Substance use disorder occurs when a person needs alcohol or another substance (drug) to function normally. Abruptly stopping the substance leads to withdrawal symptoms. Addiction means that a person has a strong urge to use the substance and cannot stop, even if they want to.
So it is important to maintain positive nitrogen balance in the body while sleeping. When you do and conditions are right so that your rate of protein synthesis exceeds your rate of degradation, and you maintain a positive nitrogen balance, you can grow while you sleep.
Others always tend to be on the low end of the spectrum of sleep needs. Your baby won't even begin to develop a circadian rhythm until she's about six to nine weeks old, and that rhythm doesn't mature until she's at least six months old. Babies will wake up and sleep often because they are made to do so.