Developmental disabilities is a generic term that refers primarily to mental retardation and some of the pervasive developmental disorders. Mental retardation is characterized (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition--DSM-IV) by significantly below average intellectual functioning which has its onset before the age of eighteen years and is accompanied by significant impairment in adaptive functioning. The pervasive developmental disorders are characterized by significant impairment in multiple areas of development, particularly social interaction and communication, and accompanied by stereotyped behaviour, interests or activity.
School psychologists, by virtue of their knowledge of normal child development and assessment techniques, play an important role in the diagnosis of developmental disabilities. Ongoing support can include counselling of parents and siblings, offering parent workshops, social skills programmes, professional training for teachers, developing behavioural interventions, providing direct counselling and advocacy to students, and liaising with community agencies and the medical profession.
Psychological Services of the Toronto District School Board has developed a Psychological Assessment Checklist for Developmental Disability outlining best practice for the assessment and diagnosis of this condition. This document is in PDF format, and requires the Adobe Acrobat Reader to be opened. If you do not have this program, you can download a free copy from www.adobe.com.