“Forensic Clinical Psychology as an Emerging ... - SRM University

FORENSIC ISSUE OF MENTAL RETARDATION
DR.K. Rangaswami. M.A., DM & SP, Ph.D
FORMER DEAN AND PROF OF CLINICAL PSYCHOLOGY
S.R.I, SECUNDERABAD
Mentally retarded present a complex problem for the courts and correctional facilities. It is
estimated that although the prevalence of mental retardation is less than 1-2% of the population,
mentally retarded individuals represent 4-10% of those in the criminal justice system (Petersilia,
1997; Sundram, 1990). The deficits of mentally retarded individuals are not always readily apparent
to the forensic clinician. Many intellectually impaired go through the criminal justice system
without adequate attention to their unique needs. Mentally retarded individuals are at a distinct
disadvantage. Mentally retarded individuals are more likely to waive essential rights, to confess, to
go to trial, to plead guilty, (Goldman, 2001)
The disabilities are of these people commonly missed by the police, lawyers, and the correctional
system. Questions regarding competence and criminal responsibility are rarely raised, with those
individuals with mild retardation.
Definition of Mental Retardation: The American Association of Mental Retardation (AAMR,
2002) defines mental retardation as being characterized by sub average intellectual functioning
as indicated by an IQ that is at least two standard deviations below the mean of a given measure
of intelligence, which typically translates into a cutoff IQ score of approximately 70 on most
intellectual measures. Intellectual deficits alone are not sufficient for diagnosis but must also be
accompanied by limitations in adaptive skills deficits in the areas of social functioning, conceptual
skills, communication, and practical daily living skills, as indicated by performance on measures of
adaptive functioning that are two standard deviations, below the mean (AMMR, 2002).
The American Psychiatric Association’s definition of mental retardation is similar, requiring a threepronged
criterion of (1) an IQ less than 70; (2) deficits in adaptive functioning, and (3) onset before
age 18 (American Psychiatric Association [APA], 2000). However IQ scores can vary over time and
across situations and carry with them a degree of testing error (Kanaya et al., 2003).
The etiology of mental retardation is multifactorial and involves numerous risk factors. The AMMR
identifies four categories of risk for development of mental retardation (biomedical, social,
behavioral, and educational) that can occur across three time dimensions (prenatal, perinatal and
postnatal) (AMMR, 2002). Most of the mentally retarded individuals are in the mild range of mental
retardation, corresponding to IQ between 55 and 75. Individuals with mild mental retardation
usually do not have an outward sign of disability and appear to the general public as “normal”.
Severe forms of mental retardation are screened out because their intellectual deficits are obvious.
They have noticeable communication difficulties, and associated physical problems that are apparel
to the casual observer. In contrast, individuals with mild mental retardation may not be recognized
until the initiation of legal process.