Phobias. By: Cecilia Comber Silvana Oberti Roberto Lambertini. What is a Phobia?. A phobia, by definition, is an irrational fear of an object or a situation.
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By: Cecilia Comber
There has been evidence that phobias are sometimes common in families and that genetics may be involved in all of this. When a person is exposed to their fear or feared situation, biological changes in the body occur.
When a person is exposed to a phobia there is a change in the brain activity and certain hormones are released such as cortisol, insulin, and growth hormone. There is also an increase in physical arousal symptoms, for example increased heart rate and blood pressure.
Neurotransmitters are the biochemicals that allow nerve cells in the brain to communicate. Researchers have found out that too much or too little of this or other chemicals may create anxiety and not limit the body’s reaction to fear.
The amygdala is a nuclear complex located in the dorsomedial portion of the temporal lobe. A part of the amygdala known as the lateral nucleus is responsible for fear responses. There are many more circuits leading from the amygdala to the prefrontal cortex than vice versa. This causes humans to have little control over their fears.
Damage to the hypothalamus may also be the cause of phobias. This can be seen in phobic children, for example, as they are born with a decrease in the neuron activity in the amygdala and hypothalamus. The hippocampus has to do with memory, so damage to it could cause someone to incorrectly remember an event which was fearful to them. The medial prefrontal cortex creates extinction, which weakens a fear response to a conditioned stimulus over time. So damage here allows a fear response to stay there for years after the first encounter with the stimulus.
Some of the people with agoraphobia have a mild heart condition known as mitral valve prolapse, which causes heart palpitations that might cause panic attacks.
Genetics play an important role when it comes to the formation of phobias. There has been some investigation regarding hereditary phobias but more recently there has been evidence that phobias may be related to a mutation in chromosome 15. People with this mutation are born with it but it doesn’t show up until later in life.
There has not been much research done regarding biological treatments for phobias and many psyhologists belive that there are better ways of treating phobias, but recently this has changed.
Scientists are now giving their patients with phobias selective serotonin reuptake inhibitors like paroxetine or antianxiety medications such as diazepam.
Some drugs such as Xanax and Valium are used in short-term situations. Beta-blockers are also sometimes given lessen the fear response.
Antidepressants are also prescribed sometimes because is has been proven to be helpful in preventing panic attacks that take part in phobias such as agoraphobia. This way, the patients can deal with the problem itself without having to deal with the panic attacks that come from it.
All the drug treatments cause a decreased blood flow in the amygdala and hippocampus, just as some other forms of phobia treatments do.
The biological treatments are sometimes not recommended for long-term use because it is said to cause little benefit with long term use, unlike with some of the other perspectives.