NADD Bulletin Volume I Number 1 Article 2

Complete listing

Childhood Schizophrenia in the Developmentally Disabled

Pauline Lee, Ph.D., Robin Friedlander, M.D., and Christina Donnelly, R.N.

Schizophrenia and the Developmentally Disabled

The diagnosis of schizophrenia in the developmentally disabled has been the focus of much debate and discussion for many years. Some of the questions that have fuelled the debates include: “Does one diagnosis negate the other? Can the two co-exist? Are they the same entity in a different form? Is there a peculiarity of symptoms? Is there an increased prevalence of either condition with the other? Does their association throw any light on their respective aetiologies, especially that of schizophrenia?....” (p.301, Turner, 1989).

The nineteenth century saw the beginnings of the conceptualisation of schizophrenia. Kraeplin delineated “dementia praecox” as consisting of hallucinations, delusions, negativism, attentional problems, stereotyped behavior and emotional disturbances. He described three types of schizophrenia: Catatonia, hebephrenia and paranoid type. Kraeplin also proposed that approximately 7% of cases of dementia praecox arose on the basis of “idiocy” and subsequently suggested an early form of psychosis “pfropfschizophrenia”, an engrafted schizophrenic psychosis of particularly early onset. He maintained that “certain forms of idiocy with developed mannerisms and stereotypies might be early cases of dementia praecox”. Blueler preferred the term “schizophrenia” over “dementia praecox”. He disagreed with Kraeplin’s views. Blueler believed that the stereotyped forms of movement of idiots was basically different from catatonia and that in idiocy a number of other diseases were involved that were different from schizophrenia. Others argued that “mental deficiency” was largely caused by the same factors as those responsible for schizophrenia/dementia praecox.

In the 1930s the research focused more in the area of genetics and obtaining estimates of the true prevalence of dual diagnosis. Penrose (1938) reported from his study of 1,280 developmentally disabled patients that there were only 48 individuals with schizophrenia (under 4%). Kallman, Barrerra, Hoch, Kelly (1940-1) reported from twin and family studies that there was not an increase in the frequency of “mental deficiency” among blood relatives of schizophrenia or of an increase incidence of schizophrenia in the offspring of “feeble minded patients”. He concluded that the “endogenous forms of schizophrenia and mental deficiency are based on different genetic factors”.

In the 1970s Reid and Heaton-Ward reported in independent studies that schizophrenia in the developmentally disabled could be diagnosed on the basis of usually accepted criteria, but stated that this diagnosis was impossible to make in individuals who were unable to communicate verbally.

The changes in nomenclature and inexact diagnostic criteria over the past fifty years led to schizophrenia being over diagnosed in North America. With the publication of the Diagnostic and Statistical Manual of the American Psychiatric Association, Third Edition (DSM-III) in 1980 there was now more stringent criteria available enabling clinicians to make more reliable and valid diagnoses. Currently, clinicians agree that schizophrenia occurs in the developmentally disabled and believe that it is clinically similar to persons with normal intelligence. However, there is a current tendency in North America to make schizophrenia a diagnosis of exclusion because of the historical over diagnosis of this disorder. Furthermore, many clinicians believe that it is nearly impossible to assess the presence of psychotic symptoms in individuals with moderate or greater developmental disabilities or who are nonverbal (Sovner and DesNoyes Hurley, 1989). It has been noted that in individuals with moderate or greater developmental disabilities there is a danger to interpret any evidence of disorganized behavior or thinking as a sign of psychosis, often leading to an over diagnosis of psychosis and under recognition of anxiety and depression (Sovner and DesNoyes Hurley, 1989).

Early Onset Schizophrenia

The first documentation of psychoses in children appeared in a textbook in 1874 by Henry Maudsley when he described “insanity in early life” (Kanner, 1973). A further reference appeared in 1883 by Spitzker who described infantile psychosis as rare and caused by heredity, fright, sudden changes of temperature or masturbation (Kanner, 1973). In 1906 De Santis applied dementia praecox to children and coined the term “dementia praecocissa” to reflect the early onset. He reported that not only children who are developmentally disabled display psychotic behavior but others who are not may also show the early onset of psychosis. The term “dementia praecocissa” was later abandoned as it began to be used too broadly to describe other unrelated disorders (Turner, 1989).

