Study Shows Association Between Pain and Depression in Dementia

Abstract

Pain and depression are strongly related in dementia regardless of analgesic or antidepressant use, a large, prospective Norwegian study has shown. This study (J Affect Dis 2017;218:8–14) combined prospective data on 931 patients, two-thirds of whom were women, all with mild cognitive impairment and an average age of 85.4 years. The data were taken from two independent studies of multiple nursing homes in Norway. In the first study, 684 individuals with dementia who lived in one of 47 centers were evaluated at baseline and at 6 months between January 2012 and June 2014. In the second study 247 individuals with dementia living in one of 26 centers were analyzed for pain and depression at baseline and at 4 months between April 2014 and June 2015. In both studies, cognitive function was assessed using the Mini-Mental State Examination (MMSE). Pain was assessed using the Mobilization-Observation-Behavior-Intensity-Dementia-2 (MOBID-2) pain scale. Depression was measured using the Cornell Scale for Depression in Dementia (CSDD). The Neuropsychiatric Inventory–Nursing Home version (NPI-NH) assessed neuropsychiatric symptoms; the NPI depression subscale scores were used as secondary outcome measures. Pain at baseline was statistically significantly associated with depression at the follow-up points in both studies; however, after adjusting for covariates, only the second study retained the statistically significant association. Meanwhile, unadjusted rates of depression at baseline were statistically significantly associated with pain at follow-up evaluation in both studies, but only the first study retained its statistically significant association after adjusting for covariates. In their mixed model analyses, Ane Erdal, a PhD candidate in the global public health and primary care department and Centre for Elderly and Nursing Home Medicine at the University of Bergen in Norway, and her colleagues found that the patients with more pain were statistically significantly more depressed than those with less pain, and that the reverse was also true. An increase of 1 point on the MOBID-2 scale was associated with an increase of 0.48 on the CSDD scale and also with an increase of 0.11 on the NPI depression subscale. An increase of 1 point on the CSDD scale was associated with an increase of 0.10 on the MOBID-2 scale. The use of analgesics was shown to be statistically significantly associated with both pain and depression. Residents who received an increased number of analgesics from baseline to follow-up had statistically significantly increased pain and increased depression during the same period. The number of antidepressants prescribed to a resident was statistically significantly associated with their depressive symptoms, but this was not true for pain. When pain and depression were assessed according to levels of cognitive function, pain was statistically significantly associated with increased depression in people with mild and moderate cognitive impairment. It was nearly statistically significant in residents with severe cognitive impairment, but was not statistically significantly associated in those with no impairment or whose impairment was questionable. Depression was similarly associated with pain in mild, moderate, and severe cognitive impairment, but not in those with either no impairment or questionable impairment. The authors concluded that over time, reduced pain intensity is associated with future reductions in depressive symptoms across all levels of cognitive impairment, and that consideration of the equipoise of analgesic and antidepressant prescribing in this population is particularly important. Helen Jones is a NJ-based freelance writer.