Identifying symptoms of psychiatric disorders in people with autism and intellectual disability: an empirical conceptual analysis.
Keywords: autism, depression, psychosis, intellectual disability, OCD, anxiety, psychiatric diagnosis
Autism is a pervasive developmental disorder characterized by social and communication problems and a restricted and repetitive repertoire of interests and activities (ICD-10, (35) DSM-IV (2)). The prevalence of intellectual disability in individuals with classical autism is about 80 percent. (7,8) In recent years, comorbidity and overlap with other disorders have become a major focus for research on autism, including the presence of psychiatric disorders. (5,9,10,13,17,19,23,28,32) There is no reason to believe that autism is a protective factor against developing psychiatric illness, as evidenced by several case studies describing psychiatric symptoms in individuals with autism not related to autism. (4,5,8,13,17,18,23,28,31,34) While psychiatric symptoms and behavior problems in individuals with autism have tended to be diagnostically overshadowed and wrongly attributed to autism, (17) autism is now assumed to represent an increased vulnerability for mental health disorders. (5,8,17)
The identification of psychiatric disorders in individuals with autism and intellectual disability is, however, complex and challenging, especially due to the difficulties related to distinguishing psychiatric symptoms from the core symptoms of autism. (5,8,17,19,28,34) The considerable overlap between autism and psychiatric disorders, both theoretically and clinically, may explain both why psychiatric disorders in individuals with autism and intellectual disability are often not identified and why a complex autistic condition may be diagnosed as a psychiatric disorder. (5,8,17,19,28,34) Similar symptoms may be indicators of both autism and a psychiatric disorder. There is, for example, considerable overlap between autism and obsessive-compulsive disorder (OCD) and psychosis, especially schizophrenia. The ritualistic and repetitive behaviors that are defined as one of the core characteristics of autism may also be symptoms of OCD. Lack of social interaction may be interpreted as both a feature of autism and a symptom of schizophrenia. The impaired language and communicative skills and the reduced capacity for introspection that characterize individuals with both autism and intellectual disability, also represent challenges for the identification process.
Checklists are frequently used to identify psychiatric disorders in individuals with intellectual disability, but the two most comprehensive instruments for identifying psychopathology in this group (The Diagnostic Assessment for the Severely Handicapped-II, (DASH-II), (22) and the Psychiatric Assessment Schedule for Adults with a Developmental Disability, (PAS-ADD) (24) are problematic to use with individuals with autism because autism is one of the subscales, and their validity and reliability in identifying psychiatric disorders in individuals with autism have not been demonstrated. (18) These difficulties make it likely 18 that psychiatric disorders often remain undetected in individuals with autism and intellectual disability.
Prevalence estimates of psychiatric disorders in individuals with autism vary widely. (17) For example, a review of six studies of individuals with autism and Asperger syndrome reported prevalence of psychiatric disorders ranging from nine to 89 percent. (13) Explanations of the wide 13 variation have been related to the disorders that were targeted, the characteristics of the populations studied, and the assessment methods and diagnostic criteria that were employed. (4,13,17) The variability in findings may also reflect the conceptual confounding; several authors have pointed to the need for criteria for diagnosing psychiatric disorders in individuals with autism. (8,14,17,23,32) To our knowledge, there is no research that has systematically explored the conceptual boundaries between autism and psychiatric disorders, and the validity of the concepts of different psychiatric disorders as they are defined in diagnostic manuals when applied to individuals with autism and intellectual disability. Differentiating conceptually between these disorders is a prerequisite for diagnosing psychiatric disorders in this group.
The present study applies a panel study design to investigate which symptoms clinicians use to discriminate between autism and four major psychiatric disorders--psychosis, depression, anxiety disorder and OCD. The study explores which symptoms experienced clinicians regard as indicators of psychiatric disorders and not representing autism and which symptoms they regard as indicators representing autism, and whether the phenomenological core of the concepts representing the different psychiatric disorders in the symptoms not representing autism is maintained.
