Disorders originating in infancy/childhood

Reactive attachment disorder: It is a disorder caused by neglect or trauma in early childhood especially deprivation of maternal love and care or frequent changes in caregivers. As a result, the child suffers from failure to thrive and developmental delay. They become socially detached and may not survive. Affected children do not seek neither respond to comfort when distressed, are irritable and exhibit high-risk sexual behaviors, substance abuse and criminality as adults. Treatment is with psychotherapy.
Attention deficit/hyperactivity disorder: Attention-deficit/hyperactivity disorder (ADHD) is a disorder marked by an ongoing pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development. It has to occur in more than one setting e.g. home, school or work; with friends or relatives etc. 6 or more symptoms each from inattention and hyperactivity/impulsivity should be present for <16 year olds and 5 or more symptoms for >16 year olds. These symptoms should be present for at least 6 months.

Inattention means a person wanders off task, lacks persistence, has difficulty sustaining focus, and is disorganized; and these problems are not due to defiance or lack of comprehension. Examples are when a child/adult makes careless mistakes in schoolwork or at work; does not seem to listen when spoken to directly; does not follow through on instructions and fails to finish schoolwork; often loses things like pencils, books etc.
Hyperactivity means a person seems to move about constantly, including in situations in which it is not appropriate; or excessively fidgets, taps, or talks. In adults, it may be extreme restlessness or wearing others out with constant activity.
Impulsivity means a person makes hasty actions that occur in the moment without first thinking about them and that may have a high potential for harm, or a desire for immediate rewards or inability to delay gratification. An impulsive person may be socially intrusive and excessively interrupt others or make important decisions without considering the long-term consequences.