Will my targeted client benefit from taking medication for his delusions?

You are in an awkward situation being asked about a medical consideration here, and this we understand. We can tell you that he will not benefit from taking medication. It will create a series of complications of its own. There will be times when he is placated through having a numbing of the mind and this could be seen as respite from his issues, and that would be helpful with sleep. But the sleep will not be truly fully restful and the medication will have consequences that will be irksome and a liability, so part of the time he will feel badly because of side effects. This is typical with antipsychotic medication. There are a few people who do just fine with no complaints, but the majority will have noticeable perturbations that are unpleasant and will affect the quality of life to some degree at least. So this is very much a trade-off. If he can get through this immediate period and have some easing of things, and weather the storm, things will get better and the need for medication can be avoided. Part of the issue is the degree to which he can be weaned from this purported healer who is hurting rather than helping, despite what the mother believes.