The study is based on the assumption that psychiatric disorders are conceptually similar in individuals with autism and intellectual disability and in the general population, cf. (17,25) This assumption implies both that individuals with autism and intellectual disability may suffer from the same psychiatric disorders as people without autism and that these disorders have the same core characteristics in both groups, cf. (25) The present analysis is thus based on the concepts of the four psychiatric disorders as they are defined in diagnostic manuals (i.e., ICD-10 and DSM-IV).
Selection of Indicators
Symptom clusters or domains representing the core symptomatology for each of the four psychiatric disorders and for autism were operationalized for the selection of indicators representing the concepts as they are defined in diagnostic manuals (i.e., ICD-10, DSM-IV). Items describing characteristic behaviors or symptoms for each domain were selected in accordance with the following principles:
1. All the domains represented in each of the four psychiatric disorders and autism as they are defined in ICD-10 and DSM-IV should be included (the principle of comprehensiveness).
2. The items should contain observable behavior, but items describing unobservable behavior should be included when the symptom clusters are impossible to be represented only by observable behavior (the principle of behavioral equivalents).
3. All the different behavior descriptions within each symptom cluster should be included (the principle of over-inclusiveness).
Based on the descriptions in ICD-10 and DSM-IV psychosis was operationalized with symptoms within the following three domains: positive symptoms, negative symptoms and disorganization. The domains mood, cognition, psychomotor and somatic represented depression. Anxiety disorder was operationalized by symptoms within the domains physiological arousal, avoidance and cognition; and OCD with symptoms within the domains rituals, repetitive behavior and obsessions. All the symptom domains of the five disorders were represented by one or more items.
Symptom descriptions were obtained from several psychiatric diagnostic checklists including behavior descriptions that are accepted as valid indicators of psychiatric disorders (i.e., Psychiatric Assessment Schedule for Adults with a Developmental Disability (PAS-ADD), (24) The Psychopathology Instrument for Mentally Retarded Adults (PIMRA), (21) The Diagnostic Assessment of the Severely Handicapped, (DASH II), (22) Reiss Screen for Maladaptive Behavior, (29) Yale Brown Obsessive-Compulsive Scale (Y-BOCS), (11) Global Assessment of Functioning scale (GAF), (6,26) Positive and Negative Syndrome Scale (PANSS), (16) The Hospital Anxiety and Depression Scale (HAD), (12,36) Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS), (15) Aberrant Behavior Checklist (ABC). (1) When the same or very similar behavior descriptions were found as items in more checklists, only one of these items were included. A total of 118 items were selected from the PAS-ADD, (24) Y-BOCS, (11) and PANSS. (16) Sixty-six additional items were included based on descriptions in the ICD-10, DSM-IV and various case studies. The Autism Diagnostic Interview-Revised (ADI-R), (20) is considered the best standardized diagnostic instrument for autism. (33) Seventy items from this instrument describing typical autistic behavior were selected to represent the concept of autism.
The total item pool for investigation encompassed 254 items: Among indicators of psychosis 43 items were selected, 70 items were selected among indicators of OCD, 39 items among indicators of anxiety disorder, 32 items among indicators of depression, and 70 items among indicators of autism.
The Evaluation Procedure
A panel of nine interdisciplinary and experienced clinicians was recruited from the specialist health services, two departments at Ulleval University Hospital in Oslo and the National Autism Unit of Norway. The clinicians independently rated the 254 randomly ordered items on a six-point scale (0= the content of the item does not represent the disorder, 5= the content of the item represents the disorder very well). Clinicians gave all items a score for every disorder according to how well the item represented each of the four psychiatric disorders and autism.
Data were analyzed using the Statistical Package for Social Science (Version 13.0).
Results and Analysis
The average score of the ratings of the nine clinicians' evaluations was calculated for each item for the five disorders. The items were categorized according to how well they were evaluated to represent each of the disorders. Five item categories were established:
1. Autism-specific items (i.e., items with an average score for autism of 3.0 or higher and below 2.5 for all the other disorders).
2. Disorder-specific items not representing autism (i.e., items with an average score for one of the psychiatric disorders of 3.0 or higher and below 2.5 for autism and the other psychiatric disorders).
3. Overlapping items (i.e., items with an average score of 2.5 or higher for autism and 3.0 or higher for one of the psychiatric disorders).
