Drug-induced amnesia

Drug-induced amnesia is amnesia caused by drugs. Amnesia may be therapeutic for medical treatment or for medical procedures, or it may be a side-effect of a drug, such as alcohol, rohypnol or certain medications for psychiatric disorders, such as benzodiazepines.

Medical usage

Amnesia is desirable during surgery, since a general anasthetic should also give the person amnesia for the operation. Sedatives such as benzodiazepines which are commonly used for anxiety disorders, can reduce the encoding of new memories, particularly in high doses (for example, prior to surgery in order for a person not to recall the surgery). Amnesiac drugs can be used to induce a coma for a child breathing using mechanical ventilation, or to help reduce intracranial pressure after head trauma.

Amnesia can be caused by sedated due to intramuscular injections during a psychiatric emergency, for example violent patients or those with psychomotor disturbance after a seizure may need sedation. Typically patients have complete amnesia for the episode.

Researchers are currently experimenting with drugs which induce amnesia in order to improve understanding of human memory, and develop better drugs to treat psychiatric disorders and memory related disorders. People with Alzheimer's Disease and other forms of dementia are likely to benefit. By understanding the ways in which amnesia-inducing drugs interact with the brain, researchers hope to better understand the ways in which neurotransmitters aid in the formation of memory. By stimulating rather than depressing these neurotransmitters, memory may improve.

The use of a drug to erase traumatic or unwanted memories used to be referred to as "science fiction." Holmes et al. (2010) commented that the media misrepresented two recent studies as research on "erasing" traumatic memories, but they actually fact showed the fear response could be greatly reduced whilst the factual memory of the trauma remained intact. Similarly, Brunet et al. (2008) found that the people with chronic Posttraumatic Stress Disorder who were treated with propranolol for a single day had a reduced response to existing trauma while retaining memory of the trauma. In the process of remembering, the memory needs to be restored in the brain. By introducing an amnesia-inducing drug during this process, the memory can be disrupted. While the memory remains intact, the emotional reaction is dampened, making the memory less overwhelming. Researchers believe this drug will help patients with post-traumatic stress disorder be able to better process the trauma without reliving the trauma emotionally. This has raised legal/ethical concerns should drugs be found to have altered the memory of traumatic events that occur in victims of crimes (e.g. rape), and whether it is therapeutically desirable to do so.

Non-medical drug-induced amnesia

Amnesia can result from a side-effect or prescription or non-prescription drugs. Both substance use and alcohol can cause both long-term and short-term memory loss, resulting in blackouts.

The most commonly used group of prescription drugs which can produce amnesia are benzodiazepines, especially if combined with alcohol, however, in limited quantities, triazolam (Halcion) is not associated with amnesia or memory impairment.

In popular culture

In the 1970 science fiction TV series UFO, amnesia drugs were given to anyone who had contact with SHADO operatives, or witnessed their covert activities.

Eternal Sunshine of the Spotless Mind (2004) stars Jim Carrey and Kate Winslet. Both characters attempt to erase each other from their memories, due to a failed relationship. As the memory erasure begins, they attempt to hold on to the memories.

In an episode of the TV series Private Practice, a patient requests propranolol in order to forget a sexual assault. The drug is never used because of possible side effects and its experimental status.

The characters in The Hangover (2009) deal with the aftermath of amnesia after taking roofies.

An episode of Arrested Development called Forget-Me-Now discusses the use of drug-induced amnesia for those who have figured out the magician's tricks (or illusions).

In the PC Game Amnesia: The Dark Descent (2010) a character by the name of Daniel wakes up with self-induced amnesia in the terrifying Castle of Brennenburg to discover the truth about his memories.

In the book Allegiant (novel) (2013) a "memory serum" is used to wipe the memories of people

In Mythology

Nepenthe; literally named anti-sorrow, is a substance mentioned in the Odyssey given to Helen of Troy; said to originate from Egypt. Consumption causes sorrowful memories to be forgotten.