There is a lot of misconceptions about the term "blackout", which can occur after heavy and rapid alcohol consumption. Blackout is not automatism but is a total loss of memory from the moment of obtaining a high BAC until sometime later. This is know as anterograde amnesia. This is different from retrograde amnesia, in which the person who suffers trauma forgets the past (such as from a blow to the head). The term "blankout" would probably be a better descriptor of this phenomenon.

Ten Commandments

One of the top researchers in blackouts- Dr. D.W. Goodwin described the results of his studies as:

Our findings had legal implications. Blackouts have rarely been held in extenuation for crimes, but lawyers continually try. I receive calls; when I tell lawyers what we found, they usually do not call back. What we found was that remote memory was intact but that people had trouble with short term memory, which meant that, during a blackout, a person would be able to recite the Ten Commandments and know the consequences of robbing a bank, it was simply that he would not remember these things for 30 minutes later or the next day. He knew right from wrong at the time of the act and this appears to be the crucial fact where the law is concerned.

Dr. Goodwin also found that one could not tell by physical signs or behavior, whether a person was having a blackout or not.

Risk Factors

There are various factors that increase the risk of a blackout.

The consumption of both liquor and beer are much more frequently associated with blackouts than is beer alone

Gulping drinks, especially on an empty stomach increases the risk of a blackout

On average 10 to 14 drinks are consumed prior to a blackout

The average BAC at which a blackout occurs is approximately 0.230 g/100mL

College students are one of the groups that are most prone for alcoholic blackouts, in part due to their binge drinking behavior.

Many persons with blackouts had to rely on others to provide details of what occurred during the blackout and often have a sense of dread or apprehension about what occurred.

Signs/Symptoms of Alcohol Blackout Compared to Severe Intoxication.

A recent literature review was conducted on alcohol induced blackout (Pressman and Caudill, 2013) that concluded that there is

"no objective or scientific method to verify the presence of an alcoholic blackout while it is occurring or to confirm its presence retrospectively. Even if such a method were available, valid and reliable, an alcoholic blackout would not negate mens rea as the experimental studies reviewed here report that only short-term memory is impaired and other cognitive functions- planning, attention, long-term memory required to form criminal intent- are not impaired."

The review also made a comparison of the signs and symptoms of alcoholic blackout compared with severe alcohol intoxication and is shown in the following table:

According to this review, alcoholic blackout patients did not typically appear to be fallen-down drunk and do not appear to be obviously impaired in coordination, balance, social interaction or speech.





References

Goodwin, D.W., "Alcohol Amnesia", Addiction, 90: 315-317, 1995

Goodwin, D.W., Crane, J.B., and Guze, S.B., "Alcoholic Blackouts: A Review and Clinical Study of 100 Alcoholics", American Journal of Psychiatry, 12*; 191-198, 1969

Pressman, MR., and Caudill, D.S., "Alcohol-Induced Blackout as a Criminal Defense or Mitigating Factor: An evidence-Based Review and Admissibility as Scientific Evidence.", Journal of Forensic Science, 58: 932-940, 2013









Wigmore on Alcohol

Read Wigmore on Alcohol: Courtroom Alcohol Toxicology for the Medicolegal Professional, Chapter 6.03 Blackouts and Memory, 268-274, Irwin Law (Publisher), 2011 available at www.wigmoreonalcohol.com





YouTube Video

Cannabis is another drug which also affects memory, see how at https://youtu.be/ZBLkW0lEvy8