4. Non-specific items (i.e., items with an average score of 2.5 or higher for both autism and at least two other disorders, or for three of the psychiatric disorders).
5. Items with large inter-rater variability (i.e., items with a standard deviation above 1.5). A standard deviation below this value was considered to reflect acceptable rater agreement while a standard deviation above this value reflected disagreement among the clinicians' evaluations.
The results of the categorization of the items are presented in Table 1. All the 70 items originally selected as indicators of autism obtained a score of 3.00 or higher for autism and below 2.5 for all the other disorders and were thus categorized as autism-specific. Among the 184 items selected as indicators of the four psychiatric disorders, sixty-one items obtained a score of 3.0 or higher for one of the psychiatric disorders and below 2.5 for autism and the other psychiatric disorders and were thus disorder-specific items and not representative of autism. In this category there were 16 items (37%) representing psychosis, 17 items (53.1%) representing depression, 17 items (43.6%) representing anxiety disorder, and 11 items (15.7%) representing OCD. The items rated as disorder-specific represent the same symptom domains as those operationalized for item selection. The disorder-specific items are listed in the Appendix A.
The items originally selected to represent OCD overlapped most often with autism. Forty-four of the 70 OCD items (62.9%) were given an average score of 2.5 or more on autism, indicating a significant overlap in symptomatology between autism and OCD. Seventeen of the 43 items selected to represent psychosis (39.5%) received a score of 2.5 or higher for autism and were categorized as overlapping as well. Eight of the 39 anxiety disorder items (20.5%) and three of the 32 depression items (9.4%) were given a score of 2.5 or higher for autism. Among the 18 items rated as non-specific, four were originally selected as indicators of psychosis, seven as indicators of depression, five as indicators of anxiety disorder, and two as indicators of OCD. A standard deviation above 1.5 was defined to reflect disagreement among the clinicians' evaluations. Thirty-two items (13%) had a standard deviation above 1.5 and 222 items (87%) had a standard deviation below 1.5.
Table 2 shows the average scores for the 61 disorder-specific items, for all the disorders, which indicate to what extent the items were seen as representative of the specific disorder as well as the other disorders. The 11 items selected as indicators of OCD had the highest average score of 4.67 for OCD and between 0.67 and 1.59 for the other disorders. The psychosis items had an average score of 4.19 for psychosis and between 1.15 and 2.10 for the other disorders. The depression items had an average score of 3.84 for depression and between 0.28 and 1.30 for the other disorders. The anxiety disorder items obtained an average score of 3.61 for anxiety disorder, and between 1.01 and 1.31 for the other disorders. The average scores of the items selected as indicators of a specific disorder were higher than 3.60 and the scores for the other conditions were below 2.10.
The inter-rater agreement for the disorder-specific items was calculated by correlating the score of each individual clinician with the rating of the eight other raters (Table 3). A score of 1.00 would indicate an absolute agreement among raters. The correlations for the OCD items were between 0.96 and 1.00, and for the psychosis items between 0.78 and 0.83. The items representing depression had somewhat lower correlations, between 0.67 and 0.72, while the correlations for the items representing anxiety disorder were between 0.58 and 0.66.
The results of the present study demonstrate that it is possible conceptually to differentiate between symptom descriptions of autism and of the four psychiatric disorders in individuals with intellectual disability, as well as between the four psychiatric disorders. The evaluation identified a set of symptoms which were rated as specific to a psychiatric disorder and not characteristic of autism as it appears in individuals with intellectual disability. Because the same symptom domains used in item selection are represented by the disorder-specific items not representing autism, the phenomenological core of the concepts representing the different psychiatric disorders seems to be maintained. The disorder-specific items may therefore be used as indicators of psychiatric disorders in individuals with autism and intellectual disability.
Among the 184 items selected to represent core symptomatology of the four psychiatric disorders in individuals with intellectual disability, only 61 items (33%) were rated as disorder-specific not representing autism. The fact that a large proportion of these items (72 out of 184 items, 39%) were rated as representing autism, suggests that many of the items often used in identifying psychiatric disorders in individuals with intellectual disability do not work in identifying psychiatric disorders in individuals who also have autism. The results also demonstrate the comprehensive conceptual overlap between autism and psychiatric disorders and the difficulty of differentiating between them.
