The real cause of SADness

Scientists appear to have found proof that serotonin regulation is key to why some people suffer from seasonal affective disorder (SAD).

In their study of 11 SAD patients and 23 healthy controls they found significant summer to winter differences in the levels of the serotonin transporter (SERT) protein.

They found SAD patients had higher levels of SERT in the winter months, corresponding to a greater removal of serotonin in winter, according to a presentation at the European Congress of Neuropsychopharmacology in Berlin in late October,