Blackout or Partial Amnesia after Drinking Alcohol

Affected individuals often believe they are awake in strange places without remembering how they got there. Thus, some people under this syndrome perform even criminal acts such as murder.

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The blackout syndrome is a phenomenon that is produced by an acute intoxication derived from the consumption of alcohol. It is a kind of amnesia that affects any memory that includes episodes that have occurred under the influence of alcohol.

Thus, blackout is characterized by a deterioration of memory during alcohol intoxication. Under this syndrome, affected people can behave in certain characteristic ways. One is known as the blockage, which causes people to drive long distances without being fully aware of it or to hold apparently normal conversations at parties that they may not remember.

Affected individuals often believe they are awake in strange places without remembering how they got there. Thus, some people under the influence of this syndrome are able to perform even criminal acts such as murder.

Types of blackout

A blackout can be complete (in block) or partial (fragmentary or attenuated). Thus, when a person is affected by a complete blackout he presents a total amnesia with respect to certain significant episodes that would otherwise be memorable. What most characterizes this type of blackout is that the memory loss is permanent and can not be recovered under any circumstances.

However, it seems that fragmentary blackouts occur more frequently. In this type of amnesia induced by alcohol, there are more likely to remember what happened or part of it.

In these cases, the patient may believe that he has nothing to remember, that simply those forgotten events do not exist. Thus, the metamemory deficit is a problem in research on partial blackout.


This syndrome is common especially in people who have a high volume and frequency of alcohol consumption.

In fact, this factor is the most related to the causes of blackout. Thus, nowadays it is known that anyone who drinks too much and too quickly can experience a blackout.

Risk factor’s

Although a high concentration of alcohol in blood is required to induce a blackout, many of these people who consume alcohol remember having drunk much more and not having had this type of amnesia.

Thus, it seems that the main risk factors of blackout are:

  • Drinking alcohol (usually quickly).
  • Drink on an empty stomach.
  • And drink liquor or alcohol different from beer.

However, it seems that not all those people who drink quickly and excessively present this type of episodes of amnesia. There are people who, for some reason, are more vulnerable to the deterioration of alcohol-induced memory.

Pathophysiology of blackout

A blackout is the result of the interruption of the formation of the memory induced by alcohol. The formation of memory involves the following processes:

  • Coding, initial registration and interpretation of stimuli.
  • Storage, consolidation and maintenance of encoded stimuli.
  • Recovery. That is, the search and recovery of stored stimuli.

Alcohol has its greatest effects in the first process of memory, coding. The effect of alcohol on coding may interrupt the processing of the context for the formation of episodic memory.

Episodic memory is responsible for the context of memories. If the episode is encoded with a defective context, as may occur in blackout, then the recovery of memories related to episodic memory can be particularly difficult or even impossible, in the case of total blackout.

The positive of partial blackout is that, in them, remembering a subject the events that occurred during the blackout often resuscitates some forgotten memories. These details can be beneficial to reconstruct the memory that was not well coded.

Therapeutic implications in alcohol-induced amnesia

To this day it seems clear that blackouts do not occur only in those people who abuse alcohol. However, blackout is an indication of excessive consumption of this. In fact, a large majority of alcoholics experience blackouts during the early phase of addiction.

In addition, chronic blackouts can be a clear sign of alcoholism. It has been determined in a study that the university students who presented this syndrome were scared by the amnesia they had. Therefore, his alcohol consumption decreased.

The case is that, if the behavior of alcohol consumption is not modified properly after the occurrence of this syndrome, this can lead to a chronic addiction to alcohol. Thus, learning about this situation can be key in those affected by alcohol-induced amnesia.