The picture that emerges in the five different categories further reflects the complexities of the conceptual overlap between autism and psychiatric disorders. Seventy-two items were regarded as characteristic of both autism and one of the psychiatric disorders. These items represent the conceptual overlap between autism and the psychiatric disorders and may be considered unsuitable for identifying psychiatric disorders in individuals with autism. The eighteen non-specific items were regarded as representing at least three disorders and were not specific representing the disorder they originally were selected to measure. They may consequently be considered as general indicators of impaired functioning or mental health problems. The items with large inter-rater variability are assumed to represent differences in the clinicians' considerations of the various symptoms. This assumption is supported by the fact that seven of these items had descriptions of two or more behaviors. However, with only 32 items in this category (13%), the nine expert clinicians demonstrated acceptable agreement on the majority of the items (222 items, 87%).
Nearly 40% of the items selected as indicators of psychosis were rated as overlapping items, supporting earlier reports of confusion between clinical features of autism and negative symptoms of schizophrenia. Odd and unusual features in people with autism and idiosyncratic preoccupations has been mistaken for delusions or other positive signs of schizophrenia, and language problems in individuals with autism has been confused with thought disorder. (5,17)
In the present study, depression was the disorder with the lowest proportion of items rated as overlapping with autism (9.4%). This result probably reflects the quite different situation of identifying depression symptoms in a clinical setting compared to evaluating symptom descriptions theoretically. Studies of clinical populations have concluded that depression, as in the general population, is the most common psychiatric disorder in persons with autism. However, studies have also demonstrated that most professionals tend to overlook symptoms of this diagnosis in individuals with autism, and in 10 particular mood changes have been difficult to observe. (27)
Anxiety disorder had the highest proportion of items with large variability (23.1%), and the average score and inter-rater agreement scores of the items rated as specific to anxiety disorder were rather low. The findings illustrate the difficulty of differentiating between anxiety disorder and autism conceptually. Symptoms of anxiety disorder are often described in individuals with autism. (8,13,17,31) According to the DSM-IV, however, the diagnosis of anxiety disorder should not be made if the symptoms occur in the context of autism, implying that anxiety symptoms are part of autism. (17) However, clinical practice of identifying anxiety disorder in individuals with autism has recently changed, justified by the demands of efficient treatments. (10) The special challenges of differentiating between autism and anxiety disorder clinically are illustrated by the fact that similar behavior may be interpreted differently depending on the person's premorbid autistic behavior and idiosyncratic expressions. Repetitive questioning, for example, may be interpreted as a sign of anxiety disorder, verbal rituals or communication problems. (9)
The largest proportion of overlapping items consisted of items selected as indicators of OCD (62.9% of the OCD items). This finding demonstrates the previously noted conceptual overlap between autism and OCD. Moreover, it also implies a need for exercising caution in diagnosing OCD in individuals with autism using diagnostic instruments developed for the general population. It also supports the recent call for modifying existing checklists used for identifying OCD in individuals with autism. (30)
The finding that all the items selected as indicators of autism were rated as characteristic to autism legitimates the clinicians' evaluation and supports previous reports of autism as a well validated diagnosis. (33) Moreover, the result 33 indicates that the core characteristics of autism are defined without overlaps with psychiatric disorders, unlike the items in checklists of psychiatric disorders in individuals with intellectual disability which tend to overlap with autism.
The disorder-specific items which were identified in the present study were generally rated as good indicators of the disorder they represented. All the average scores of the specific-disorder items were higher than 3.60 for the disorder they represented. Especially, the OCD items (average score of 4.67) and the psychosis items (average score of 4.14) were evaluated as very good indicators, while the depression items (average score of 3.84) and the anxiety items (average score of 3.61) were evaluated somewhat lower. Moreover, the disorder-specific items were generally found not to represent any of the other disorders and to represent different psychiatric disorders. The average scores of the specific-disorder items were generally below 2.10 for the other conditions. The psychosis items got the highest score related to another disorder (depression 2.10), suggesting that the psychosis items to some extent also may represent depression. All the other average scores related to other psychiatric disorders were below 1.40. Generally, the inter-rater agreement on the disorder-specific items also demonstrate acceptable agreement for the disorder that the item represented, and hence on the relevance for each disorder. The results demonstrate that the items selected as indicators for OCD and psychosis were rated the most similar (correlation between 0.96 and 1.00, and between 0.78 and 0.83), while the ratings for the depression items and anxiety disorder items varied somewhat more (between 0.67 and 0.72, and between 0.58 and 0.66).
