BACKGROUND The term 'mental retardation' (MR) is outdated and has changed to 'intellectual disability' (ID). Unfortunately, this decision did not follow a nosology approach. The aim of this overview is twofold: (1) to provide a conceptual background and framing on the ID/MR field to other psychiatrists, and (2) to provide a nosology-based perspective to the debate on the name and concept of MR/ID. METHODS This conceptual paper is based on a literature review and on an iterative process of debate within the WPA Section 'Psychiatry of Mental Retardation'. RESULTS ID may be regarded not as a disease or as a disability but as a syndrome grouping (metasyndrome) similar to the construct of dementia. It includes a heterogeneous group of clinical conditions, ranging from genetic to nutritional, infectious, metabolic or neurotoxic conditions. The ID metasyndrome is characterized by a deficit in cognitive functioning prior to the acquisition of skills through learning. The intensity of the deficit is such to interfere in a significant way with individual normal functioning as expressed in limitations in activities and restriction in participation (disabilities). CONCLUSIONS The name 'developmental cognitive impairment' is here suggested to coexist with ID for naming the metasyndrome previously called MR following a polysemic-polynomious approach.