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About Major Depressive Disorder (MDD)

Depression is a medical illness that affects how a person feels, thinks, and acts. It may cause persistent feelings of sadness and can also cause a lack or loss of interest in things a person used to enjoy. People with depression may have trouble doing normal day-to-day activities, and this can lead to a decrease in their ability to function at work or home. While depression is treatable, it is not something someone can easily “snap out of.” Additionally, depression is different from the typical sadness felt from difficult experiences such as the loss of a job or the death of a loved one.Footnote1

There are several risk factors that may play a role in the development of depression. These include:


Certain chemicals in the brain may contribute to the development of depression.


Depression may run in families.


People who have low self-esteem or are easily overwhelmed by stress may be more likely to develop depression.

Environmental factors

People who are continuously exposed to neglect, abuse, violence, or poverty may be more vulnerable to developing depression.Footnote1

Depression may be categorized as mild, moderate, or severe (also called “major”). The classification depends on many factors, including the symptoms being experienced, their severity, and how often they occur. Those with major depression experience depression most of the day, nearly every day, for at least 2 weeks.Footnote2

Just like the symptoms vary from mild to severe, the same treatments do not work for everyone. Some people still experience a lack or loss of interest in usually pleasurable activities on their current antidepressant medication(s) while others have trouble finding an antidepressant medication that works for them. Clinical research studies such as the TERPSIS and SAVITRI Studies are important in the search for potential future treatment options that may address these unmet needs for people with MDD.

Participants in the TERPSIS and SAVITRI Studies could make a difference in the lives of others with major depressive disorder. If you’re interested in joining the TERPSIS or SAVITRI Study, we invite you to click the button below to answer some questions about yourself and see if you may qualify.

See if you may qualify