Potential animal models of seasonal affective disorder

▶ Depression is associated with morphological changes in the hippocampus. ▶ Seasonal Affective Disorder (SAD) involves changes in mood across a year. ▶ Some rodents undergo structural alterations in the brain depended on day length. ▶ Many rodents increase depressive-like responses after exposure to short days. ▶ Seasonal rodents may be a good model for SAD.