This character is a Sleepyhead but it's not simple quirk. They're in too much mental pain to do anything but sleep. Maybe they've suffered a recent tragedy or maybe they suffer from (often untreated) mental illness, but this character spends a lot of time sleeping. There are also those who use sleeping, or more specifically dreaming, as escapism from their waking stress.
There is Truth in Television to this. A common symptom of several mental illnesses, including clinical depression, is lethargy and sleepiness.
Angst Coma is a more extreme version of this. Contrast with The Insomniac, who oftentimes are also depressed or otherwise not of sound mind yet have the opposite issue with sleep. Compare to Heroic Safe Mode and Asleep for Days. This trait is often seen in hikikomoris.
- It's mentioned in Blankets that the bullied and abused Craig used sleeping as escapism as a young child. Later, he turned to drawing instead.
- In The Sandman, Dream's pouch of sand ended up in the hands of John Constantine's junkie ex-girlfriend Rachel. When their relationship ended, Rachel used the sand as a drug to keep herself asleep all the time in order to cope with her depression. The effects of years of inactivity upon her already-unhealthy body are not pretty, and Dream ends up putting her in a permanent sleep in order to spare her from the suffering that withdrawal would have brought.
- In Her Fractured Spirit, a sign of Callie's worsening depression is that she stays in bed all day.
- Weight of the World: As Alfred's depression and PTSD worsens, he spends days in bed and alternates between laying awake for hours and sleeping all day. One day he gets out of bed for only twenty minutes. He spends those minutes in an apathetic, exhausted haze before he mumbles that he's too tired and returns to bed. He goes back to sleep without eating or showering and feels worse because he did not accomplish anything that day. As he falls asleep, he tries and fails to reassure himself that he will feel better tomorrow. He doesn't.
- Ambitious Love: Natsuki mentions that Kumiko spent a week eating nothing but sleeping pills and ice cream after Reina abandoned her the second time. She later attempted suicide but was saved before she bled out.
- After being tortured and blinded in Jack O'Lantern, Sarada finds that she enjoys sleeping more than she did before. This is because at least in her dreams she can still see. This is also why she rejects her sleeping pills; she finds even nightmares better than dreamless slumber.
- In Epica's "Mother Of Light (A New Age Dawns Part II)", sleeping as a form of escapism is mentioned:
Reality is sometimes stranger than fictionWhatever happens in my dreams—I know it can't be worse than thisSo I prefer to sleep
- Doki Doki Literature Club!: One of the first things we learn about Sayori is that she is prone to sleeping late and being late to school. This seems at first just to be a side-effect of her flighty nature, but then it's revealed that she's had horrible depression her entire life, and she sleeps a lot because of that.