Alcohol-Induced Blackouts

How Drinking Too Much Can Cause Lost Memories


Binge drinking or consuming large amounts of alcohol in a short period of time can cause an alcohol-induced blackout. According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), alcohol-induced blackouts “are gaps in a person’s memory for events that occurred while they were intoxicated.” 

Consuming too much alcohol can prevent the hippocampus from consolidating memories. Alcohol effectively blocks the transfer of memories stopping them from being carried over to long-term storage.

Fragmentary and En Bloc Blackouts

There are two different types of alcohol-related blackouts. The first is a “fragmentary blackout” where memories are fragmented by “missing periods of time.” The second type of blackout is an “en bloc” blackout where no memory of an event is stored. The memory cannot be recovered and is completely unavailable. 

Blackouts and Blood Alcohol Concentration

High blood alcohol levels, such as .16% and higher, make it more likely that a person will experience a blackout. However, it is not uncommon for alcohol-related blackouts to occur at lower blood alcohol concentration levels, particularly when alcohol is mixed with over-the-counter or prescription medication. 

The Danger of Blackouts

Blackouts can be extremely dangerous. Alcohol-related blackouts can have several repercussions and may lead to unintended consequences. It is important to seek treatment if you are experiencing multiple periods of memory loss or complete (en bloc) blackouts. If you are unable to stop drinking despite wanting to, you should consider treatment. There are numerous options for individuals with a reliance on alcohol, alcohol addiction, or alcohol use disorder.