Definition – all of the following:
(1) an inability to recall events (memory loss)
(2) did not involve a loss of consciousness
(3) that occurred during a drinking episode
The memory loss may be either:
(1) fragmented (some things remembered and other not)
(2) en bloc (everything missing)
Correlates:
(1) An episode usually occurs after heavy drinking with a rapid rise to a high blood alcohol concentration (Perry et al report that a blood alcohol concentration >= 310 g/dL is associated with a >= 50% probability of a blackout).
(2) A person with frequent blackouts is at increased risk for alcoholism.
(3) A person with blackouts is at increased risk for alcohol-related injury.
Differential diagnosis:
(1) mixed alcohol and drug abuse
(2) “being slipped a Mickey” (Rohypnol, etc)
(3) head injury
(4) “passing out” (loss of consciousness)
(5) seizure
