Not true. It is more important to go to bed at the same time and wake up at the same time everyday. Not everyone needs eight hours. In fact, if I get eight hours sleep I usually feel tired and groggy for the entire day.
Many drugs affect the release, arrest and efficacy of serotonin, including antidepressants, psychedelic hallucinogens, synthetic opiates, dissociatives, drugs for treating migraines, antihistamines, and stimulants such as MDMA.
Neurotransmitters usually have multiple functions, and they work together to produce certain effects. Both serotonin and norepinephrine seem to help regulate mood. An older class of antidepressants, the tricyclics, also affect serotonin and norepinephrine, along with other neurotransmitters. Most of the side effects that people experience when taking tricyclics come from the overlapping effect on other neurotransmitters, like histamine and acetylcholine.