The levels of are low in many people with depression and those with eating disorders. gaba serotonin dopamine norepinephrine

serotonin - Serotonin is responsible for regulating mood, anxiety, body temperature, sleep, libido as well as appetite. If proper amounts of serotonin circulate the body, then the body is relaxed and comfortable. Stress causes reduction in serotonin levels in the body, as it gets used up in trying to calm the body. Low amount of serotonin in the body can cause depression, anxiety, migraines as well as loss of appetite. On the other hand, too much serotonin in the body is also harmful and can cause Serotonin Syndrome, which can be fatal.

White dwarf is very hot, but also very small and that is why it may appear dim.