. A person may choose to self-medicate if they are not aware that they have the disease or even after being diagnosed during the times of their episodes they may have found something to help them get past the episode at that time. For instance since people with schizophrenia may suffer from hallucinations, bad thoughts, anxiety, paranoia symptoms. They may take a illegal drug that they believe may help them silence voices, bad thoughts, while allowing them to relax, sleep and alleviate some of those symptoms. So when they are diagnosed and given medication to take for their symptoms, their is a good chance they self-medication may cause their proper treatment to be less effective. Or if they have become addicted to self-medicating if they continue to do so while taking their prescription medication it can reduce the effectiveness of the prescribed medicine.
