“Major depression cripples millions of people and, within a decade, is likely to be the second leading cause of global medical disability.”
Stress is often the cause of major depression. Depressed people have an inability to feel pleasure. This ability is tied to the neurotransmitter called dopamine in a brain area called the nucleus accumbens. The effects of stress hormones called glucocorticoids flips a switch in the brain and stimuli that would normally create motivation, a sense of curiosity and reward evoke the opposite.
Affirmation: Joy is in me. I can go to that place at all times.
For more on research in rats, click on the link below.