What are the ways that people tell the difference between kleine levin syndrome and cronic depression?

Different Patterns: Kleine levin is rare cyclical disorder, often in adolescent males. Unlike depression, patients may be fine for long periods & then have days or weeks of prolonged sleepiness (> 20 hours in day), sudden increase ravenous appetite. Unlike depression, there is confusion & sometimes hallucinations. Brain abnormality of hypothalamus & thalamus. No response to antidepressants. May improve w/ age.