A COMPARISION OF THE PERFORMANCE OF CHILDREN WITH AND WITHOUT LEARNING DISABILITY ON THE SENSORY PROFILE TOOL

Transcription

1 The Indian Journal of Occupational Therapy : Vol. XXXVI : No. 3 (December '04-March 05) A COMPARISION OF THE PERFORMANCE OF CHILDREN WITH AND WITHOUT LEARNING DISABILITY ON THE SENSORY PROFILE TOOL Sanjeev. M. Padankatti, MOT Christian Medical College & Hospital, Vellore Abstract : The purpose of the study was to determine whether the 99 item Sensory Profile Tool discriminates between children with and without Learning Disability and which items on the profile best discriminates between these groups. Parents of 35 children with Learning Disability and 70 children without Learning Disability aged 5-12 years of both genders completed the Sensory Profile. Parents used a 5-point Likert scale to report the percentage of time their children engaged in each behavior. A descriptive analysis identified the distribution of responses on each item. An analysis of variance [ANOVA] identified trends in performance, and age and gender differences. Sixty Four [65%] of the 99 items were found to be uncommon behaviors for the sample of children without Learning Disability. Children with Learning Disability performed differently on all categories on the Sensory Profile. 7 Items were found to be common behaviors for this sample of children. Age and gender differences were significant on several individual items for both samples of children. The Sensory Profile Tool can provide information about the sensory processing patterns of children with and without Learning Disability to assist Occupational Therapists in assessing and program planning for these children. INTRODUCTION The experience of being human is imbedded in the sensory events of everyday life. Sensation is so intimate and personal that we use it to define our individuality. Sensory integration is considered to be the foundation for appropriate occupational behavior including self-care, self-management, play and academic skills. Fisher and Murray (1991). DeGangi (1991) theorized that problems in sensory processing seen in children with learning disabilities could lead to difficulties in the acquisition of perceptual skills, language development, sensory integration, and emotional expression. Ayres (1972) reported that occupational therapy using sensory integrative approaches when coupled with special education was a promising method for improving academic scores of children with learning disability. AIMS AND OBJECTIVES The purpose of this study was to determine whether the Sensory Profile Dunn (1994) discriminates children with Correspondence : Dr. Sanjeev M. Padankatti Lecturer, Dept. of Occupational Therapy, Christian Medical College & Hospital, Vellore (T.N.) Tel. : sanjeevpadankatti@yahoo.com The recipient of AIOTA Trophy for the Best Paper on Mental Health; presented in 41st Annual Nat. Conf. of AIOTA in the year 2004 at New Delhi. learning disability from children who are typically developing and which items on the sensory profile best discriminates between these groups. An additional purpose was to determine which of the statement on the sensory profile represent commonly occurring behaviors of children with learning disability, and to identify age, gender and functional differences in performance on the Sensory Profile. METHODOLOGY Study Population A convenience sample of 105 children was taken up for the study. 35 children with an established diagnosis of Learning disability,and 70 children who were Typically developing. Children were considered Typical when not taking medication (inattention & Seizures) and not receiving special services at school. Children with Learning Disability were referred or receiving services at the Occupational Therapy Department and a diagnosis was established as part of the clinical assessment Measures and instruments 1. Sensory Profile Tool (Dunn 1994) : The sensory profile was used to assess sensory processing. It consists of 99 items divided into six sensory categories, (Auditory = 9 items, Visual = 12 items, Taste / Smell = 6 items, Movement =18 items, Body position =10 items, and Touch =21 items) and two behavioral categories, (Emotional / Social =20 items and Activity level = 3 items). 63

