1. What is the brain's role in mental health and illness?
2. How does stress affect health?
3. What are the main sources of stress and the
main approaches to managing stress?

1. Most scientists believe that mental illnesses result from problems with the communication between neurons in the brain (neurotransmission). For example, the level of the neurotransmitter serotonin is lower in individuals who have depression. This finding led to the development of certain medications for the illness.

a lack of sleep can affect body weight. two hormones in the body, leptin and ghrelin, control feelings of hunger and satiety, or fullness.

explanation: