Drug-induced amnesia

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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, or certain medications for psychiatric disorders, such as benzodiazepines. [1] It is seen also with slow acting parenteral general anaesthetics.[ citation needed ]

Contents

Medical usage

Amnesia is desirable during surgery, so general anaesthesia procedures are designed to induce it for the duration of 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). [2] Amnestic drugs can be used to induce a coma for a child breathing using mechanical ventilation, or to help reduce intracranial pressure after head trauma. [3] [ failed verification ]

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. [1]

Holmes et al. (2010) [4] commented that the media misrepresented two recent studies as research on "erasing" traumatic memories, but showed the fear response associated with stressful memory 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. [5] 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 damped, 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.[ citation needed ] This has raised legal and ethical concerns should drugs be found to have altered the memory of traumatic events that occur in victims of crimes (e.g. murder attempt), and whether it is therapeutically desirable to do so. [4] [6]

Non-medical drug-induced amnesia

Amnesia can result from a side-effect of 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. [7]

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. [12] [13]

Related Research Articles

An anxiolytic is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxiety disorders and their related psychological and physical symptoms.

<span class="mw-page-title-main">Benzodiazepine</span> Class of depressant drugs

Benzodiazepines, colloquially called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, insomnia, and seizures. The first benzodiazepine, chlordiazepoxide (Librium), was discovered accidentally by Leo Sternbach in 1955 and was made available in 1960 by Hoffmann–La Roche, who soon followed with diazepam (Valium) in 1963. By 1977, benzodiazepines were the most prescribed medications globally; the introduction of selective serotonin reuptake inhibitors (SSRIs), among other factors, decreased rates of prescription, but they remain frequently used worldwide.

<span class="mw-page-title-main">Flunitrazepam</span> Benzodiazepine sedative

Flunitrazepam, also known as Rohypnol among other names, is a benzodiazepine used to treat severe insomnia and assist with anesthesia. As with other hypnotics, flunitrazepam has been advised to be prescribed only for short-term use or by those with chronic insomnia on an occasional basis.

<span class="mw-page-title-main">Psychopharmacology</span> Study of the effects of psychoactive drugs

Psychopharmacology is the scientific study of the effects drugs have on mood, sensation, thinking, behavior, judgment and evaluation, and memory. It is distinguished from neuropsychopharmacology, which emphasizes the correlation between drug-induced changes in the functioning of cells in the nervous system and changes in consciousness and behavior.

Post-traumatic stress disorder (PTSD) is a mental and behavioral disorder that develops from experiencing a traumatic event, such as sexual assault, warfare, traffic collisions, child abuse, domestic violence, or other threats on a person's life or well-being. Symptoms may include disturbing thoughts, feelings, or dreams related to the events, mental or physical distress to trauma-related cues, attempts to avoid trauma-related cues, alterations in the way a person thinks and feels, and an increase in the fight-or-flight response. These symptoms last for more than a month after the event. Young children are less likely to show distress, but instead may express their memories through play. A person with PTSD is at a higher risk of suicide and intentional self-harm.

<span class="mw-page-title-main">Propranolol</span> Beta blocker drug

Propranolol, sold under the brand name Inderal among others, is a medication of the beta blocker class. It is used to treat high blood pressure, a number of types of irregular heart rate, thyrotoxicosis, capillary hemangiomas, performance anxiety, and essential tremors, as well to prevent migraine headaches, and to prevent further heart problems in those with angina or previous heart attacks. It can be taken orally or by intravenous injection. The formulation that is taken orally comes in short-acting and long-acting versions. Propranolol appears in the blood after 30 minutes and has a maximum effect between 60 and 90 minutes when taken orally.

<span class="mw-page-title-main">Diazepam</span> Benzodiazepine sedative

Diazepam, first marketed as Valium, is a medicine of the benzodiazepine family that acts as an anxiolytic. It is commonly used to treat a range of conditions, including anxiety, seizures, alcohol withdrawal syndrome, muscle spasms, insomnia, and restless legs syndrome. It may also be used to cause memory loss during certain medical procedures. It can be taken orally, as a suppository inserted into the rectum, intramuscularly, intravenously or used as a nasal spray. When injected intravenously, effects begin in one to five minutes and last up to an hour. Orally, effects begin after 15 to 60 minutes.

