I was first introduced to the concept of the insanity defense as a senior in high school and when asked to take a side in a criminal case, I remember thinking that pleading insanity was absurd and giving criminals an easy way out. However, given the opportunity to reconsider I realize there is a lot more that goes into it. In fact, people who get the insanity defense often give up their freedom for longer than a prison sentence for the same crime but they are less likely to reoffend for the same crime.
In an article on insanity defense, they explain a case in which a man with no previous history of mental illness pushed a woman into the path of a subway train, he was later evaluated and found to be psychotic (Reid 171). This was an interesting case because there was no previously known illness. It brings up an interesting point in questioning how consistent this defense can be because someone like Jeffery Dahmer was found to be sane by a court of law in his trial. No two of these cases are like on another so it is hard to set certain guidelines for judges to follow in these types of cases because they are so unique and it is possible that two different juries would not vote the same on the same case.
Other difficulties with the jury include the state of the individual. It could be more convincing to a jury if they see the psychosis in a court of law, however being in a state of psychosis leads to unpredictable behavior. Taking medication controls psychosis and the unpredictable behavior but it produces side effects that make it difficult to be in court, however stopping necessary medication after it has started produces other side effects and withdrawal symptoms. No matter what the situation is riddled with ethical issues and difficult to keep consistent.
Reid, W. (2000). The insanity defense: Bad or mad or both? Journal of Psychiatric Practice, 169-172.