Developmental impact of child neglect in early childhood

Child neglect, often overlooked, is the most common form of child maltreatment. Most perpetrators of child abuse and neglect are the parents themselves. A total of 79.4% of the perpetrators of abused and neglected children are the parents of the victims, and of those 79.4% parents, 61% exclusively neglect their children. The physical, emotional, and cognitive developmental impacts from child neglect in early childhood can be detrimental, as the effects from the neglect can carry on into adulthood.
Physical health development.
Research has shown that by the time a child reaches the age of six, if they have experienced adverse exposures, such as neglect, their chances of having overall poor physical health increases by two-fold. Infants can develop poor physical health if neglect starts even before the child is born. A child deprived of basic necessities, such as proper prenatal care, is at risk of being born prematurely or having complications during birth.
Non-organic failure to thrive.
A common outcome of neglect is non-organic failure to thrive in infants and children. "Non-organic" simply means that the child's failure to thrive cannot be explained by an organic cause, such as an illness or deficiency. Failure to thrive is a term that is typically used to describe a child with an abnormal pattern of weight gain or weight loss, or experiencing insufficient growth patterns in accordance with a child's age and developmental stage. These conditions can arise when a child does not receive adequate nutrition or necessary medical attention required for proper physical growth and development. Neglect can play a role in non-organic failure to thrive because children who experience neglect are often malnourished, not receiving proper nutrients, which hinders their physical growth and development. The most common symptoms of non-organic failure to thrive are insufficient weight gain or growth in height, and these common symptoms can affect a child over his/her life course by setting them back in weight class and can hinder their overall growth. Other symptoms of failure to thrive include symptoms such as anemia, iron deficiency, low insulin, dry/cracked skin, thin hair growth, pasty skin, and more. And in more extreme cases, non-organic failure to thrive can affect a child over their whole life course by actually damaging his/her cognitive development and his/her immune system due to insufficient calorie intake or lack of medical attention, making the child much more likely to miss developmental milestones and much more prone to illness even later into adulthood.
Social and emotional development.
Attachment and avoidance of intimate relationships.
A developing child requires proper nutrition, protection, and regulation for healthy attachment. About 80% of neglected children display attachment disorder symptoms and eventually form insecure attachments to their caregivers as a result of caregivers' unresponsive interactions. This disturbed attachment to their primary caregiver alters future relationships with peers by becoming emotional and physically isolated from others reducing the likelihood of forming emotional connections. Moreover, as a result of their past maltreatment, neglected children feel that forming intimate relationships with others loses their control in life and exposes them by increasing their vulnerability. There are quite a few varying aspects that create a neglectful environment, however, one that is quite common is having parents that are substance users. With parents who are addicted to drugs, children's basic needs are not met when parents are attempting to obtain their drugs as well as when they take them. This can create a weak parent-child relationship that is more likely to result in insecure attachment relationships as well as poor parenting practices. This example is one of many scenarios where neglect can affect a child's development especially in how they form relationships with others.
Emotional deregulation.
Neglected children demonstrate lack of emotional regulation, understanding emotional expressions by others, and difficulty in distinguishing emotions. When posed with problem-solving tasks, neglected children reacted with anger and frustration, and were less enthusiastic with completing a new task. Neglected children often have distressing memories of their past to which they regulate their emotions by suppressing them.
Psychiatric development.
Childhood abuse and neglect can lead to developing posttraumatic stress disorder (PTSD), depression, and anxiety disorders later in life. Although major depression is not readily seen in younger children compared to adolescents, it is still prevalent. While psychological consequences of childhood neglect will vary considerably among individuals, the frequency and duration of the maltreatment ultimately determines the severity of its impact in adulthood.  Persisting mental health problems are a common result of child abuse and neglect in adults. Mental health problems associated with past histories of child neglect include personality disorders, dis-associative disorders, and psychosis.  Major depression, a prevalent finding in adults who experienced childhood neglect are found to be six times more likely to develop post traumatic disorder than adults who did not have such experience. This consequence is significantly increased if there is a co-morbidity of parental divorce. Maladaptive behaviors such as alcohol and substance abuse, emotional homelessness and unhealthy social and emotional relationships are also linked, as such behaviors are used as a means to cope and self medicate the void that resulted from specific forms of parental abuse and neglect. Low self-esteem and low self worth are also consequential as those that suffer from neglect often feel unworthy and develop competing needs for affection and acceptance.
Cognitive and academic development.
Neuroimaging studies using magnetic resonance imaging have shown that the brain structure of a neglected child is significantly altered. The overall cerebral volume of the brain of a neglected child is significantly diminished, with a reduced midsagittal area of the corpus callosum, and the ventricular system is enlarged thereby resulting in decreased cognitive growth, development, and functioning. Further studies show that neglected children have poor cerebral hemisphere integration and underdevelopment of the orbitofrontal cortex region which affects the child’s social skills.
Studies on academic progress in neglected children have indicated that these children may experience a drop in their academic performance. Children who have experienced neglect are more likely to have attention deficits and poorer academic achievements. Further, neglect in early childhood can result in a rise in stress levels in the child. Elevated stress levels from neglect can lead to a release of higher levels of cortisol causing damage to the hippocampus which can affects a child’s learning and memory.
A study examining the motor, language, and cognitive development of neglected children showed that the scores from the Bayley Scales of Infant Development were significantly lower than non-maltreated children. Neglected children displayed poor self-control and a lack of creativity in solving problem. Standardized tests become a challenge for neglected children as they perform poorly on intellectual functioning and academic achievement. Further, neglected children perform significantly poorer on IQ tests than non-maltreated children.