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?!
Seasonal affective disorder 
is, as the name suggests,
Wie der Name schon sagt,
El desorden afectivo estacional 
es, como dice el nombre,
El desorden afectivo estacional es, 
como dice el nombre,
Le trouble affectif saisonnier,
Si parla di disordine affettivo stagionale
Transtorno afetivo sazonal, como o nome sugere,