How long does a delusional state last?

Depends. 20 minutes to 15 years. There are many causes-- so many variations. When treated, the duration decreases.
Depends. The length of time a delusional state exists is partially related to the cause. If it is induced by a chemical or drug, the influence of that will have to wear off. If it is a result of a mental disease, the duration is not predictable unless one knows the history of the individual.

Related Questions

How long does a delusional state last from smoking pep spice? Is there anything that can enhance recovery and stabilization?

Don't know. "pep spice" is extremely dangerous -- it consists of unidentified herbs & spices sprayed with a synthetic thc-like substance in unmeasured quantity. It produces a feeling of being stoned ['delusional"]. When you don't know the particular contents or amount, you also don't know "how long" this state will last -- or how best to enhance recovery or stabilization. My best advice is to steer clear! Read more...