This lesson will explain how psychological defense mechanisms are utilized in different situations. It is 1 of 5 in the series titled "Psychological Defenses."

This lesson will identify, describe and differentiate the primary symptom(s) for situational depressive disorders.

Understand the biology of depressive disorder. [9:02]

Depression is the number one reason people seek mental health services. This video looks at biological factors, psychological factors, and environmental factors involved in depression. [11:17]

In times of need, your social network can provide social support in a multitude of ways. This video explains four main types of social support that we can provide for each other. [3:36]

Visit us (http://www.khanacademy.org/science/healthcare-and-medicine) for health and medicine content or (http://www.khanacademy.org/test-prep/mcat) for MCAT related content. These videos do not provide medical advice and are for...

This video discusses the pros and cons of five types of therapy for depression: cognitive therapy, behavioral therapy, cognitive behavioral therapy, interpersonal therapy, and psychodynamic therapy. [8:12]

Find out about studies of the drug Ketamine, and how it affects the brain and depression.

Psychiatrist Richard A. Friedman discusses several effective treatments for the winter blues.

Dr. Andrew Weil discusses antidepressant alternatives in his book Spontaneous Happiness.

The concept of an angle of depression is discussed here. This lesson is 2 of 5 in the series titled "Angle of Depression."