Severe, pervasive or chronic emotional/affective condition which prevents a child from performing everyday tasks. This condition is characterized by an inability to build or maintain relationships, inappropriate behaviors or feelings under normal circumstances, a pervasive mood of unhappiness or depression, or a tendency to develop physical symptoms or fears related to personal or school problems. Children may require special classrooms and teachers trained to help children with these special needs. School systems may have varying "levels" and processes for educational planning.
Source: Children Welfare Information Gateway