<span class="mw-page-title-main">Sedative</span> Drug that reduces excitement without inducing sleep

A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but the majority of them affect the neurotransmitter gamma-aminobutyric acid (GABA). In spite of the fact that each sedative acts in its own way, most produce relaxing effects by increasing GABA activity.

<span class="mw-page-title-main">Depersonalization</span> Anomaly of self-awareness

Depersonalization is a dissociative phenomenon characterized by a subjective feeling of detachment from oneself, manifesting as a sense of disconnection from one's thoughts, emotions, sensations, or actions, and often accompanied by a feeling of observing oneself from an external perspective. Subjects perceive that the world has become vague, dreamlike, surreal, or strange, leading to a diminished sense of individuality or identity. Sufferers often feel as though they are observing the world from a distance, as if separated by a barrier "behind glass". They maintain insight into the subjective nature of their experience, recognizing that it pertains to their own perception rather than altering objective reality. This distinction between subjective experience and objective reality distinguishes depersonalization from delusions, where individuals firmly believe in false perceptions as genuine truths. Depersonalization is also distinct from derealization, which involves a sense of detachment from the external world rather than from oneself.

Encephalopathy means any disorder or disease of the brain, especially chronic degenerative conditions. In modern usage, encephalopathy does not refer to a single disease, but rather to a syndrome of overall brain dysfunction; this syndrome has many possible organic and inorganic causes.

Dissociation is a concept that has been developed over time and which concerns a wide array of experiences, ranging from a mild emotional detachment from the immediate surroundings, to a more severe disconnection from physical and emotional experiences. The major characteristic of all dissociative phenomena involves a detachment from reality, rather than a false perception of reality as in psychosis.

In neurology, anterograde amnesia is the inability to create new memories after an event that caused amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact. This is in contrast to retrograde amnesia, where memories created prior to the event are lost while new memories can still be created. Both can occur together in the same patient. To a large degree, anterograde amnesia remains a mysterious ailment because the precise mechanism of storing memories is not yet well understood, although it is known that the regions of the brain involved are certain sites in the temporal cortex, especially in the hippocampus and nearby subcortical regions.

A sympatholytic (sympathoplegic) drug is a medication that opposes the downstream effects of postganglionic nerve firing in effector organs innervated by the sympathetic nervous system (SNS). They are indicated for various functions; for example, they may be used as antihypertensives. They are also used to treat anxiety, such as generalized anxiety disorder, panic disorder and PTSD. In some cases, such as with guanfacine, they have also shown to be beneficial in the treatment of ADHD.

<span class="mw-page-title-main">Benzodiazepine dependence</span> Medical condition

Benzodiazepine dependence defines a situation in which one has developed one or more of either tolerance, withdrawal symptoms, drug seeking behaviors, such as continued use despite harmful effects, and maladaptive pattern of substance use, according to the DSM-IV. In the case of benzodiazepine dependence, the continued use seems to be typically associated with the avoidance of unpleasant withdrawal reaction rather than with the pleasurable effects of the drug. Benzodiazepine dependence develops with long-term use, even at low therapeutic doses, often without the described drug seeking behavior and tolerance.

Amnesia is a deficit in memory caused by brain damage or brain diseases, but it can also be temporarily caused by the use of various sedative and hypnotic drugs. The memory can be either wholly or partially lost due to the extent of damage that is caused.

The management of traumatic memories is important when treating mental health disorders such as post traumatic stress disorder. Traumatic memories can cause life problems even to individuals who do not meet the diagnostic criteria for a mental health disorder. They result from traumatic experiences, including natural disasters such as earthquakes and tsunamis; violent events such as kidnapping, terrorist attacks, war, domestic abuse and rape. Traumatic memories are naturally stressful in nature and emotionally overwhelm people's existing coping mechanisms.