The high level of agreement in the clinicians' rating of the psychosis items are probably related to the positive symptoms, hallucinations and delusions which particularly characterize and define psychosis. (8) Supposing that is the case, the 8 results indicate that the most valid psychosis items may in fact be the least observable because these symptoms are extremely difficult to assess in persons with communication problems. Impaired global functioning, severe adjustment problems and challenging behavior have traditionally indicated psychosis within this group. It has been argued that these indicators could give many false positive diagnoses, because they might indicate a broad range of other problems in persons who cannot report their own symptoms. (8) However, the negative and disorganization items that were rated as specific to psychosis in this study, have been found to be valid observable indicators of psychosis in individuals with autism and intellectual disability. (3)
In the present study, the specific depression items obtained both a moderate average score on depression (3.84) and moderate inter-rater correlations (correlations between 0.67 and 0.72). In addition, the average score of the specific psychosis items related to depression (2.10) indicate that the psychosis items to some extent are related to depression. The item "less initiative" may particularly be associated to both psychosis and depression. However, the low average scores related to the other disorders for the depression items (between 0.28 and 1.30) indicate that the depression items are not representing any of the other disorders and distinguish well. Moreover, all the four symptom domains used in the item selection are represented by the specific depression items, indicating that the theoretical validity of depression seems well maintained. The results are in accordance with other reports suggesting depression may be identified using existing diagnostic criteria. Regulation symptoms, such as changes in sleep or eating, are among the most easily observed symptoms. (17)
The specific anxiety disorder items obtained both an average score on anxiety disorder (3.61) and inter-rater agreement correlations that were relatively low. The specific anxiety disorder items encompass twelve items representing the symptom domain "physiological arousal" and four items representing "avoidance." Only one item, "fear of losing control," is representing the symptom domain "cognition." It may be difficult to differentiate between the experience of anxiety and the anxiety reaction, as well as between reactions related to a known object and reactions related to an unknown object (i.e., between a phobia and a generalized anxiety disorder) in clinical settings with individuals with autism and intellectual disability. Expanding the number of anxiety disorder items that represent the domain "cognition" may have led to higher scores and improved the conceptual validity, but not the clinical applicability. Such items would be extremely difficult to assess in persons with communication problems. However, the low average scores related to the other disorders for the anxiety disorder items (between 1.01 and 1.31) indicate that the anxiety items are not representing any of the other disorders. The findings in the present study thus indicate that anxiety disorder may be identified in individuals with autism and intellectual disability with the same or similar symptoms as in normally developing individuals.
