Some systemic markers of inflammation in older adults with psychiatric disorders

Research has demonstrated that inflammation is a central part of several psychiatric disorders, of which depression in the most researched condition. Most studies have, however, been conducted on younger adults, and studies on elderly are scarce. This thesis explores the possible association between systemic markers of inflammation and characteristics of older psychiatric patients. In study I, we investigated possible correlations between the levels of 27 cytokines in plasma, and clinical and demographical variables, in diagnostically unselected in-patients that were 60 years and older (N = 98). We found no significant associations between cytokine levels and diagnoses, nor any other variables. However, we did find higher levels of 10 cytokines in the non-depressed patients, possibly as a result of the higher prevalence of cardiovascular disease and dementia. In study II, we explored whether changes in the level of 27 cytokines plasma during the treatment of diagnostically unselected psychiatric in-patients aged 60 years or more (N = 49) could be related to clinical and demographical variables, as well as self-reported clinical improvement. We found a positive correlation between clinical improvement and falling cytokine levels (p < 0.033), irrespective of psychiatric diagnoses or other variables. In study III, we investigated possible correlations between two levels of depression - moderate and moderate-severe depression - and CRP in serum, in younger (40 - 59 years) versus older adults (≥ 60 years) (N = 19,947). We found a multi-adjusted association between depression and elevated CRP in younger adults, but not in older adults. The studies of this thesis could not confirm an association between markers of systemic inflammation, and diagnoses and other characteristics of older adults with psychiatric disorders. In particular, this research could not, unlike most studies on younger adults, confirm a link between markers of systemic inflammation and depression in older adults