Depression is associated with many other disorders, such as OCD, Generalized Anxiety Disorder, and Post-Traumatic Stress Disorder. Although the term “depression” is used often colloquially to describe how one feels on an “off” day or after a bad break-up, clinical depression can be quite devastating. Persistent sadness, excessive feelings of guilt, and changes in weight are common, as well as poor sleep, thoughts of suicide, and fatigue. Depression takes away the sufferer’s energy and motivation, making it difficult to succeed in treatment for other associated disorders if the depression is not also addressed. Cognitive-Behavioral Therapy is successful in treating many people with depression, and involves examining and replacing unhelpful belief systems that perpetuate the sufferer’s symptoms.