Is it possible to use metal illness as a defense to a criminal charge?

The short answer is yes, using mental illness reasons as a defense in a crime is allowable. However, it is not a complete defense that will make any punishment disappear. Using mental illness reasons as a defense in a crime is typically a mitigating factor, which means it can help explain what you did or perhaps show that you were not capable of controlling or understanding your actions. The danger in using this defense is that it can often carry as punishment a required commitment to a mental hospital for treatment and/or required treatment programs that may last longer than a regular jail sentence would carry. Before committing to any mental illness defense, you should speak with an experienced lawyer to understand the benefits and risks of your decision.