In the 1930s Potter introduced the diagnosis of “infantile schizophrenia” to describe children with a loss of interest, disturbances of thought, lack of emotional rapport, diminution and distortion of affect and changes in mobility with a tendency to develop stereotypies. In 1943 Kanner identified the syndrome of “infantile autism”. Other clinicians reported subtypes of schizophrenia such as “symbiotic psychosis” and “nonorganic types” Most clinicians of the time preferred to use the diagnosis “childhood schizophrenia” to describe children who had onset of psychotic symptoms in childhood. Eventually, children with autism, schizophrenia, organic mental disorders were all grouped under the broad classification of “childhood schizophrenia”. This designation was finally removed from the classification system with the publication of the ICD-9 and DSM-III in 1979/80. This change was largely influenced by the work of Kolvin (1971) who demonstrated the similarity between child and adult schizophrenia and how adult criteria could be applied to children. In addition, there was the introduction of the term Pervasive Developmental Disorder (PDD) to refer to what we know of today as Infantile Autism and other Autistic Spectrum Disorders.

Traditionally, the term “childhood schizophrenia” referred to children who were prepubertal and developed schizophrenia. However, the term “prepubertal” refers to a biodevelopmental state which cannot be defined exactly by age (Werry, McClellan, and Chard, 1991). A similar problem with inexact definitions also applied to the term “adolescent schizophrenia”. In response to the lack of precise definitions, Werry proposed the use of the terms “Early Onset” (EO) to describe childhood and adolescence onset schizophrenia between the ages of 13 and 17 years and “Very Early Onset” (VEO) to refer to the onset of schizophrenia before 13 years of age.

Reviewing the literature on early onset schizophrenia is complicated. Its rarity, in combination with changes over the years in nomenclature and diagnostic criteria has led to little systematic research focused on early onset schizophrenia. Since the early 1990s there have been a number of important papers published indicating that early onset schizophrenia is a variant, differing only quantitatively from the adult disorder in the following variables: 1) male predominance; 2) higher rate of insidious onset; 3) more neurodevelopmental abnormalities; 4) more maladaptively “odd” personalities, 5) greater resistance to antipsychotic drug treatment, 6) poorer outcome, 7) less differentiated symptomatology and 8) increased family history of schizophrenia (Werry et al., 1991).

In children with developmental disabilities there is an even greater paucity of research and there have only been a few reports describing early onset schizophrenia in the developmental disabled population.


The following information represents preliminary findings from an ongoing study. The data is based on ten children with developmental disabilities and early onset schizophrenia who were seen by a community-based mental health team specialising in individuals with dual diagnosis. Several variables were examined, and despite the small sample size, these will help both to define the characteristics of the disorder in children with developmental disabilities and to give some indication of prognosis and response to treatment.

Diagnostic Issues

It is generally accepted that schizophrenia can be diagnosed in individuals with developmental disabilities using the DSM-IV criteria. Although the illness is similar in form to its psychopathological presentation in the general population, it is somewhat different in that the psychopathology is less complex.

Certainly, most clinicians would agree that schizophrenia can be diagnosed in individuals with mild to moderate developmental disabilities (IQ - 50-70) and who have a reasonable degree of verbal fluency. Andrew Reid in the United Kingdom has written a lot about his theoretical concept of schizophrenia in the developmentally disabled. He has argued that schizophrenia has firmly rooted language based phenomenonology and that a certain level of intelligence is required for the individual to be able to describe the key symptoms. Consequently, he has advocated that a diagnosis of schizophrenia can only be established with any degree of conviction in individuals with developmental disabilities who have an IQ of above 45 (that is, at least in the upper end of the moderate range).

However, even individuals with mild developmental disabilities can show limited verbal competence and inevitably this makes interviewing difficult. In this clinic based sample most of the children showed premorbid intellectual abilities in the mild range. There were two children with premorbid intellectual abilities in the moderate range. For most of the children, when we saw them their communication abilities had deteriorated and were very limited. However, some children were able to describe, albeit simply, their symptoms. For example, if the children were asked if they hear any voices when they are alone, some of the responses that were provided included: “I hear silly voices”, “My head is buzzing”, “I hear drums”. Often the children were unable to provide further detail. However, for some children, it was extremely difficult to elicit verbal descriptions of their symptoms. Contrary to Reid’s position, while some of the children were not able to describe their symptoms, we were able to make the diagnosis of Early Onset Schizophrenia according to DSM-IV criteria by using the following data collection sources:

1.Detailed developmental history of individual to provide evidence of marked change in behavior.

