Cognitive Biases and Insomnia Symptoms in People With and Without Chronic Pain

Chronic pain and insomnia symptoms are highly comorbid; however, the psychological mechanisms driving this comorbidity are not well understood. The aim of the present study was to assess whether 2 cognitive biases that occur separately in chronic pain and insomnia, that is, interpretation bias and attentional bias, are heightened in people with comorbid chronic pain and elevated insomnia symptoms. A final sample of N = 109 people with chronic pain and N = 79 people without pain who varied in insomnia symptoms were recruited through Prolific Academic to complete this cross-sectional study. Participants completed measures of sleep and pain-related interpretation bias (ambiguous sentences task) and attentional bias (dot-probe task), as well as questionnaires assessing insomnia symptoms, pain symptoms, and general psychological symptoms. We found an interaction between pain status and insomnia symptoms for sleep-related interpretation bias. That is, people with chronic pain showed greater sleep-related interpretation bias than those without pain, but only when insomnia symptoms were also elevated. This interaction did not extend to pain interpretation bias or attentional bias, although we did find an elevated pain interpretation bias in people with chronic pain compared to pain-free individuals. We also found that both pain and sleep-related interpretation bias were associated with depression symptoms, suggesting that interpretation bias could potentially drive a trimorbidity of chronic pain, insomnia, and depression. Taken together, these findings suggest promise for the role of interpretation bias in the mutual maintenance of chronic pain and insomnia symptoms and the importance of also considering depression.