In-patient care for people with a learning disability and a mental illness

People with the dual diagnosis of mental illness and mental retardation have proved difficult to resettle from hospital. Yet there is considerable evidence that, if diagnosed correctly, treatment for such patients can be effective (e.g. Matson, 1981; Welch & Sigman, 1980).Thispaper describes the outcome of treatment at a specialist unit for patients with dual diagnosis.

used infrequently. The unit has sessional time from a neurophysiologist and an EEC techni cian, who are able to obtain EEC recordings from even the most disturbed patients.
Dr Hurst and Dr Nadarajah separately re viewed case-notes for all 157 first admissions to the unit between May 1983 and February 1991, and assigned diagnoses using DSM-1II-Rdefini tions (with agreement on the diagnoses of all but two patients). Outcome at discharge was jointly assessed using a four-point scale: 1. relief of presenting disorder; 2. improvement of present ing disorder; 3. no change in presenting disorder; and 4. worsening of presenting disorder.

The patients
The 157 patients included 97 men and 60 women. Ages on admission ranged between 15 and 63 years, with a mean of 30 years. Two thirds (66%) were assessed as having mild mental retardation using DSM-111-Rcriteria, with 30% having moderate mental retardation, and 4% with a borderline mental retardation . Over a quarter (27%) of patients had epilepsy, and 29% had chromosomal abnormali ties or neurological disorders, including 15 with chromosomal abnormalities (nine of the sex chromosomes and six of autosomes), seven with neurological abnormalities from birth (including tuberous sclerosis), six with histories of infection (including encephalitis), eight with motor abnor malities (including hemiplegia and cerebral palsy), four with histories of trauma, and five with associated sensory impairments.
The main psychiatric diagnoses on Axis I are shown in Table 1. The most common were schizophrenia (29%), mood disorders (21%), other psychotic disorders (8%), and sexual dis orders (6%). Patients with mood disorders com prised 16% with bipolar affective psychoses, 1% with dysthymia, and 4% with depressive dis order. The group with other psychotic dis orders comprised two patients with delusional (paranoid) disorders, one with a brief reactive psychosis, and six with atypical psychosis. Small numbers had intermittent explosive disorder (4), adjustment disorder (4), organic personality dis order (3), organic delusional disorder (1), alcohol abuse (1), psychoactive substance abuse (1), Tourette's disease (1), overanxious disorder (1), and obsessive compulsive disorder (1). Three per cent had unspecified mental disorders, and a quarter of the patients (24%) had no diagnosis on Axis I. The latter comprised 11% with a main diagnosis of mental retardation, and 13% with other diagnoses including complex epilepsy, aggressive behaviour requiring assessment, and emergency admissions following a social crisis. There was no association between diagnosis on Axis I and degree of mental retardation, with the exception of bipolar affective disorder which was strongly associated with mild mental retardation.
Nine per cent of patients had diagnoses of personality disorder as their main psychiatric disorder, and a further 22% as a secondary diag nosis. Table 2 shows that the main types of personality disorder were antisocial (14), schizoid (9), and dependent (9). Other disorders on Axis II included 14 patients (9%) with autism, and a further six (4%) with other pervasive devel opment disorders.
Three-quarters (75%) of the patients were admitted directly from the community, with the remainder transferred from other hospitals (18%) or admitted through the courts (7%). Twenty per cent were detained under the Mental Health Act either on admission or during their stay in the unit. Almost a third (31%) of admissions were precipitated by physical aggression to others, or were followed by aggressive episodes during the in-patient stay. Physical aggression was more common among men, patients with a diagnosis of personality disorder or epilepsy, or with no diagnosis on Axis I. Physical aggression was least evident among patients with schizophrenia and bipolar affective disorders.
Median length of stay was 68 days, and during the eight years covered by the survey, the unit had a total of 34,980 occupied bed-days, equiva lent to 12 occupied beds/day (or a total of 14 beds when an allowance is made for occupancy rates).

Outcome
All but two of the patients had been discharged at the time of the survey, with 63% relieved of their presenting disorder, 25% improved, 11% not changed, and 1% with a presenting disorder which had worsened. There were no deaths or suicides. Outcome was particularly favourable among patients referred from general psychiatric units, and unfavourable among patients with pervasive developmental disorder, or borderline mental retardation (who tended to resent being placed among people with more pronounced disabilities).
The great majority (94%) were placed in the community, with the remainder returning to the psychiatric or mental handicap hospital which had originally referred them. Over a third (37%) of patients were re-admitted, of whom 62% had one re-admission and the remainder had multiple re-admissions. Re-admission was less frequent among patients with borderline mental retardation and among women, and more fre quent among patients with pervasive develop ment disorder or mild mental retardation.

Comment
Recent studies have demonstrated that stan dardised psychiatric classifications and diag nostic instruments can be used validly for people with a mild or moderate learning disability (Pawlarcyzk & Beckwith, 1987;Meadows et al, 1991;Ballinger et al, 1991). Complexity of diag nosis and the distinctive presentation of psychi atric disorders among these patients indicates a need for a specialist service. The experience of operating such a service is that many of its patients who have failed to respond to treatment by general psychiatric services respond well to an environment which is attuned to their distinctive communication skills. Siting a specialised unit of this kind near other specialist services for people with mental retardation provides easy access to specialist treatment, daycare and recreational facilities, but it is essential to maintain good working relationships with local mental illness services, to share treatment facilities and develop staff skills in work with mentally ill people.