Depression is a medical illness that causes extreme feelings of sadness, loss of interest and can cause physical symptoms, too.  Depression isn't something that you can simply sleep off or snap out of.  Wendy Linderholm, PsyD, a licensed clinical health psychologist and the Director of Behavioral Health at MemorialCare Medical Group, is committed to working in the medical community with all its participants; from patients/families, to staff and physicians. Wendy Linderholm, PsyD explains the common causes, symptoms and the proper treatment and tests that are used to help diagnose depression.