Table 1.

Summary of the included studies

Author / year / reference	Study place	Questionnaire	Sample size	Study design	Results	The score obtained from the Newcastle-Ottawa scale
1. Sahin (2019) [16]	Turkey	breastfeeding self-efficacy questionnaire Edinburgh depression questionnaire	357 breastfeeding mothers	Descriptive-analytical	The mean score of breastfeeding self-efficacy in women was 56.41 ± 8.97. Based on the EPDS total score, mothers who scored 12 or more. were classified as a risk group. 72 mothers (20.2%) are at higher risk of depression. Considering the increased risk of depression, it was found that women with depression have a lower breastfeeding self-efficacy score.	7
2. Zubaran et al(2013) [23]	Australia	breastfeeding self-efficacy questionnaire Edinburgh depression questionnaire	89 breastfeeding mothers	Cross-sectional	For the average breastfeeding self-efficacy, R2 = 0.123 The average score for breastfeeding self-efficacy was 63.51	6
3. Minamida et al(2020) [24].	Japan	breastfeeding self-efficacy questionnaire Edinburgh depression questionnaire	185 breastfeeding mothers	Cross-sectional	Self-efficacy is a protective factor for exclusive breastfeeding, while depression is a risk factor Depression has an inverse relationship with self-efficacy in breastfeeding (p < 0.500).	5
4. Mercan and Selcuk (2021) [19]	Turkey	breastfeeding self-efficacy questionnaire Edinburgh depression questionnaire	398 women aged 15–49 in the first 42 days of the postpartum period	A cross-sectional	The average breastfeeding self-efficacy score of mothers was 55.13 ± 8.9. There is a negative statistical relationship between BSES-SF and EPDS scores, so that breastfeeding self-efficacy decreases as postpartum depression increases. β = 0.194 for self-efficacy β = 0.114 for depression	6
5. Aslan and Ege (2016) [25]	Turkey	breastfeeding self-efficacy questionnaire Edinburgh depression questionnaire	265 postpartum women	Descriptive-Analytical	The average self-efficacy score of breastfeeding women is 58.92 ± 7.61 and the average score of the Edinburgh scale is 9.58 ± 5.10. The results of the study showed that one-third of mothers with a low breastfeeding self-efficacy score are at risk of developing depression symptoms.	6
6.Abuchaim ED (2018) [26]	Brazil	breastfeeding self-efficacy questionnaire Edinburgh depression questionnaire	208 women up to 60 days postpartum	Cross-sectional	Postpartum depression symptoms were present in 31.25% of women who presented medium (39.9%) and high (36.06%) levels of breastfeeding self-efficacy.	6
7. Vieira et al (2018) [27]	Brazil	breastfeeding self-efficacy questionnaire Edinburgh depression questionnaire	83 breastfeeding mothers	prospective cohort	self-efficacy is considered a protective factor for exclusive breastfeeding, while depression is a risk factor. Depression has an opposite relationship with self-efficacy in breastfeeding (p < 0.500).	5
8. Palancı and Aktaş (2021) [28]	Turkey	breastfeeding self-efficacy questionnaire Edinburgh depression questionnaire	254 mothers with babies aged 2–6 months	Cross-sectional	total mean Breastfeeding self-efficacy scores of mothers were 57.201 ± 7.612 And the average postpartum depression score was 8.516 ± 5.304. A significant relationship was found between breastfeeding self-efficacy and postpartum depression in mothers. R2 = 0.330 for breastfeeding self-efficacy R2=-0.338 for depression	5