The considerable difference between the average score of the specific OCD items for autism (1.59) and the score for OCD (4.67) demonstrate the possibility of differentiating between the two disorders conceptually. Rituals and repetitive behaviors are part of the core symptom clusters of autism and thus the differentiation between OCD and autism has been considered especially complicated. Clinically the difference between the two conditions has been described as the striking difference between not bothersome and even pleasurably repetitive behavior related to autism, contrasted to OCD, where repetitive behavior occur to reduce anxiety and when prevented from continuing the repetitions, severe distress is displayed. (30) The compulsions associated with autism are not egosyntonic, that is, they do not seem to occur against the person's will, (8) while OCD is characterized by a compulsion-driven quality. (17)
The disorder-specific items identified in this study may reveal the diagnostic clues used by experienced clinicians in identifying psychiatric disorders in persons with autism, especially in persons in this group who have language and communication problems. The growing volume of published research on the presence of psychiatric disorders in persons with autism indicate that experienced clinicians have, in spite of the lack of specific diagnostic criteria, identified psychiatric disorders in this population. (5,8,10,13,17,19,23,28,32) The diagnostics has been partly based on identifying qualitative changes in long-standing symptomatology in the individual's premorbid features of autism, on using conventional diagnostic criteria related to specific disorders, and on the interpretation of idiosyncratic or atypical symptoms. (8,17)
The focus of the present study has been on four major psychiatric disorders and does not include the full range of comorbid psychopathology reported in individuals with autism and intellectual disability, cf. (5,8,10,17,23) The study was based on the assumption that psychiatric disorders are conceptually similar in individuals with autism and intellectual disability
as in the general population and the concepts of the disorders as they are defined in diagnostic classification systems (i.e., ICD-10 and DSM-IV). However, it is possible that psychiatric disorders in individuals with autism and intellectual disability may manifest themselves in different ways than in other groups. (5,17)
It is important to note that the aim of the present study has been to investigate which symptoms clinicians use for discriminating between autism and psychiatric disorders. This is not the same as differentiating between individuals who have different disorders. There is likewise no reason to doubt that all the indicators of psychiatric disorders which were evaluated in this study are adequate for assessing psychiatric disorders. In accordance with additional disorders and co-morbidity, however, it is important to identify indicators that distinguish between the disorders. There seems to be a general agreement that in order to make accurate diagnostic assessments and provide appropriate services for individuals with autism with additional problems, it is necessary to distinguish between symptoms that are representing the autistic condition and symptoms that are representing other psychiatric conditions. (8,17,32)
The contribution of the present study is the demonstration of the possibility of conceptually differentiating between the psychiatric disorders and autism. The set of symptoms that were identified as specific to a psychiatric disorder and not characteristic of autism may be used as indicators of psychiatric disorders in individuals with autism and intellectual disability. The present study may, therefore, represent a step toward more accurate and reliable diagnoses as well as to a better delineation of the autistic disorder in this group. To our knowledge, a similar study has not been published before, and future replications will be desirable.
ACKNOWLEDGMENT: The project is funded by, and part of, a project established by The National Autism Unit at the Rikshospitalet University Hospital in Norway and the former National Autism Network of Norway with the objective of ensuring necessary services for adults with autism, intellectual disability and psychiatric disorders. The project represents collaboration between the National Autism Unit and two departments at Ulleval University Hospital in Oslo: the Department for Habilitation of Adults and the Psychiatric Department for Adults with Intellectual Disability. The expert clinicians were recruited from the National Autism Unit and the two departments at Ulleval University Hospital. We appreciate their participation.
APPENDIX A: DISORDER-SPECIFIC ITEMS, N=61 NOTE: THE TABLES DO NOT ENCOMPASS THE FULL ITEM FORMULATION, ONLY ITEM LABEL.
Psychosis-specific items N=16
Derail within conversation or task
Rapid mood fluctuations
Gross disorientation in known areas
Gross disorientation within social interaction
High motor activity
High communicative activity
Depression-specific items N=17
Tired during the day
Difficulties falling to sleep
Wakes up early
Needs much help to get started in the morning
Reduced motor skills
Reduced self- image
Reduced social interaction
Extreme slow movements
Lost interest in previous favorites
Unable to follow known instructions
Seems to be sad and dejected
Anxiety disorder-specific items N=17
Increased fear and avoidance
Complains about numbness
Fear in special situations
Seems to be nervous
Freezes in situations
Seems to be tense
Change in muscle tone
Fear of losing control
Diarrhea or vomit
OCD-specific items N=11
Obsessed by right performance
Distress when rituals are prevented
Peculiar behavior pattern
Obsessed by knowing
Obsessed by order and symmetry
Overdoes washing or teeth brushing
A fixed numbers of repetitions
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SISSEL BERGE HELVERSCHOU,  TRINE LISE BAKKEN, RN, MHSC  & HARALD MARTINSEN 
 The National Autism Unit, Rikshospitalet University Hospital, Oslo, Norway
 Division of Psychiatry, Ulleval University Hospital, Oslo, Norway
 Department of Special Needs Education, University of Oslo, Norway
CORRESPONDENCE: Sissel Berge Helverschou, The National Autism Unit, Rikshospitalet University Hospital, Forskningsveien 1, 0373 Oslo, Norway; email: s.b.helverschou@ rikshospitalet.no.
