Prevalence and clinical correlates of cognitive symptoms in depression: A naturalistic study

MANCHIA M.

Writing – Original Draft Preparation

;ORRU M. G.;PERRA V.

Data Curation

;PINNA F.

Writing – Review & Editing

;CARPINIELLO B.

Writing – Review & Editing

2020-01-01

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Abstract

Background. Treated mood disorder (MD) patients suffer from residual cognitive symptoms, even when treatment response is considered adequate. Here we estimated the prevalence of cognitive impairment and tested whether the severity of self-rated and clinicianrated cognitive symptoms differed between remitted and unremitted MD patients. Methods. Forty-three consecutive MD patients were recruited at an academic community mental-health centre at the University of Cagliari, Cagliari, Italy. Patients had to have a diagnosis of major depressive disorder (MDD), bipolar disorder (BD) type 1 or type 2, or unspecified depressive disorder according to the Diagnostic Statistical Manual (DSM)-5 criteria. Cognitive function was assessed using self-rated [Perceived Deficits Questionnaire - Depression, 5-item (PDQ-D-5)] and clinician-rated [Digit Symbol Substitution Test (DSST) measures and the short version of the Mini Mental State Examination (sMMSE)] tools. Standard statistical tests were applied. Results. The prevalence of cognitive symptoms ranged from 20.9% to 44.2%, depending on the assessment tool used. There were no statistically significant differences in self-rated and clinician-rated measures of cognitive function between remitted and unremitted patients as well as no statistically significant correlation between self-rated and clinician-rated measures of cognitive function. Patients with better education had higher mean scores at the sMMSE and the DSST. Discussion and conclusions. We confirmed that cognitive symptoms are highly prevalent in MD patients, irrespective of the mood state. This suggests that cognitive impairment in MD is a trait, rather than a state marker. The absence of a correlation between self-rated and clinician-rated (objective) measures of cognitive impairment suggests that each assessment tool captures a specific facet of cognitive function.