A Study of neuropsychiatric complications and Medication of Mentally Retarded Persons


No clear distinction is established between the intrinsic symptoms of mental retardation and its neuropsychiatric complications.  The problem is a difficult one both in terms of research and of diagnosis, and studies in this area have been inadequate so far.  One of the reasons for the difficulty of diagnosis is that, in psychiatry, the boundary between mental retardation and other entities of mental illness is unclear.  This study firstly aimed to determine the rate of neuropsychiatric complications in mentally retarded persons.

One hundred subjects were selected for this study from patients who visited the Social Welfare Center of Yokohama City for the Person with Mental Retardation between April 1999 and March 2000 for the purpose of consultations by Social Caseworkers and psychological and medical examinations.

The ages of the subjects range between 14 years and 53 years.  More than half (54%) of them were 17 or 18 years of age (people who were born in 1980 or 1981).  68 were male and 32 were female.  They are classified by the degree of mental retardation as follows: profound, 20 patients; severe, 18 patients; moderate, 30 patients; mild, 27 patients; borderline, 5 patients.

Complications were categorized into three types, namely, epilepsy, autism, and other neuropsychiatric symptoms.  Epilepsy was found in 39 patients.  19 patients were found to have complications involving autism.  In total, 67 patients had some complications.

The second aim of the study was to examine the use of medications for mentally retarded persons.  The study found that 14 patients were administered exclusively anti-epilepsy medication, and 21 patients were administered exclusively psychotropic drugs. 

The study highlighted that, the ratio of patients receiving anti-epilepsy medication increased as the degree of mental retardation became more severe.  On the other hand, psychotropic drugs were administered at very high ration in the borderline cases. 

In summary, the study found that 67% of mentally retarded patients had some neuropsychiatric complications.  Thirty-nine per cent were taking anti-epilepsy medication and/or psychotropic drugs.  Fourteen per cent of the subjects were taking anti-epilepsy medication exclusively.  When cases of co-administration with psychotropic drugs were included, the proportion was 18%.  Twenty-one per cent of the subjects were taking psychotropic drugs exclusively.  When cases of co-administration with anti-epilepsy medication were included, the proportion was 25%.

Another study in Japan have found similar result.  It can therefore be concluded that the above is a general proportion of mentally retarded patients who require medication.  Given the high proportion of mentally retarded patients with neuropsychiatric complications and the number of psychotropic drugs administered as a result, it is important that human resources to adequately cope with the situation are prepared.  The paper also proposes that measures and efforts to construct integral system of special education and medical care is needed.

(originally published on Journal of Disability and Medico-pedagogy Vol.10.2004: p11-12)