Table 5.

Overview of results: contact frequency and depression

Author	Depression measure	Social network measure	N a	Results b	Quality
Cross-sectional studies
Becker et al., 2019 [83]	Euro-D	Contact index: contact with each person in network over the last 12 months (daily, several times a week, about once a week, about every two weeks, about once a month, less than once a month, never)	52,513	+	Poor
Blumstein et al., 2004 [35]	CES-D (20)	Weekly contact with friends Weekly contact with children	1290	+   +	Poor
Castro-Costa et al., 2008 [143]	GHQ-12	Weekly frequency of visits from offspring, relatives and friends	1510	0	Poor
Chi & Chou, 2001 [87]	CES-D (20)	Contact frequency with relatives Contact frequency with friends (Less than once a month, once a month, two to three times a month, once a week, two to six times a week, everyday)	1106	+  0	Good
Domènech-Abella et al., 2017 [89]	CIDI 3.0	Contact with network members at least once per month in the previous 12 months	3535	0	Good
Ermer & Proulx, 2022 [91]	CES-D (11)	Contact with network member (every day, several times a week, once a week, once every two weeks, once a month, a couple times a year, once a year, and less than once a year)	865	0	Fair
Forsman et al., 2012 [144]	GDS-4	Contact frequency with friends Contact frequency with neighbors (Frequent contact: several times a week, several times a month; infrequent contact: few times a year, never, does not exist)	6838	+   +	Good
Jeon & Lubben, 2016 [97]	CES-D (20)	Contact frequency with non-kin Contact frequency with kin (Less than once a month, monthly, 2–3 times a month, weekly, 2–3 times a week, daily)	424	0  +	Fair
La Gory & Fitzpatrick, 1992 [145]	CES-D (20)	Contact scale: visiting friends and relatives, being visited by them, phoning or writing them and meeting them in a social setting	725	+	Poor
Lee et al., 1996 [99]	CES-D (20)	Contact frequency with children Contact frequency with friends (Monthly or less, almost weekly, almost daily)	162	+   +	Poor
Li et al., 2019 [100]	PHQ-9	Average contact frequencies that a participant talked to network members in the past one year (less than once a year to every day)	3157	0	Fair
Litwin & Levinsky, 2022 [146]	Euro-D	In-person contact Electronic contact (daily, several times a week, about once a week, less often, never)	33,403	+  0	Good
Litwin & Levinsky, 2023 [101]	Euro-D	Contact to confidants (7-point scale: 1 = never; 7 = daily)	35,145	+	Good
Litwin et al., 2015 [102]	Euro-D	Contact frequency (never to daily) to network persons	25,245	0	Good
Marshall & Rue, 2012 [147]	CES-D (20)	Index of contact frequency to family members/ friends/ church members (never to nearly every day)	1108	+	Good
Marshall-Fabien & Miller, 2016 [148]	CES-D (12)	Index of contact frequency to family members/ friends/ church members (never to nearly every day)	1108	0	Good
Minicuci et al., 2002 [103]	CES-D (20)	Personal contact with family members Telephone contact with family members (never, every 6 months, every 2–3 months, every month, more often)	2398	0 0	Good
Palinkas et al., 1990 [64]	BDI (18)	Frequency of face-to-face contact with close family and friends (at least once a week vs. less than once a week)	1615	0	Poor
Pilehvari et al., 2023 [105]	CES-D (20)	Contact to people that immediately surround them (0 = have never spoken to each other to 8 = every day)	1170	0	Good
Taylor et al., 2018 [149]	CES-D (12)	Contact frequency with family members and friends (no isolation: nearly every day, at least once a week, a few times a month; isolation: at least once a month, a few times a year, hardly ever or never) to combination variable (objectively isolated from both family members and friends, objectively isolated from family only, objectively isolated from friends only, not objectively isolated from family and friends)	1439	0	Good
Vicente & Guadalupe, 2022 [107]	GDS-15	Contact frequency (1 = a few times per year to 5 = daily)	612	0	Poor
Wu et al., 2017 [150]	CES-D (20)	Interpersonal contacts over the past year (dichotomized: poor social support was defined as ≤ 1 episode of contact with neighbors, relatives, or friends per month)	5635	+	Good
Longitudinal studies
Blumstein et al., 2004 [35]	CES-D (20)	Weekly contact with friends Weekly contact with children	746	0 0	Good
Bui, 2020 [19]	CES-D (11)	Contact frequency with named alters (less than once a year to every day)	2200	0	Good
Chao, 2011 [109]	CES-D (10)	Contact frequency (mean frequency of meeting with children who were not living with respondent; never or not available to everyday)	4049	+	Good
Gan & Best, 2021 [141]	CES-D (8)	In-person contact with friends Tele-conversation with friends Contact with neighbors (Less than once a month to three or more times a week)	3105	0 0 0/ +  (+ only in average outcome profile)	Fair
Husaini, 1997 [142]	CES-D (20)	Contact frequency with friends Contact frequency with relatives (Daily to once a year)	1200	0/ +  0/ +	Poor
Schwartz & Litwin, 2017 [116]	Euro-D	Contact frequency to alters (daily to never)	14,101	0	Good

^an: Sample size, baseline sample was used in longitudinal studies

^bResults: 0 indicates no sig. relationship (p ≥ 0.05), + indicates sig. relationship (p < 0.05)

Depression measures: BDI Beck Depression Inventory, CES-D Centre of Epidemiologic Studies Depression Scale, CIDI Composite International Diagnostic Interview, EURO-D EURO geriatric depression scale, GDS Geriatric Depression Scale, GHQ General Health Questionnaire, MADRS Montgomery–Åsberg Depression Rating Scale, PHQ-9 Patient Health Questionnaire