“Treating these chronic conditions together may minimize the stigma of depression treatment and improve treatment acceptability,” Dr. Karp said.
Cognitive impairment is common in late-life depression, affecting executive functioning, attention, and memory; it is associated with long-term risk for dementia. “Cognitive deficits may thus be signs of accelerated brain aging that confers a predisposition to and perpetuates depression,” Dr. Karp said.
How pain contributes to treatment response variability
A 2002 study by Brown et al that involved 121 community-dwelling rheumatoid arthritis patients aged 34 to 84 years sought to examine the effects of pain and depression on cognitive function.5 Participants completed a battery of cognitive tasks, and pain and depression were assessed using multiple measures. The researchers then used structural equation modeling to assess how pain, depression, and age contributed to cognitive performance.
Higher levels of pain and depression and older age were associated with poor performance on cognitive tasks, the researchers found. Similarly, higher levels of pain were associated with depression, and analyses revealed that depression mediated the relationship between pain and cognition.
“When depression was entered into the analyses, the previously significant effects of pain on cognition were no longer found,” Dr. Karp reported. “Interestingly, depression still mediated the pain-cognition relationship even after controlling for age.”
Because the effects of pain and depression—cognitive impairment, disability, insomnia, physical deconditioning, polypharmacy, high costs, and worsening caregiver burden—are interrelated, Dr. Karp advises the use of a unified approach.