Association of cognitive symptoms with perceived stress among a cohort of systemic lupus erythematosus patients, August 2011–July 2012. Triangles, forgetfulness (severe/moderate vs. mild/none); squares, difficulty concentrating (all/most vs. some/little/none of the time). MID, minimal important difference (=4.03 points); PSS, perceived stress score. Sociodemographics include age group, sex, race, and education; disease activity includes the Systemic Lupus Activity Questionnaire score (excluding the forgetfulness item).