As someone said it best on Ars yesterday, depression is not a get out of prosecution free card.
According to the documents, Swartz downloaded more than two million JSTOR documents over a two-week period by using a variety of deliberate, evasive tactics designed to confound JSTOR controls.
He knew what he was doing. He wanted to play Robin Hood but forgot that Robin Hood had a death sentence on him for his actions. Rightly or wrongly so, you do the crime and you're looking at doing time.