonin needs to be reabsorbed from the synapse so it can be reused by the neuron to transmit the next nerve signal. This is done with the aid of a protein, known as a serotonin transporter, that is fixed into the membrane of the nerve cell. These transporters act like gates that allow the serotonin back into the neuron.
In the mid 1990’s it was found that there are different lengths of the section of DNA used to encode for the transporter. Specifically this difference is due to the difference in length of the promoter region of the gene. The promoter is a section of DNA that helps with the creation of a protein; in this case, the transporter.
The short form of the promoter has been linked with an increased risk of anxiety disorders, but only under environmental conditions that would promote these disorders. It is this combination of the length of the promoter and the environmental factors that has caused this to be labelled the ’sensitivity gene’. Having the short form doesn’t mean a person will get an anxiety disorder, but it does mean that they will be more likely to suffer from such a disorder when placed in stressful situations.
The study at Kings College London has shown that children with the short form of the promoter are 20% more likely to respond to CBT and enjoy at least 6 months free of anxiety disorder following the treatment.
CBT focusses on the dysfunctional ideas, behaviours and emotions that an individual has. It relies on fostering a positive, secure environment where the client and the therapist work together to form solutions.
This ties in well with the idea of the short form of the gene linking with a response to the environment. In a negative environment there is a greater chance of suffering an anxiety disorder, but in a positive environment there is a greater chance of improvement.
No-one likes to see youngsters suffer and there is something pleasing about the fact that the gene that promotes anxiety disorder in children in stressful situations may also be the key to finding their way back to rude and robust mental health.
See the original article at ‘Sensitivity gene’ predicts whether anxious children will benefit from CBT