PTSD or post-traumatic stress disorder, is a psychiatric disorder characterised by intrusive thoughts and memories, dreams or flashbacks of the event; avoidance of people, places and activities that remind the individual of the event; ongoing negative beliefs about oneself or the world, mood changes and persistent feelings of anger, guilt or fear; alterations in arousal such as increased irritability, angry outbursts, being hypervigilant, or having difficulty with concentration and sleep.

Memory erasure is the selective artificial removal of memories or associations from the mind.

Epigenetics of anxiety and stress–related disorders is the field studying the relationship between epigenetic modifications of genes and anxiety and stress-related disorders, including mental health disorders such as generalized anxiety disorder (GAD), post-traumatic stress disorder, obsessive-compulsive disorder (OCD), and more. These changes can lead to transgenerational stress inheritance.

<span class="mw-page-title-main">Post-traumatic stress disorder and substance use disorders</span> Association of PTSD and substance dependencies

Post-traumatic stress disorder (PTSD) can affect about 3.6% of the U.S. population each year, and 6.8% of the U.S. population over a lifetime. 8.4% of people in the U.S. are diagnosed with substance use disorders (SUD). Of those with a diagnosis of PTSD, a co-occurring, or comorbid diagnosis of a SUD is present in 20–35% of that clinical population.

References

  1. 1 2 Curran, H. Valerie. "Psychopharmalogical Perspectives on Memory." Oxford Handbook of Memory. Oxford: Oxford University Press, 2000.
  2. ↑ Baddeley, Alan (2002). The handbook of memory disorders. New York: J. Wiley. pp. 127–8. ISBN   0470856300.
  3. ↑ Bernstein, Daniel (2003). Pediatrics for Medical Students . Philadelphia: Lippincott Williams & Wilkins. ISBN   0781729416.
  4. 1 2 Holmes, E. A., Sandberg, A., & Iyadurai, L. (2010). Erasing trauma memories. The British Journal of Psychiatry, 197(5), 414-415.
  5. ↑ Brunet, A1, Orr, SP, Tremblay, J., Robertson, K., Nader, K., Pitman, RK (May 2008). "Effect of post-retrieval propranolol on psychophysiologic responding during subsequent script-driven traumatic imagery in post-traumatic stress disorder". J Psychiatr Res. 42 (6): 503–6. doi:10.1016/j.jpsychires.2007.05.006. PMID   17588604.{{cite journal}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
  6. ↑ Steckler, T. and Risbrough, V. "Pharmacological treatment of PTSD–established and new approaches." Neuropharmacology 62.2 (2012): 617-627. PMC   3204327 doi : 10.1016/j.neuropharm.2011.06.012
  7. ↑ Sadock, Benjamin (2008). Kaplan & Sadock's concise textbook of clinical psychiatry. Philadelphia: Wolters Kluwer/Lippincott Williams & Wilkins. ISBN   978-0781787468.
  8. ↑ Gray, Richard. "Scientists find drug to banish bad memories." The Telegraph, 2007 Jul 1.
  9. ↑ Aelanna. "Dr. Mackenzie's Glossary of Terms". SCP Foundation. Retrieved 2 August 2015.
  10. ↑ "NIMH » Memory-sustaining Enzyme May Help Treat PTSD, Cognitive Decline". www.nimh.nih.gov. Archived from the original on 2018-04-23. Retrieved 2016-12-28.
  11. ↑ "Scientists raise new questions on molecular key to memory". Ars Technica. Retrieved 2016-12-28.
  12. ↑ πένθος . Liddell, Henry George ; Scott, Robert ; A Greek–English Lexicon at the Perseus Project.
  13. ↑ Homer; Murray, A.T. (translator) (1919). "4.219-221". Odyssey.{{cite book}}: |first2= has generic name (help) "4.219-221". Odyssey (in Greek). At the Perseus Project.
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