Can Depression Cause Cognitive Impairment (Thinking Problems)?
Most people think of depression as causing emotional changes, but can depression cause cognitive impairment too? Studies show that not only does depression cause emotional and physical symptoms, but it also causes cognitive dysfunction (problems with thinking). Cognitive dysfunction is also seen in bipolar disorder and quite markedly in schizophrenia. If you're wondering, "Do I have cognitive dysfuction because of depression?", take our Cognitive Symptoms (Deficits) of Depression Test. It's free and instantly scored.
What is Cognitive Dysfunction?
Cognitive function refers to thinking and intellectual skills that allow you to perceive, acquire, understand and respond to information. These skills include things like memory, the ability to pay attention and solve problems and communication as well as the ability to organize, recognize and act on information. When the terms "cognitive dysfunction" or "cognitive impairment" are used, they indicate that there are problems in one or more of these areas. Everyone is born being better or worse at certain cognitive skills but whether affected by depression or not, these cognitive skills can be strengthened and improved over time.
Depression and Cognitive Deficits
Cognitive deficits refer to the specific areas in which cognitive dysfunction is seen and depression is associated with five areas of cognitive deficits:
- Attention, Concentration
- Psychomotor skills (relating to muscular activity associated with thought)
- Brain processing speed (slow thinking)
- Decision making
Not all studies show the same cognitive impairment levels or areas, but what does seem consistent throughout research studies is that:
- Not all people suffer from cognitive dysfunction in depression (but the vast majority do)
- Not all people with depression experience cognitive dysfunction in the same ways
- More severe depressions produce greater cognitive dysfunction
- More incidences of depression cause greater cognitive dysfunction
- Older individuals with depression suffer from greater cognitive dysfunction
- Psychotic depression produces greater levels of cognitive dysfunction
Video courtesy of Global Medical Education
Does Depression Cause Cognitive Dysfunction?
Issues with depression and cognitive dysfunction have been acknowledged for a long time but previously, it was often thought to be secondary to the other symptoms of depression. For example, due to lack of motivation (common in depression), it was thought that people with depression simply weren't motivated to accomplish the cognitive tasks asked of them. (Do you have cognitive dysfunction? Take our cognitive symptoms of depression test.)
Now, however, researchers believe this not to be true. Not only do we know of the cognitive deficits present during acute depression episodes but we also know that some cognitive deficits do not completely go away even when depression is in remission. Impairments in memory is one such deficit that has been shown to be present even when the person is in recovery, independent of medication status.
Additionally, through brain scans, it is now known that depression negatively affects brain volume in some areas and that may be one reason people experience impaired functioning in cognitive areas.
Other Causes of Cognitive Dysfunction in Depression
Of course, it's also important to remember that improper dosing of depression medication can also cause cognitive impairment in depression. If someone is taking too high a dose of an antidepressant or antipsychotic, for example, they may exhibit similar, or worsening, symptoms of cognitive deficits. Careful work with a doctor can prevent this from occurring.
Drug and alcohol abuse can also cause, or worsen, cognitive deficits and this, unfortunately, is all too common in people with major depressive disorder.
Finally, cognitive deficits also appear to be more pronounced the more an individual with depression focuses on their depression (ruminates). This is often seen when people are under greater than usual amounts of stress.