A child showing no concern when interacting with strangers may be experiencing which disorder?

The behavior exhibited by a child showing no concern when interacting with strangers aligns with the characteristics of Disinhibited Social Engagement Disorder. This disorder is specifically characterized by a pattern of behavior in which a child interacts with unfamiliar adults in a culturally inappropriate or overly familiar manner, typically including a lack of inhibition in approaching strangers.

Disinhibited Social Engagement Disorder occurs in children who have experienced insufficient care, such as neglect or abrupt separation from caregivers, leading to disturbances in attachment. Unlike other disorders, this condition emphasizes the child's indiscriminate friendliness and lack of wariness around unfamiliar individuals, indicative of underlying attachment issues.

In contrast, Reactive Attachment Disorder involves significantly impaired social and emotional behaviors and typically presents with withdrawal or a lack of responsiveness to caregivers, rather than overt friendliness with strangers. Adjustment Disorder relates to emotional or behavioral symptoms arising in response to a stressful life event, and Prolonged Grief Disorder is characterized by intense mourning and grief following the death of a loved one, not by unusual social behaviors with strangers. Hence, Disinhibited Social Engagement Disorder is the most accurate diagnosis for the behavior described.