2 Using a 5 point Likert scale, the parents responded to each behavioral statement as follows: 1=always: when presented with the opportunity, the child responds in the manner described every time, or 100% and 5 = never : when presented with the opportunity, the child never responds in this fashion or 0%. 2. Children s Global Assessment Scale (CGAS) (Shaffer 1983) : This is a clinician rated instrument designed to assess the global functioning of the child, by reflecting the lowest level of functioning over a specified time period. The scores range from-1 reflecting the lowest level of functioning to 100 for the healthiest level of functioning. A score of above 70 indicates a normal level of functioning Procedure All parents signed the informed consent forms to indicate their agreement to participate in the study. The investigator completed the CGAS for each child with learning disability through observation of the child and assistance from the parent as needed. The investigator was always present as one or both of the parents completed the sensory profile form. DATA ANALYSIS To determine the representativeness of the two samples, a descriptive analysis of the total data set was done to identify the patterns of response for each item on the Sensory Profile. To make age, gender and functional level comparisons an analysis of variance (ANOVA) on each items on the Sensory Profile was conducted because single item analysis enabled capture of all available data in each comparison. Data of sample 2 (children with learning disability) was divided by the conventional principle of median split (Ragin, 1994) to determine the functional level of children. The median score on the CGAS was 50, which was used to dichotomize the children into low functioning (below 50) and high functioning (50 and above) level. The data was analyzed with Microsoft Excel (Microsoft Corporation 2000) and (Statistical Package for Social Sciences 9.0 for Windows (SPSS1998). RESULTS & DISCUSSION Characteristics Of Children With And Without Learning Disability The sample for typically developing children consisted of 28 girls and 42 boys (n=70) between the ages of 5-12 years. The sample for children with learning disability consisted of 10 girls and 25 boys (n=35) between the ages of 5-12 years. The diagnosis of learning disability was established for all children as a part of the clinical assessment. Functional Levels of Children with Learning Disability The Children s Global Assessment Scale was used to determine the functional status of the children. All typically developing children scored above 75 (scores ranging between ). In the category of younger children with learning disability (5-8 years) 6 children were low functioning and 11 children were high functioning. In the older group of children (9-12) 6 children were low functioning and 12 high functioning. Frequency of Occurrence of Behaviors in Typical Children Table-1 Percentage of Typical Children who Seldom or Never Displayed the Behaviors on the Sensory Profile AUDITORY % 1. Response negatively to unexpected or loud noise Is distracted or has trouble functioning if there is a lot of noise around Enjoys strange noises / seeks to make noise for noise sake Appears not to hear what you say Holds hands over ears Can t work with back ground noise? Doesn t respond when name is called Talks self through task Seems oblivious within an active environment VISUAL 1. Expresses discomfort or avoids bright lights Happy to be in the dark Looks carefully or intensely at objects / people Has difficulty putting puzzles together Hesitates going up or down curbs or steps Gets lost easily Has a hard time finding objects in competing backgrounds Has trouble staying between the lines when coloring or when writing Covers eyes or squints in bright lights Watches every one when they move around the room Avoids eye contact Doesn t notice when people come into the room TASTE/ SMELL 1. Deliberately smells objects Shows strong preference for certain smells Shows preference for certain tastes Chews/ Licks non food items Craves certain foods Does not seem to smell strong odors MOVEMENT 1. Becomes anxious or distressed when feet leave ground Fears falling or heights Dislikes activities where head is upside down