2.Teachers and parents observations of behavior and recent changes.

3.Review of family history of mental illness.

4.Clinical evidence of hallucinations.

Presentation of Symptomatology

With all of the children the hallucinations and delusions were simple in nature and the subtypes were similar to those reported in the general population of children with early onset schizophrenia. All of the ten children showed evidence to suggest auditory hallucinations and the most common type was of a “commenting type” where the children often reported to hear voices swearing.

Examples of hallucinations:

Command: “Do not tell anyone you hear voices”

“Light a fire in the room”

Conversing:“I hear voices talking to Phil Collins”

Commenting:“The voices say bad things”

None of the children reported visual or other types of hallucinations without describing auditory hallucinations. There were seven children who were found to have visual hallucinations and often they were more inferred by their behaviour than by verbal descriptions. Some examples of visual hallucinations were: a child would look at a corner of the room as if something was there, waving to people not present, looking over her shoulder as if someone was there, and grabbing at things in the air. Of the children that were able to report visual hallucinations one child reported that he saw Jesus and another child reported that he saw spiders on tiles.

Of the ten children, five reported delusional thinking and they were simple in nature. They were similar to those found in younger children with very early onset schizophrenia in the general population which tend to be less complex and less fixed. The most common reported delusions were persecutory. Some examples included: thinking people are going to do him harm, thinking his food was being poisoned, thinking people were following him in cars and thinking the furniture and fruit were dangerous.

It was difficult to assess formal thought disorder primarily because of the reduction in the children’s ability to express things verbally which was related to their developmental disability. However, there was one child who showed prominent features of thought disorder where there was marked illogical thinking and incoherence.

In terms of negative symptoms, all of the children showed symptoms of affective flattening, inappropriate affect (laughing), and a decrease in attention and concentration. Most of the children reported symptoms of avolition, anhedonia and alogia. None of the children exhibited significant mood symptoms.


Most of the children had a variable course where there were periods of remission and then periods of psychotic episodes. A few children were chronically ill and showed a progressive deterioration. None of the children have returned to full premorbid functioning.

Psychopharmacological Treatment in Developmentally Disabled Children with Schizophrenia. Pharmacological treatment of children with schizophrenia has followed specific guidelines, as per Health Canada. That is, adequate trials of two classes of antipsychotic medication must be used prior to initiation of treatment with Clozapine. Although Clozapine is considered an excellent medication choice for treatment of schizophrenia in terms of reducing or eliminating symptoms, as well as providing maintenance stabilization of symptoms, usage is carefully monitored in Canada (Krogh, 1994). The reason for caution is the risk of patients developing agranulocytosis as a result of taking Clozapine. Agranulocytosis is an acute disease characterized by a deficit or absolute lack of granulocytic white blood cells (Thomas, 1989). Associated with this issue is that blood testing for presence of agranulocytosis must be carried out on a regular basis, which causes anxiety, discomfort and inconvenience for many individuals.

The community based mental health treatment team has until this year generally used Respiridone as the first pharmacological treatment option, due to its reputation for effectiveness and a low side effect profile, as compared to older antipsychotic medications. In this study there appeared to be a high incidence of side effects directly linked to use of Respiridone. These included Parkinsonian symptoms, rocking, repetitive rubbing, hyperactivity, tongue darting, weight gain, and dystonia. Respiridone has however, proven to be the most effective treatment thus far for addressing both positive and negative symptoms of schizophrenia.

The next line of treatment choice used for children with schizophrenia treated by the team has been a trial of one of the older traditional antipsychotic medications, such as Haloperidol. If ineffective, or presenting a high side effect profile, treatment with Clozapine was then initiated.

Recently Olanzapine has been introduced as a positive treatment choice for symptoms of schizophrenia and other psychoses. This medication is reported to offer superior efficacy in acute and maintenance treatment of both positive and negative symptoms of schizophrenia. Side effect profile appears low in trial studies. The advantage Olanzapine has over Clozapine is that there is no risk of agranulocytosis associated with its use. Another positive factor is that Olanzapine can be given once daily (Lilly, 1995). As Olanzapine is a relatively new antipsychotic medication, however, the effects of long-term use are unknown.

