Depression and Memory

According to the National Institute of Mental Health, depressive illnesses affect more than 20 million Americans each year. People who suffer from depression can be overwhelmed by an unbearable sadness and a sense of hopelessness that makes it difficult to carry on or plan ahead. The disorder can affect their ability to work and damage important relationships. It can lead to cardiac problems and osteoporosis, and complicate the treatment of other medical conditions.

Depressive illnesses can also damage brain structures like the hippocampus, reduce brain cell activity in the prefrontal cortex, and potentially lead to cognitive declines and memory complaints. Studies show that episodic, conscious memory for facts appears to be particularly vulnerable.

The kinds of memories people recall when they are depressed are often negatively skewed. People tend to retrieve memories that correspond to their mood -- when we are happy we reflect on positive experiences, but when we are sad we often remember less pleasant events. Depressed people tend to recall unhappy experiences most of the time.

Studies have shown that depressed participants have a comparatively harder time trying to recall memories from earlier periods of life. Intrusive, unwanted thoughts about their worries often get in the way. When they are able to consciously retrieve memories, relatively recent events and experiences, many of them negative, tend to quickly come to mind.

Depressed people also appear to have a harder time remembering richly-detailed autobiographical memories. Even when they are asked for specific memories about past events, depressed study participants often retrieve only the gist or essence of the recollection. Why do they report these overgeneral memories? It may be that they didn't encode enough information at the time the event happened. Another explanation is that the memories sought are blocked out selectively because they are distressing.

Psychologists at the University of London found that depressed study participants who had intrusive memories and tried to avoid them also tended to produce overgeneral memories. Whereas distressing, intrusive memories predicted prolonged episodes of depression, overgeneral memories did not.

Symptoms of depression in the elderly are sometimes overlooked, either because the illness can present differently at later ages, or because health care professionals and older adults themselves consider it a normal part of aging.

One atypical form of depression sometimes seen in older adults is called pseudodementia. Elders who have this condition may go to see their doctors complaining that their memory is failing, not mentioning the emotional disturbances or physical ailments that are also often associated with depression. As a result, physicians may mistakenly conclude their patients are suffering from a dementing illness like Alzheimer's Disease.

There are some key differences that distinguish the memory complaints reported by elders suffering from pseudodementia and dementia. First, the onset of cognitive impairment is often rapid for those with depression. Second, elders with depression are more aware of how their memory has changed. Finally, whereas memory problems lift when depression is treated, elders with dementia will develop progressively worse deficits.

Seek out the help of a physician or qualified mental health professional if you think you may be depressed. The National Institute of Mental Health offers the following suggestions as you begin treatment:

Set realistic goals in light of the depression and assume a reasonable amount of responsibility.

 

Break large tasks into small ones, set some priorities and do what you can as you can.

 

Try to be with other people and confide in someone; it is usually better than being alone and secretive.

 

Participate in activities that may make you feel better.

 

Mild exercise -- going to a movie, a ballgame or participating in religious, social or other activities -- may help.

 

Expect your mood to improve gradually, not immediately. Feeling better takes time.

 

It is advisable to postpone important decisions until the depression has lifted. Before deciding to make a significant transition, discuss it with others who know you well and have a more objective view of your situation.

 

Remember, positive thinking will replace the negative thinking that is part of depression and will disappear as your depression responds to treatment.

 

Let your family and friends help you.

Posit Science works with more than 50 brain scientists at leading universities to develop programs that enhance cognitive abilities. The organization offers relevant information about brain science, tips for keeping your brain sharp, assessments for checking your brain fitness, and much more.

Get tips to help retain your memory, avoid cognitive decline and keep your brain as sharp as possible with the Brain Fitness Insider.

Think you might be depressed? Visit our depression guide.

How good is your memory? Find out.