3 4. Avoids climbing, jumping, bumpy or uneven ground Avoids playground equipment or moving toys Rocks unconsciously during other activities Continually seeks out all kinds of movement activities Takes excessive risks during play Dislikes riding in a car Holds head upright, even when bending over or leaning Holds on to walls or banisters Becomes disoriented after bending over sink, table Becomes overly excitable after a movement activity Turns whole body to look at you Prefers sedentary activities Poor endurance / tires easily Appears lethargic Rocks in desk / chair /on floor TOUCH 1. Avoids getting messy Expresses discomfort during grooming Prefers long-sleeved clothing when it s warm or short-sleeved clothing when it s cold Expresses discomfort at dental work or tooth brushing Is sensitive to certain fabrics Avoids going barefoot, especially in sand or grass Reacts emotionally or aggressively to touch Rigid rituals in personal hygiene Picky eater, especially regarding textures Withdraws from splashing water Has difficulty standing in line or close to other people Rubs or scratches out a spot that has been touched Gags easily with food textures, food utensils in mouth Displays unusual need for touching certain toys, surfaces or, textures Avoids wearing shoes, loves to be barefoot Mouths objects frequently. (i.e. :pencil, hands ) Decreased awareness of pain and temperature Always touching people and objects Doesn t seem to notice when some one touches arm or back Doesn t seem to notice when face or hands are messy Leaves clothes twisted on body ACTIVITY LEVEL 1. Always on the go Prefers quiet, sedentary play Difficulty paying attention BODY POSITION 1. Hangs on people, furniture, objects, even in familiar situations Seems to have weak muscles Tires easily, when standing or holding a particular body position Locks joints (e.g.: elbows, knees) for stability Walks on toes Appears to enjoy falling Moves stiffly Has a weak grasp Can t lift heavy objects Props to support self EMOTIONAL/ SOCIAL 1. Uses inefficient ways of doing things Seems to have difficulty, liking self Needs more protection for life than other children Has trouble growing up Is overly affectionate with others Is sensitive to criticism Has definite fears Seems anxious Seems accident prone Has difficulty tolerating changes in plans and expectations Is stubborn and uncooperative Has temper tantrums Has nightmares Doesn t express emotions Doesn t perceive body language or facial expressions Poor frustration tolerance Cries easily Doesn t have a sense of humor Overly serious Has difficulty making friends Applying Dunn s (1994) criterion to specify an item as an uncommon behavior for Typical children (80% or more parents reported that their child displayed the behavior seldom or never) 64 (65%) of the 99 items were uncommon behaviors for Typical children (bolded items on Table 1). These items may indeed differentiate children who have sensory processing problems from those who do not. 12 items were very common for these children (more than 50% of children performed these behaviors occasionally, frequently or always, Dunn, 1994). These common behaviors are not likely to be appropriate items for an assessment of sensory processing problems. These items may have been worded poorly or suggested a desirable trait to the parent. The remaining 35 items did not meet this criterion. These children more commonly engaged in these behaviors (see non bolded items on Table-3). 3 categories (Movement 72%, Touch 76% and Body position -90%) had a high number of items that met the uncommon behavior criterion. These are the most commonly examined sensory systems in the occupational therapy literature on sensory integration. The finding that 65% (64 of the 99) items describe behaviors that are uncommon for these typical children suggests that 65

4 these items may indeed differentiate children who have sensory processing problems from those who do not. Twelve of the behaviors on the sensory profile occur commonly in these children. These common behaviors are not likely to be appropriate items for an assessment of sensory processing problems. If a child displayed one or more of these twelve behaviors, the therapist would not know whether the behaviors were present as a result of typical development or because of a dysfunction. Three categories (Movement 72%, Touch 76% and Body position -90%) had a high number of items that met the uncommon behavior criterion. These are the most commonly examined sensory systems in the occupational therapy literature on sensory integration. This data suggests that these categories can be used with greater confidence in practice. In other words, if an occupational therapist obtained proprioception, tactile and vestibular items data from a child s parent and observed that the child demonstrated several of these behaviors, the therapist may be assured that these responses indicate that the child responds differently than children without disabilities in these sensory categories. Table-2 Percentage of Children with & without Learning Disability who Always or Frequently Displayed the Behaviors on the Sensory Profile % AUDITORY WITH WITHOUT LD LD 1. Response negatively to unexpected or loud noise Is distracted or has trouble functioning if there is a lot of noise around Enjoys strange noises / seeks to make noise for noise sake Appears not to hear what you say Holds hands over ears Can t work with back ground noise? ** Doesn t respond when name is called Talks self through task Seems oblivious within an active environment VISUAL 1. Expresses discomfort or avoids bright lights Happy to be in the dark Looks carefully or intensely at objects / people Has difficulty putting puzzles together Hesitates going up or down curbs or steps Gets lost easily Has a hard time finding objects in competing backgrounds Has trouble staying between the lines when coloring or when writing Covers eyes or squints in bright lights Watches every one when they move around the room Avoids eye contact Doesn t notice when people come into the room TASTE/ SMELL 1. Deliberately smells objects Shows strong preference for certain smells Shows preference for certain tastes Chews/ Licks non food items Craves certain foods Does not seem to smell strong odors MOVEMENT 1. Becomes anxious or distressed when feet leave ground Fears falling or heights Dislikes activities where head is upside down Avoids climbing, jumping, bumpy or uneven ground Avoids playground equipment or moving toys Rocks unconsciously during other activities Continually seeks out all kinds of movement activities. ** Takes excessive risks during play Dislikes riding in a car Holds head upright, even when bending over or leaning Holds on to walls or banisters Becomes disoriented after bending over sink, table Becomes overly excitable after a movement activity Turns whole body to look at you Prefers sedentary activities Poor endurance / tires easily Appears lethargic Rocks in desk / chair /on floor. ** TOUCH 1. Avoids getting messy Expresses discomfort during grooming Prefers long-sleeved clothing when it s warm Or short-sleeved clothing when it s cold Expresses discomfort at dental work or tooth brushing Is sensitive to certain fabrics Avoids going barefoot, especially in sand or grass Reacts emotionally or aggressively to touch Rigid rituals in personal hygiene Picky eater, especially regarding textures Withdraws from splashing water Has difficulty standing in line or close to other people Rubs or scratches out a spot that has been touched

