Answer:

senioritis

Answer	Crossword Clue
SENIORITIS	Cause of teen torpor
SENIORITIS	High school grad-to-be's "illness"
SENIORITIS	Almost-grad's "disease"

SENIORITIS	High-class affliction?
SENIORITIS	Cause of slacking off at school
SENIORITIS	Malady that typically worsens in the spring
SENIORITIS	Certain drop in motivation