Chronic pain linked to memory decline and dementia in new study

Written by Francesca Lake

New research from a team at the University of California San Francisco (UCSF; CA, USA) has demonstrated that chronic pain is linked to memory decline and dementia in older adults. The study provides the first suggestion that chronic pain is related to brain changes that contribute to dementia.
The research analyzed data from the American Health and Retirement Study. Their study comprised analysis of biennial interviews of 10,065 community-dwelling adults aged over 62 years in 2000. The participants who indicated they were persistently troubled by moderate or severe pain in both 1998 and 2000 demonstrated a 9.2% faster decline in memory function tests over the next 10 years compared with those not troubled by pain. The moderate or severe pain group also demonstrated an increased likelihood of developing dementia.

“Elderly people need to maintain their cognition to stay independent,” commented Elizabeth Whitlock (UCSF), first author of the study. “Up to one in three older people suffer from chronic pain, so understanding the relationship between pain and cognitive decline is an important first step toward finding ways to help this population.”

The team suggested use of painkillers or the impact of pain experience on the brain’s cognitive functions could be responsible for the association. Some possibilities include the distraction of pain resulting in lack of memory consolidation, or pain resulting in the activation of stress-hormone pathways that have been implicated in cognitive decline. However, the study did not include data on sufficient factors to determine the reason behind relationship.

Although the reason for the association is unclear, the team expects their findings will have clinical utility, with pain used as a marker for risk of cognitive decline. Furthermore, further investigation of the causes of the relationship could result in treatment of pain being used to protect cognition.

Sources: Whitlock EL, Diaz-Ramirez LG, Glymour MM et al. Association between persistent pain and memory decline and dementia in a longitudinal cohort of elders. JAMA Intern. Med. doi:10.1001/jamainternmed.2017.1622 (2017) (Epub ahead of print);