Amnesia simply means loss of memory; it is when a person cannot recall information stored in their memory. Every person has the ability to recall events and experiences from the information they have stored in their brain. However, people with amnesia often lose the memory of important events, milestones, people in their lives, and the things they have learnt.  

Most people with amnesia may recall full memories up to a certain point in their lives but have difficulty remembering things afterwards. In other cases, they may lose memories from before a certain point. 

These people also find it hard to think of the future because the human brain can only create future scenarios from its collections of past experiences. 

Types of Amnesia

Amnesia can be of different types and symptoms; a person can have multiple types, so the symptoms will also overlap.

Infantile Amnesia

This type of amnesia is normal; it is the loss of memory from when you were a baby; everyone experiences it.

Post-traumatic Amnesia

This is memory loss after an injury; it can be from a hard blow to the head or an accident. It is usually temporary, depending on the severity of the injury. 

Dissociative Amnesia

This is a type of amnesia that occurs due to a mental health disorder; it can stem from abuse, traumatic events and other sources of psychological distress. This amnesia is like the brain’s defence mechanism to protect people from what they have experienced.  

Transient Global Amnesia

This is a temporary memory loss which can get worse and make it difficult for a person to form new memories. It usually doesn’t last more than 24 hours and is more common in older adults with vascular disease. 

Causes

Amnesia can be caused by many reasons, which fall under two categories: 

Neurological Causes of Amnesia

These are conditions that cause damage to the brain or disruptions in brain activities and then lead to amnesia. They include:

• Alzheimer’s disease.
• Alcohol intoxication.
• Brain tumours.
• Brain aneurysms.
• Epilepsy and seizures.
• Drugs and medications, especially anaesthesia or sedatives.
• Cerebral hypoxia.
• Toxins and poisons like heavy metal poisoning or carbon monoxide poisoning.
• Frontotemporal dementia.
• Infections like encephalitis.
• Head injuries like traumatic brain injuries (TBIs) or concussions. 
• Stroke.
• Wernicke-Korsakoff syndrome.
• Other degenerative brain diseases like multiple sclerosis or Parkinson’s disease.

Psychological Causes of Amnesia

Amnesia can also be caused by mental health issues such as PTSD, any case that involves a traumatic event or severe emotional and mental stress. In such situations, the brain loses memories to protect people from their experiences. 

Symptoms 

The symptoms of amnesia include:

• Impaired ability to remember past events and previously familiar information.
• Impaired ability to learn new information.
• Experiencing false memories.
• Impaired short-term memory.
• Confusion.
• Partial or total loss of all memory.
• Not remembering locations.
• Difficulties recognising faces and remembering names. 

Treatment

There is no specific way to treat amnesia; if it is caused by an underlying condition, it will be treated first because many conditions can cause amnesia. Some people may also recover their memories with time.

A doctor may recommend cognitive rehabilitation and occupational therapy to help teach you skills and techniques that can compensate for your memory loss.