The prevalence of psychiatric disorders in the population with Intellectual Disability varies considerably between different studies; however, all studies consistently report a much higher prevalence than in the normal population. Furthermore, individuals that receive a precise diagnosis of a mental disorder represent only a small part of all disabled people that come in contact with a psychiatrist. Like anyone else, a person with Intellectual Disability can present with emotional, behavioral, interpersonal or adaptive problems that do not constitute a real psychiatric disorder, yet they can still benefit from seeing specialist.
The psychiatric diagnosis, already complex in the general population, becomes even more difficult in a person with Intellectual Disability, especially in more severe cases, where normal communication capacities are strongly limited or absent. The evaluation is always based on direct observation of behaviors and the person’s way of interacting with the outside world through the knowledge of precise meanings in the context of various environmental factors. The diagnostic uncertainty remains a very frequent problem that is often resolved with rapidity under pressure from the patients, their relatives, the operators, but also an excessive ease of doctors and psychiatrists to turn to pharmaceutical prescriptions. In the face of an ambiguous diagnostic analysis the sick person and his or her relatives are more concerned than ever, become anxious, the bureaucratic problems grow, and the care and assistance staff, devoid of rationale for intervention, loses effectiveness in their daily work.
One of the causes, or maybe the consequences, of such a misunderstanding of psychiatry is the lack of specific evaluation instruments, at both a national and international level.
The evolution of the psychiatric evaluation for Intellectual Disability retraces the same steps of general psychiatry, caught in the dichotomy between explanation and understanding, between subjective and objective, between change of thought and behavior.
The majority of instruments that have been produced to date are only applicable to subjects with more mild cases of Intellectual Disability, have a suggestive value, are not very sensitive, or are time consuming. The instruments that are used the most internationally are the DASH (Diagnostic Assessment for the Severely Handicapped), an evolution of PIMRA (Psychopathological Instrument for Mentally Retarded Adults) and the PAS-ADD (Psychopathological Assessment Schedule for Adults with Developmental Disability). In Italy, alongside the adaptation of PIMRA and DASH, the VAP-H (Psychopathological Evaluation for the Handicapped) and the SPAID (Psychiatric Instrument for the Intellectually Disabled Adult) were proposed.
The SPAID-G was created to minimize the limitations that other systems of structured evaluations have. The fundamental idea to its construction consists of the possibility to identify the psychiatric symptoms from an observational level, also in cases of more severe Mental Retardation. The SPAID is a complex system that includes a version for the preliminary evaluation of psychopathological area (SPAID-G), without any chronological limits in the survey of symptomatology, and area-specific modules which allow, on the basis of previous dimensional guidance, making a precise diagnosis in accordance with the criteria of DSM-IV TR. The 52 items that compose the “G” version are represented by descriptions of individual behavioral symptoms, attributable to the psychiatric diagnostic categories described in the DSM-IV TR.
Organic disorders (or somatic) are also more frequent in a person with Intellectual Disability than in the general population. The causes are traceable to a greater vulnerability, linked in turn to many factors which include the inadequacy of health resources, the difficulty of hygiene, congenital morpho-functional alterations, behavioral disorders. For the same reasons, there is also an increased sensitivity to the undesirable effects of drugs and of the other therapeutic interventions.
- Bertelli M., Scuticchio D., Ferrandi A., Bianco A, et al. Prevalence of psychopathological features in id: the italian SPAID multicentric study. Atti del VII Congresso Europeo Mental Health in Intellectual Disability (MH-ID) (Amsterdam 3-5 Settembre 2009), in press.
- Cooper S.-A. & Smiley E. (2009) Prevalence of intellectual disabilities and epidemiology of mental ill-health in adults with intellectual disabilities. In: Oxford Textbook of Psychiatry (ed. G. Goodwin). Oxford (in press).
- Cooper S.-A., Smiley E., Morrison J., Allan L. & Williamson A. (2007) Prevalence of and associations with mental ill-health in adults with intellectual disabilities. British Journal of Psychiatry 190, 27–35.