TABLE 1A.

Main characteristics of systematic reviews dealing with the association between periodontitis and depression: material and methods.

Materials and methods
References	Inclusion criteria	Exclusion criteria
Araújo et al. (48)	(P) Patients: adult humans (E) Exposition: presence of depressive disorders (C) Comparison: control patients without depression (O) Outcomes: clinical periodontal parameters (PD, CAL, BOP) (S) Studies: cross-sectional, case-control, cohort studies; clinical trials	Case reports or reviews Other mental or systemic diseases Absence of healthy control patients Outcomes other than periodontitis
Liu et al. (49)	(P) Patients: adult humans (E) Exposition: chronic periodontitis (C) Comparison: periodontally healthy individuals (O) Outcomes: depressive and anxiety disorders measured by psychometric instruments (S) Studies: cross-sectional, case-control, cohort studies; clinical trials	Case reports, reviews, comments, or basic studies Other oral diseases Other neurological and psychotic disorders rather than emotional disorders Absence of healthy control patients
Zheng et al. (50)	(P) Patients: subjects aged ≥ 14 years (E) Exposition: depression and anxiety disorders (C) Comparison: individuals without mood and anxiety disorders (O) Outcomes: periodontal disease (S) Studies: cross-sectional, case-control, cohort studies	Case reports or comments, meeting abstracts, basic studies Other oral diseases Mood disorders other than depression or anxiety Absence of periodontal healthy controls Insufficient data Publication language other than English or Chinese