Aideen Mary Naughton of Public Health Wales, in Pontypool, England, and colleagues conducted a systematic review of 42 studies of children from age 1 month to age 6 with confirmed neglect or emotional abuse who had emotional, behavioral and developmental issues recorded.
The study, published in the Journal of the American Medical Association's Pediatrics, found key features in the neglected or abused child included aggression, withdrawal, passivity, developmental delay, poor peer interaction, transition from ambivalent to avoidant insecure attachment patterns, passive to increasingly aggressive behavior and negative self-image.
The review also found emotional, brain and language function deteriorated in these children without intervention.
"Lifelong consequences of parental neglect and abuse include physical and mental health problems; impairment in language, social and communication skills; and severe effects on brain development and hormonal functioning," the researchers said in a statement. "Early intervention has the potential to change children's lives."
Notable deaths of 2014 [PHOTOS]