Retrospective investigation of medico-legal autopsy cases involving mentally handicapped individuals.

Mentally handicapped individuals were involved in some way in 64 (17.7%) of the total of 362 medico-legal autopsy cases during the past 13 years. Among these 64 cases, 32 were suicides committed by mentally handicapped persons (18 males and 14 females). The most common method of suicide was drowning (65.6%). Five cases were homicides suddenly and unexpectedly committed by mentally handicapped persons. In four of the five cases, the victim was a member of the assailant's family; this was considered to be a characteristic of homicides committed by mentally handicapped persons. On the other hand, there was only one case in which a mentally handicapped person was victimized, that of a 34-year-old female with schizophrenia who was strangled by her mother. In 19 cases, infanticide was committed by mentally handicapped mothers ranging in age from 17 to 40 years old; approximately 80% of the infanticide victims were infants of less than 6 months, and this was the age range most at risk of victims. There were two cases involving either double suicide or murder followed by suicide; in one case, the 45-year-old mother of a mentally handicapped 18-year-old son with congenital hydrocephalus set fire to her own house, and both perished in the fire, and in the other, a 65-year-old schizophrenic female fatally stabbed her neighbor, a 68-year-old female, and then she also cut herself fatally. There were three cases in which mentally handicapped individuals died due to freezing, and one in which an epileptic died suddenly due to status epilepticus. In order to prevent these tragic events, at first, it is necessary to much better understand the circumstances of the mentally handicapped individuals and their families without prejudices against them. The authors propose that a more comprehensive psychiatric medical care including the following systems should be established in Japan: 1) Day care for the mentally handicapped person, especially after the discharge as well as during admission, and support for their relatives, 2) Therapeutic drug monitoring to assess the effective level of psychotropic drugs and to suppress the side effects in the patients receiving the psychotropic drugs for a long time.