Someone who is sober is intoxication-free, not drunk. But does being sober or having a sober lifestyle require continuous abstinence from alcohol? Yes, at least according to the standard medical definition of sobriety, a common view shared by popular recovery programs such as Alcoholics Anonymous. In a treatment setting, sobriety is the achieved goal of independence from alcohol consumption. As such, sustained abstinence is a prerequisite for sobriety.
At the beginning of abstinence, the residual effects of drinking alcohol can prevent sobriety. These effects are called PAWS or post-acute withdrawal syndrome. Someone who abstains, but has a latent desire to resume use, is called a dry drunk and is not considered truly sober. A person who abstains may be unconsciously motivated to resume alcohol consumption, but for a variety of reasons, abstain (for example, because of a medical or legal concern that prevents alcohol consumption).
Sobriety means not being under the influence of a substance. However, the word is often used in different ways in different contexts. Many 12-step programs suggest that sobriety means total abstinence and never using the substance again. For most people, the word “sober” means anyone who isn't intoxicated.
In recovery, however, sobriety has a much fuller definition. Sobriety isn't just about abstaining from drugs and alcohol. It's about moving toward complete physical, emotional, mental and spiritual health. Sobriety actually means, first, not being intoxicated.
It doesn't mean abstinence, as AA understands it to mean. In fact, the DSM psychiatric handbook (unknowingly virtually everyone who uses it, even the experts who write about it) does not contain any abstinence criteria for recovery (actually called remission). Addiction and remission have to do with no problems using or not using a substance.