The best treatment for claustrophobia is CBT (cognitive behavioral therapy). Much of the work in CBT is addressing your irrational thinking and exposing yourself gradually to your fears, instead of avoiding the feared stimulus altogether.
Medication treatment for claustrophobia is only an adjunct to CBT and exposure work. Benzodiazepines can be prescribed on a short term basis to address any phobic anxiety that may arise during the exposure sessions.
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