Frank P, Jokela M, Batty GD, et al. - In this random-effects pooled analysis of 15 population-based cohorts and 56,351 individuals aged 18 years and older, the associations between systemic inflammation and an array of individual symptoms of depression were examined.

• Depressive symptoms were prevalent ranging from 1.1% (suicidal ideation) to 21.5% (sleep problems).

• In cross-sectional analyses, risk of experiencing four physical symptoms (changes in appetite, felt everything was an effort, loss of energy, sleep problems) and one cognitive symptom (little interest in doing things) appeared higher in robust correlation with the presence of higher concentrations of CRP.

• The overall evidence was strongly against an association with inflammation for four exclusively emotional symptoms (bothered by things, hopelessness about the future, felt fearful, life had been a failure).

• Systemic inflammation has symptom-specific rather than generalized effects on depression.