The truth is this: we’ve all forgotten something once or twice.

We’ve all had that experience of “Where did I put my keys?” or “What was I just saying?”, or even “Where did I park my car?”

Annoying as these things might be, they are common, normal, and healthy.

Until they’re not.

When these situations become more frequent, that’s when they can become problematic.

Once your memory loss starts to affect your activities of daily life, that’s when it’s time to seek treatment.

Common signs of memory loss

We have short-term memory loss and long-term memory loss.

We have separate, distinct neurobiological stores of each of these types of memory.

Short-term memory is for previously unencountered information (1).

Long-term memory is divided into two different types: procedural and declarative.

Procedural memory involves activities that we learn by practicing and through repeated exposure.

Examples of procedural memory include riding a bike or driving a car.

Declarative memories are then broken down into two different types: semantic and episodic.

Semantic memories are discrete facts. Examples of semantic memories include dates, word definitions, and learned concepts.

Episodic memories are explicit experiences that a person has lived through. Examples of episodic memories include a special birthday or your wedding day.

Long-term memory is consolidated from short-term memory in the hippocampus. These memories are then stored throughout the cortex of the brain (2).

Is memory loss only related to aging?

Loss of memory and aging are certainly linked.

As we age, neural stem cells have reduced proliferation and neuron production.

This is what’s thought to contribute to age-related memory loss and reduced plasticity of the brain, which is necessary for certain parts of the brain to repair (3).

However, aging is not the only way that we experience cognitive decline and memory loss.

Main causes of memory loss

Sleep deprivation

More than a century’s worth of research has solidified the fact that sleep benefits memory retention.

Current scientific theories say that memories undergo a process of system consolidation while we sleep.

Slow-wave sleep is most important for memory consolidation.

Essentially, sleep is a brain state that optimizes memory consolidation.

Slow-wave sleep in particular helps to transform memories into long-term memories.

REM sleep, which comes after slow-wave sleep, then stabilizes these transformed memories (4).

Depression and stress

Research has demonstrated that prospective memory can be impaired in patients with psychiatric disorders, including depression.

One study, in particular, found that when compared with healthy controls, patients with depression had significant impairment in event-based prospective memory.

They also found that time-based prospective memory was significantly impaired in those with depression (5).

Stress and memory loss are also certainly linked.

Studies have shown that when stress occurs just prior to or during memory retrieval, memory is impaired.

Stress consistently increases cortisol levels, and can disrupt certain episodic memory processes (6).

Drug use

A study compared healthy controls to heavy drinkers and regular users of drugs (this included recreational drugs, alcohol, and tobacco).

The research showed that the drug-using group tended to perform worse than the control group on both event and time-based progressive memory tasks.

These impairments were moderate to severe in nature. This was likely due to brain cell damage in the drug and alcohol group of patients.

It’s also worth noting that the subjects were not under the influence of drugs or alcohol during the actual time of the study, they were simply affected by their regular use of drugs and alcohol (7).

B12 deficiency

B12 deficiency can lead to symptoms that are neurologic, cognitive, psychiatric, and mood-related in nature.

One study looked at 259 patients with vitamin B12 deficiency.

Out of these 259 patients, 41 of them had some form of dementia.

The first symptom that 33.9% of these patients presented with was memory loss.

Of those with severe B12 deficiency, 84.2% of them had memory loss.

Vitamin B12 increases the load of cognitive decline.

It accentuates vascular risk factors in neuropsychiatric illnesses.

It does this by increasing homocysteine levels, which have been linked to dementia and Alzheimer’s disease (8).

So, who can suffer from memory loss?

Seniors may exhibit more symptoms of memory loss, due to brain health degeneration that occurs naturally with aging.

However, we are all exposed to memory loss due to lifestyle conditions such as sleep deprivation, stress, depression, vitamin B12 deficiency, and the use of alcohol, drugs, and tobacco.