In an elderly patient, the symptoms of severe depression can look like a dementia. This is sometimes referred to as Depressive pseudodementia or just pseudo-dementia. In fact, it may represent one of the most common causes of reversible cognitive impairment (ie loss of memory or other thinking abilities which are not permanent, but can be reversed with treatment). Patients with pseudodementia may have impaired memory, learning, and cognitive function, just like those with dementia, in addition to the symptoms of depression. Symptoms of depression may include sad mood or irritability, difficulty concentrating, reduced interests, motivation and activity, or changes in normal sleep and appetite. People with pseudodementia may be more aware of their memory problems than people with a true dementia. They may also do better on certain tests of memory and thinking – for example if given a hint they may remember things well.
Furthermore, people with pseudodementia may have a history of depression or a recent significant upsetting life event. Therefore, the onset of pseudodementia may be more abrupt than, for example, Alzheimer’s disease. The diagnosis is usually made either by an internist or geriatrician who is attuned to depression or by a psychiatrist. Treatment with antidepressant medication or psychotherapy leads to an improvement in memory and thinking. It is important to realize that some patients with depressive pseudodementia will eventually progress to irreversible dementia, and so individuals with pseudodemtntia should continue to have their memory and thinking evaluated. It’s also important to remember that as many as 20-40% of people with dementia may also suffer from depression.