A recent issue in the pharmacological treatment of schizophrenia is that Pharmacare has initiated legislation that directly impacts choices of medication used. That is, clients must have a failed trial of an older, less expensive antipsychotic medication before one of the newer, more expensive neuroleptic medications, e.g., Olanzapine can be prescribed. Respiridone has recently been removed from this list and can now be used as a first line of treatment. This raises many concerns regarding long term use of medications known to have a large side effect profile. This ruling does not affect individuals who have already received one of the newer antipsychotic medications.

Home and Family Situation. All of the children with the exception of four continue to live at home. The main reason why the four children were not living at home was primarily related to the fact that their families found it difficult to manage their behavior. All of the children responded well to consistent structure and routine. In families where there was more disorganization and less structure, inevitably, these children experienced more difficulties.

All of the children showed a decrease in their activities of daily living and while some have made good gains, none have returned to premorbid functioning. A few children showed very significant decreases in their personal care skills and have become very dependent on their families to care for them. For many of the families additional support was recommended and in most cases provided: respite and child care worker for the child.

For many of the families there remained many questions and concerns after their child was diagnosed. Many of them required ongoing support from our team with education about the illness as well as medication. Many adolescents with developmental disabilities showed an increasing awareness of their differentness and their struggles with socialization. For the children in our study, their awareness seemed more acute with the onset of schizophrenia. Many of the children had questions about typical concerns (e.g., being teased, being different) but their concerns also related to their schizophrenia, (e.g., “Why do I hear voices?, Am I bad?, Have I done something wrong? Why can’t I do this anymore?”). Even for one child who had schizophrenia, disorganized type, during periods of lucidity he asked questions regarding his illness and why he had trouble thinking? For most of the children their questions and concerns were addressed through supportive psychotherapy which focused on talking about developmental disability as well as schizophrenia.

School Situation. All of the children were able to return to school after their first onset and their success in terms of integrating back into the school system was variable. All of the students required teacher assistants and substantially revised individual education plans. Many of the schools were used to having children with developmental disabilities. However the impact of a second diagnosis sometimes created confusion for schools where they did not know how to cope with the dual diagnosis. There were many schools who were apprehensive in having the children return to school and the main reason for this was an ignorance surrounding schizophrenia. This fear quickly subsided with good psychoeducational services provided that dispelled many of the myths of schizophrenia such as, aggression is a common symptom, image of Dr. Jeckyll and Mr. Hyde, and that the children would have frequent hallucinations. In fact several teachers remarked how well the children had adjusted back to school. The education also assisted the teachers in being aware of overstimulating the children and their need to be at times flexible in expectations.

There were also problems with attention and concentration. Some children had difficulty sustaining energy to last a full day at school and gradual integration was implemented. Part of the sedation was related to side effects from the medication. Some of the more higher functioning children were not able to return to their regular classes because it was felt that they could not participate fully in such a setting. Consequently, a life skills class was recommended. This decision was beneficial as it allowed the child to attend school where there were less demands and also it enabled the child to be one of the more able students in the class, thereby enhancing self-esteem.


The preliminary findings from this study suggest that the phenomenonology, course and diagnostic outcome of Early Onset Schizophrenia in the developmentally disabled are similar to the Early Onset forms in the general population. Careful developmental and clinical histories, observations of the individual and follow-up assessments were crucial in the diagnostic process.

Outcome studies reviewing early onset schizophrenia in the general population, although scant and somewhat contradictory suggest that the prognosis is at least as bad as in adult schizophrenia and may be marginally worse. Furthermore premorbid adjustment and IQ have been found to be the best predictors of outcome. What is the effect of early onset and developmental disability on prognosis? What is the relationship between rate of recovery and premorbid adjustment in children with developmental disabilities and early onset schizophrenia? These are some of the questions this study will be addressing in the future.

While early onset schizophrenia appears to be on a continuum with adult schizophrenia, some researchers have proposed that it represents a more severe neurobiological presentation (Bender, 1942, Fish, 1977). There is evidence to suggest abnormal neurological development in infants who are later diagnosed as schizophrenic. Findings of brain abnormality have been interpreted as consistent with schizophrenia being a neurodevelopmental disorder. Evidence of brain abnormalities from neuroimaging studies includes suggestions of increased ventricular size and a widening of the cortical sulci in CT Studies. CT scan abnormalities have been noted in young patients at the time of their initial onset and seem to be nonprogressive compared to adult onset schizophrenia patients where abnormalities are progressive. A future question to be examined in this study is : What type of brain abnormality is found in children with developmental disabilities and early onset schizophrenia?


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