Assalamu alaikum wa rehmatullahi wa barakatuh
Have you not considered those who left their homes in many thousands, fearing death? Allah said to them, “Die”; then He restored them to life. And Allah is full of bounty to the people, but most of the people do not show gratitude.(2:243) .
According to wikipedia
Exposure therapy is a technique in behavior therapy intended to treat anxiety disorders. It involves the exposure of the patient to the feared object or context without any danger, in order to overcome their anxiety.Procedurally it is similar to the fear extinction paradigm in rodent work. Numerous studies have demonstrated its effectiveness in the treatment of anxiety disorders such as PTSD and specific phobias.
Now see the verse again.The fear of death was controlled by exposing those people to death and then their lives were restored again.Though this was not a conventional therapy but the best strategy to control fears is mentioned in the verse.