Seasonal affective disorder, also known as seasonal depression, causes depressive symptoms during only certain times of the year... and there's a pattern to it?!
Symptoms are the opposite: increased 
appetite, oversleeping, etc.
Die Symptome sind das Gegenteil:
erhöhter Appetit, Verschlafen, etc.
Los síntomas son los contrarios: 
aumento de apetito y exceso de sueño.
Los síntomas son los contrarios: 
aumento de apetito y exceso de sueño.
Par opposition, il y a augmentation
de l’appétit et hypersomnie.
I sintomi sono gli opposti: 
aumenta l'appetito e si dorme troppo.
Os sintomas são opostos: apetite e muito sono.