**Breastfeeding and Active Bonding Protects against Children's Internalizing Behavior Problems**

**Jianghong Liu 1,\*, Patrick Leung 2 and Amy Yang <sup>3</sup>**


*Received: 4 October 2013; in revised form: 4 December 2013 / Accepted: 10 December 2013 / Published: 24 December 2013* 

**Abstract:** Breastfeeding is associated with numerous health benefits to offspring and mothers and may improve maternal-infant bonding. Ample evidence suggests breastfeeding can improve child neurodevelopment, but more research is needed to establish whether breastfeeding is linked to the development of child psychopathology. This paper aims to explore the effects of both breastfeeding and mother-child interactions on child behavioral outcomes at a later age. Children from the China Jintan Child Cohort Study (*N* = 1267), at age six years old were assessed, along with their parents. Children who were breastfed exclusively for a period of time in the presence of active bonding were compared to those who were breastfed in the absence of active bonding as well as to children who were not exclusively breastfed, with or without active bonding. Results from ANOVA and GLM, using SPSS20, indicate that children who were breastfed and whose mothers actively engaged with them displayed the lowest risk of internalizing problems (mean = 10.01, SD = 7.21), while those who were neither exclusively breastfed nor exposed to active bonding had the least protection against later internalizing problems (mean = 12.79, SD = 8.14). The effect of breastfeeding on internalizing pathology likely represents a biosocial and holistic effect of physiological, and nutritive, and maternal-infant bonding benefits.

### **1. Introduction**

Breastfeeding is associated with a wide range of positive health outcomes in children and mothers. For example, a systematic review and meta-analysis of approximately 400 studies found that breastfeeding was related to a reduced risk of acute ear infections, respiratory tract infections, asthma, obesity, type 1 and 2 diabetes mellitus, and childhood leukemia [1]. The production of prolactin and oxytocin during breastfeeding is associated with lower levels of maternal stress and enhanced bonding [2]. Furthermore, early cessation of breastfeeding or not breastfeeding at all has been linked to an increased risk of maternal postpartum depression [1].

One particular outcome of interest is that of cognitive development in breastfed children. Breast milk is rich in vital nutrients, such as essential fatty acids, vitamins, minerals, and amino acids, that are associated with improved cognitive functioning [3], language development [4], and overall neurological development [2,5]. In addition, breastfeeding has been associated with improved mother-infant bonding [6,7]. For instance, early feeding interactions between mother and infant may result in more positive feeding experiences and produce greater maternal sensitivity and responsiveness to infant needs [8].

Although previous studies have indicated a wealth of nutritional, physiological, and cognitive benefits to children from breastfeeding, little has been done on emotional development and regulation. It is known that childhood internalizing disorders, including depression and anxiety, can affect up to about 20% of children and adolescents [9]. They also increase the risk of future psychopathology in adulthood [10]. The identification of readily modifiable factors, such as breastfeeding, that may protect against childhood internalizing behaviors is therefore important. Studies have not yet found a relationship between breastfeeding and behavioral outcomes during early childhood [11,12]. However, there are limited studies conducted in older age groups. Oddy *et al*. found that breastfeeding may be associated with adverse mental health outcomes in early adolescents while Kwok *et al*. found inconsistent associations [13,14]. However, few studies have tested the long term effect of both breastfeeding as well as the mother-infant interaction during feeding on child behavioral outcomes.

The purpose of this study is to examine whether breastfeeding was related to fewer internalizing disorders later in childhood in a large, community-based sample of Chinese children and parents, and to understand whether breastfeeding and active bonding (*i.e.*, verbal interactions during feeding) were associated with the reduced risk of internalizing behaviors. Finally, this study will assess whether there was any breastfeeding duration (or dosage) effect on internalizing behaviors.

#### **2. Experimental Section**
