It's well known that people with dementia often suffer from anxiety and depression, but now researchers are realizing that symptoms of depression and anxiety actually wax and wane as cognitive dysfunction increases.
The cognitive changes of dementia -- impairment of memory, learning, attention, and concentration -- can also occur in people who are depressed, making the diagnosis of dementia more difficult. In fact, depression and cognitive decline often occur together.
Now a study in the journal Dementia and Geriatric Cognitive Disorders (Volume 24, page 213) shows that symptoms of depression and anxiety actually wax and wane as cognitive dysfunction increases.
The researchers compared four groups in various stages of cognitive decline from a community-based sample and a clinical sample of older people diagnosed with Alzheimer's. The prevalence of anxiety and depression symptoms among people in various stages of cognitive decline was established, then analyses were conducted to determine differences between the levels of cognitive functioning.
Anxiety symptoms were noted in 8.6% of people with good cognitive functioning, rising to 11.8% in those with moderate functioning and dropping to 10.7% in those with poor functioning. Similarly, depressive symptoms were found in 8.9% of those with good functioning, 22.1% of those with moderate functioning, and 21.1% of those with poor functioning. Of those diagnosed with Alzheimer's disease, only 6% had anxiety and 16.7% suffered from depression.
The increase in depression and anxiety symptoms earlier in the course of cognitive decline may be attributed to individuals noticing the decrease in functioning, while in later cognitive decline (and Alzheimer's) anxiety and depression may appear to decrease due to lack of awareness.
