Final answer:
Hypersomnia is a specifier of melancholic depression, characterized by excessive sleepiness and prolonged sleep periods.
Step-by-step explanation:
One of the specifiers of melancholic depression is hypersomnia. Hypersomnia is characterized by excessive sleepiness and prolonged sleep periods. It is a common symptom of melancholic depression, where individuals may sleep for longer durations but still feel fatigued and lacking energy.
Insomnia is actually the opposite symptom, characterized by difficulty falling asleep or staying asleep. Excessive guilt is a common symptom of depression in general, but it is not specific to melancholic depression.