Those afflicted with anxiety may be even more anxious to learn of a new study that finds people who experienced high anxiety any time in their lives had a 48% higher risk of developing dementia compared to those who had not.
The USC study was based on findings from the Swedish Adoption Twin Study of Aging, which traced 28 years of data involving 1,082 participants -- twins, fraternal and identical. The study subjects completed in-person tests every three years, answered several questionnaires, and were screened for dementia throughout the study.
Many other studies have explored the link between dementia and psychological variables such as depression and neuroticism. However, this study established that the anxiety-dementia link was independent of the role of depression as a risk factor.
"Anxiety, especially in older adults, has been relatively understudied compared to depression," said Andrew Petkus, the study's lead author and postdoctoral research associate of psychology in the USC Dornsife College of Letters, Arts and Sciences. "Depression seems more evident in adulthood, but it's usually episodic. Anxiety, though, tends to be a chronic lifelong problem, and that's why people tend to write off anxiety as part of someone's personality."
A final draft of the study was made available online last week in Alzheimer's & Dementia: The Journal of the Alzheimer's Association.
"Frantic, frazzled people"
The researchers noted that the subjects had self-reported various levels of anxiety, which may or may not meet the clinical diagnostic threshold of a psychiatric anxiety disorder. Even so, the twin who developed dementia had a history of higher levels of anxiety compared to the twin who did not develop dementia.
The subjects with anxiety who later developed dementia "are people that experience more than usual symptoms of anxiety," said study co-author Margaret Gatz.
"They are people who you would say operate at a 'high level of anxiety,'" said Gatz. "They are frantic, frazzled people."