A sedentary lifestyle can affect the mood and mental health of a person. It can reduce the production and release of neurotransmitters, such as serotonin, dopamine, and endorphins, which can regulate the mood, motivation, and pleasure. It can also increase the levels of cortisol, a stress hormone, which can affect the sleep, appetite, and memory. A sedentary lifestyle can increase the risk of depression, anxiety, and other mental disorders.