What happens when no amount of exposure with positive or neutral outcomes can result in habituation? This level of unwarranted fear is known as a phobia, a very strong and overpowering fearful response (terror) that cannot be diminished, even through repeated exposure to the stimulus in the absence of negative consequences.
Even when the individual is aware of the innocuousness of said stimulus, they cannot but react with intense fear. Many people with a phobia aren’t comfortable even looking at a picture of the object of their phobia, yet they are fully aware of the fact that it is nothing but an image.
What causes the development of phobias is unclear. Some attribute it to lesions or trauma to the regions of the brain responsible for fear responses, traumatic experiences (although this has been repeatedly disproven) and predisposing genetic factors.
When a phobia greatly diminishes the affected individual’s quality of life, oftentimes medication is the most effective option.