Differential reports of pain and depression differentiate mild cognitive impairment from cognitively intact elderly participants

Background: Positive associations between pain and depression in the general population have been well characterized; however, the interplay between pain, depression, and early cognitive decline, characterized as mild cognitive impairment (MCI), is poorly understood. Methods: The current study examined the association of self-reported pain complaints (measured by the 36-item Short Form Health Survey) and self-reported depressive symptoms (measured by the 30-item Geriatric Depression Scale) in cognitively intact participants (n = 492) and participants with a clinical diagnosis of MCI (n = 83). Results: Depressive symptoms and subjective reports of pain were significantly associated in the entire sample (r =.29; P <.0001). Multiple logistic regression modeling (adjusted for age, education, and APOE4 status as covariates) demonstrated that while depressive symptoms were positively associated with the diagnosis of MCI (P <.001), subjective pain reports were negatively associated with MCI (P <.002). Conclusion: While the negative association of subjective pain complaints with MCI might arguably be explained by the development of anosognosia, self-reports of depressive symptoms were actually increased in these participants, suggesting preserved insight into cognitive decline-associated symptoms. It is possible that preferential involvement of limbic circuitry in MCI could explain these findings. Future studies are needed to elucidate the reasons for the dissociation of pain and depressive symptoms in MCI described in the present article.