TABLE 1B.

Main characteristics of systematic reviews dealing with the association between periodontitis and depression: results (risk of bias, diagnostic criteria).

Results_included studies
References	Risk of bias assessment*	Diagnostic criteria for periodontitis	Diagnostic criteria for depression
Araújo et al. (48)	12/15 studies: low risk of bias 3/15 studies: high risk of bias	PD+CAL (4/7 studies) PD (7/7 studies) BOP (5/7 studies) Supragingival plaque (3/7 studies). Other: GI, PI gingival inflammation, subgingival calculus, number or present teeth… Less frequent: papillary bleeding index, approximal plaque index, bone loss in radiographs, vertical interproximal defects in panoramic radiographs, calculus, gingival recession, CPI, dental plaque, missing teeth, radiographic alveolar crestal height, gingival bleeding, periodontal index	10 different scales and inventories (geriatric depression scale, diagnostic and statistical manual for mental disorders, multidimensional coping inventory…)
Liu et al. (49)	14/14 studies: high quality (low risk of bias)	Chronic periodontitis (diagnosed by bleeding on probing, probing depth, clinical attachment loss, supragingival plaque, subgingival calculus, gingival bleeding, radiographic alveolar crest height, vertical bone defects >3 mm, number of standing teeth, GI, interradicular lesions etc.)	More than 20 different scales and inventories for anxiety and depression (brief symptom inventory, beck depression inventory, depression, anxiety and stress scale…) and self-reported depression
Zheng et al. (50)	Cross-sectional: 6/15 high risk of bias; 9/16 low risk of bias Case-control: 5/8 high risk of bias; 3/8 low risk of bias	CAL (>0, >2, ≥3, ≥4, ≥5), PPD (≥4, ≥5 ≥6), GI, PI, BOP, radiographic alveolar crestal height, CPI ≥3, panoramic radiography (>80% remaining bone), plaque control record, AAP, CDC, CI	Dichotomized. More than 20 different scales and inventories for anxiety and depression (brief symptom inventory, beck depression inventory, depression, anxiety and stress scale…) and self-reported depression

^*Newcastle–Ottawa scales with or without modifications.