King Saul had a number of problems. King Saul started out as a wise, superior leader who started to show unstable thinking over a period of time, due to a number of unfortunate encounters in his life.
Saul showed that he possessed several symptoms of manic depression, clinical anxiety, and later on showed to be suicidal.
Symptoms for manic depression: increased energy, activity, & restlessness, little sleep needed, jumping from one idea to another, denial that anything is wrong, extreme irritability, and lasting sad, anxious moods. Saul expressed many of these symptoms throughout decisions he made. The never ending competition he had with David only added to the stress and overall insanity Saul expressed.
Symptoms of clinical anxiety: chronic, intense, or pathological anxiety which causes irrational outcomes. Often times anxiety can be good for people. It causes them to stay focused and alert. But when anxiety is a common daily occurrence it is far from a good thing. Saul experienced anxiety in several situations. During the wars, Saul had to lead his army and throughout a significant span of his life he has to compete with David.
Both of these illnesses became deadly for Saul. He asked his armor-bearer to let him run into his sword and his armor-bearer would not allow it. So Saul fell on his sword and killed himself.
Saul gives us a clear example of how he was born normally and certain situations he experienced made him go insane.