Reactive attachment disorder can start in infancy. There's little research on signs and symptoms of reactive attachment disorder beyond early childhood, and it remains uncertain whether it occurs in children older than 5 years.

Signs and symptoms may include:

• Unexplained withdrawal, fear, sadness or irritability
• Sad and listless appearance
• Not seeking comfort or showing no response when comfort is given
• Failure to smile
• Watching others closely but not engaging in social interaction
• Failing to ask for support or assistance
• Failure to reach out when picked up
• No interest in playing peekaboo or other interactive games

To feel safe and develop trust, infants and young children need a stable, caring environment. Their basic emotional and physical needs must be consistently met. For instance, when a baby cries, the need for a meal or a diaper change must be met with a shared emotional exchange that may include eye contact, smiling and caressing.

A child whose needs are ignored or met with a lack of emotional response from caregivers does not come to expect care or comfort or form a stable attachment to caregivers.

It's not clear why some babies and children develop reactive attachment disorder and others don't. Various theories about reactive attachment disorder and its causes exist, and more research is needed to develop a better understanding and improve diagnosis and treatment options.

The risk of developing reactive attachment disorder from serious social and emotional neglect or the lack of opportunity to develop stable attachments may increase in children who, for example:

• Live in a children's home or other institution
• Frequently change foster homes or caregivers
• Have parents who have severe mental health problems, criminal behavior or substance abuse that impairs their parenting
• Have prolonged separation from parents or other caregivers due to hospitalization

However, most children who are severely neglected don't develop reactive attachment disorder.

Without treatment, reactive attachment disorder can continue for several years and may have lifelong consequences.

Some research suggests that some children and teenagers with reactive attachment disorder may display callous, unemotional traits that can include behavior problems and cruelty toward people or animals. However, more research is needed to determine if problems in older children and adults are related to experiences of reactive attachment disorder in early childhood.