TABLE 1. DISORDERS, SYMPTOM DOMAINS AND ITEM CATEGORIZATION IN THE CONCEPTUAL ANALYSIS DISORDERS SYMPTOM NUMBER DISORDER- NON- DOMAINS OF SPECIFIC SPECIFIC ITEMS ITEMS ITEMS Psychosis Positive symptoms 14 5 0 Negative symptoms 10 1 2 Disorganization 19 10 2 Total 43 16 4 (37.2%) (9.3%) Depression Mood 9 4 4 Cognition 2 1 0 Psychomotor 9 6 2 Somatic 12 6 1 Total 32 17 7 (53.1%) (21.9%) Anxiety Physiological Disorder arousal 29 12 4 Avoidance 6 4 0 Cognition 4 1 1 Total 39 17 5 (43.6%) 12.8%) OCD Rituals 19 6 2 Repetitive behavior 18 2 0 Obsessions 33 3 0 Total 70 11 2 (15.7%) (2.8%) Autism Communicative problems 21 0 0 Social problems 29 0 0 Repetitive behavior 20 0 0 Total 70 0 0 Total 254 61 18 (100%) (24%) (7%) DISORDERS SYMPTOM OVER- LARGE AUTISM DOMAINS LAPPING VARIABILITY SPECIFIC ITEMS ITEMS ITEMS Psychosis Positive symptoms 9 0 0 Negative symptoms 6 1 0 Disorganization 2 5 0 Total 17 6 0 (39.5%) (14.0%) Depression Mood 1 0 0 Cognition 1 0 0 Psychomotor 0 1 0 Somatic 1 4 0 Total 3 5 0 (9.4%) (15.6%) Anxiety Physiological Disorder arousal 6 7 0 Avoidance 1 1 0 Cognition 1 1 0 Total 8 9 0 (20.5%) (23.1%) OCD Rituals 9 2 0 Repetitive behavior 13 3 0 Obsessions 22 8 0 Total 44 13 0 (62.9%) (18.6%) Autism Communicative problems 0 0 21 Social problems 0 0 29 Repetitive behavior 0 0 20 Total 0 0 70 (100%) Total 72 33 70 (28%) (13%) (28%) Disorder-specific items (not representing autism) = obtained an average score $ 3.0 for a specific psychiatric disorders and < 2.5 for autism and the other psychiatric disorders. Non-specific items = obtained an average score of $2.5 for three or more disorders. Overlapping items = obtained an average score of $2.5 for autism and of $3.00 for one of the psychiatric disorders. Large variability items = obtained a standard deviation above 1.5 (SD $1.5). Autism-specific items = obtained an average score of $3.00 for autism and < 2.5 for all the other disorders. Percent is calculated among the items representing each disorder. TABLE 2. THE AVERAGE SCORES FOR THE DISORDER-SPECIFIC ITEMS AVERAGE SCORES ITEMS Psychosis Depression Anxiety OCD Autism Psychosis 4.19 2.10 1.40 1.15 1.48 Depression 1.26 3.84 1.30 0.28 1.06 Anxiety disorder 1.01 1.31 3.61 1.11 1.01 OCD 0.67 0.70 1.19 4.67 1.59 N = 61 items. Scale: 0 - 5, 0 = the content of the item does not represent the disorder 5 = the content of the item represents the disorder very well TABLE 3. INTER-RATER AGREEMENT AMONG THE INDIVIDUAL RATERS CLINICIAN PSYCHOSIS DEPRESSION ANXIETY OCD 1 0.78 0.67 0.60 0.96 2 0.82 0.69 0.64 1.00 3 0.79 0.67 0.60 0.96 4 0.79 0.68 0.61 0.96 5 0.82 0.65 0.58 0.98 6 0.79 0.70 0.66 0.96 7 0.83 0.72 0.63 0.96 8 0.80 0.67 0.64 0.96 9 0.79 0.69 0.64 0.98 The score of each individual clinician on each psychiatric disorder is correlated with the rating of the eight other raters.
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|Author:||Helverschou, Sissel Berge; Bakken, Trine Lise; Martinsen, Harald|
|Publication:||Mental Health Aspects of Developmental Disabilities|
|Date:||Oct 1, 2008|
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