Yes, it is okay for Christians to use psychiatric medications also known as psychotropic medicines. These are medicines meant to correct chemical imbalances in the brain. Since the brain is a physical organ, it can have physical deformities. We see deformities manifest in people such as bad eyesight, limbs that are not forming properly, hearing problems, diabetes, etc. We have no problem going to doctors to help us correct such things. But if we can do that with those physical ailments, why not go to doctors that can correct chemical imbalances in the brain with medications?
Now, we have to be careful with the use of medications because sometimes people become dependent upon them when they really should not be. Also, people should not be taking medications when the real problem is that they are disobeying God's Word and are creating problems. Not all behavior problems are physically related. There can be sinful patterns learned by people. Take pornography as an example. By watching it over and over, the brain becomes hardwired to desire it. The issue here is not a biochemical problem to be corrected with medication. The issue is bad behavior that needs to be stopped, so the brain can rewire itself not to desire it anymore.
It is not within the scope of this short article to go through all the elements, both pros and cons, that deal with psychiatric medications. They have been and are still being misused. Also, it has become much easier to cover a symptom with a drug than to fix the real problem. But the truth is that the brain works by chemical interaction, and sometimes the production of those chemicals is not properly manifested due to a defect in the body. If a proper diagnosis can be reached for a person who has a legitimate physical problem in the brain and if a medication can correct that problem, there is no reason not to partake of such medications.