Manic Depression?

Kenneth Brannagh certainly brought Hamlet to life. So much so that he has me thinking more about the nature of Hamlet's illness than before we started watching the movie. We all know Hamlet is suicidal, depressed - but what what type of depression plagues him so? "That is the question." There are many different types of depression. One type in particular, manic depression (also known as bipolar disorder), could apply to Hamlet. Some symptoms or indicators of bipolar disorder include high energy, loss of touch with reality, slowness in activity (he took a while to enact his plan for revenge ), frenzied speaking, irritability, risk taking behavior, disorganized behavior, aggression, agitation, crying, hyperactivity, impulsivity, restlessness, self-harm, unwanted thoughts, delusions, lack of concentration, false belief of superiority, depression (duh), manic episodes, agitated depression, and paranoia. Maybe I'm overthinking the diagnostics; after all, we don't know if he was born with it (I don't think he was) or if this was a manifestation of his father's murder (probably). Understandably, anyone could go crazy after experiencing such a loss. 
There was little to no information about mental illness in Shakespeare's lifetime, but his play definitely made an impact on how some people think of depression today. And I don't think Hamlet's state of mind entirely directed his prognosis. I think it was a combination of his mental instability and his surroundings.