Complex sentence: The "Soprano temper" becomes the focus of Tony's next session with Dr. Melfi, who observes that depression and anger are traits in Tony's family and that depression can be a manifestation of rage turned inward.
Split into simpler sentences: The "Soprano temper" becomes the focus of Tony's next session with Dr. Melfi. She observes that depression and anger are Soprano family traits and that depression can be a manifestation of rage turned inward.