5 13. Gags easily with food textures, food utensils in mouth Displays unusual need for touching certain toys, surfaces or, textures Avoids wearing shoes, loves to be barefoot Mouths objects frequently. (i.e. :pencil, hands ) Decreased awareness of pain and temperature Always touching people and objects Doesn t seem to notice when some one touches arm or back Doesn t seem to notice when face or hands are messy Leaves clothes twisted on body ACTIVITY LEVEL 1. Always on the go Prefers quiet, sedentary play Difficulty paying attention BODY POSITION 1. Hangs on people, furniture, objects, even in familiar situations Seems to have weak muscles Tires easily, when standing or holding a particular body position Locks joints (e.g.: elbows, knees) for stability Walks on toes Appears to enjoy falling Moves stiffly Has a weak grasp Can t lift heavy objects Props to support self. 0 0 EMOTIONAL/ SOCIAL 1. Uses inefficient ways of doing things Seems to have difficulty, liking self Needs more protection for life than other children. ** Has trouble growing up Is overly affectionate with others Is sensitive to criticism Has definite fears Seems anxious Seems accident prone Has difficulty tolerating changes in plans and expectations Is stubborn and uncooperative Has temper tantrums Has nightmares Doesn t express emotions Doesn t perceive body language or facial expressions Poor frustration tolerance. ** Cries easily Doesn t have a sense of humor Overly serious Has difficulty making friends Frequency of Occurrence of Behavior in Children with Learning Disability 7 items on the sensory profile met the criterion for a behavior to be considered common. (80% or more of the parents reported that their child displayed the behavior always or frequently) (Bolded items on Table-2). 5 items on the Sensory Profile though they did not meet the established criterion for a behavior to be considered common, was exhibited more than 50% times. (items * on Table -2). Learning disability has been frequently referred to as an invisible handicap since children with learning disability do not look handicap. It is commonly accepted that children with learning disability demonstrate less varying patterns of functional difficulties and responsiveness to sensory events than a disability like Autism. Children with learning disability are known to exhibit many of the sensory seeking behaviors seen in normal children, but with greater frequency or intensity. In addition inattention, distractibility and perceptuomotor dysfunction tend to impair a child s ability to function across environments. The finding that only 7 items on the Sensory Profile met the criterion for a behavior to be considered common confirms the above. 5 items on the Sensory Profile though did not meet the criterion for a behavior to be considered common, were exhibited always or frequently more than 50% of times (items * Table2). All twelve items that were significant demonstrated behaviors which children with learning disability display often as part of the clinical picture. Gender Comparisons on the Sensory Profile Fifteen items, distributed among five categories of the Sensory Profile, for typical children, represented gender differences. For children with learning disability gender differences were evident on twelve items distributed among seven categories of the Sensory Profile. Follow up univariate testing revealed that several individual items contributed to the significance levels of the categories (F<0.05)). The following items are common for both typical children, and children with learning disability but the frequency distribution was significantly different between the groups. Auditory 2-is distracted or has trouble functioning if there is lot of noise, Auditory 6-can not work with background noise, Touch 9-picky eater, especially regarding textures. In typical children, girls are more likely to display these behaviors on eight items while boys on seven items. In contrast in the sample of children with learning disability except for one item (Touch 9) were girls are more likely to 67

6 exhibit this behavior all other eleven items boys performed significantly. Boys are more likely to display majority of items because they generally attempt to seek sensory stimulation more than girls, which is their style of interaction in the environment Dunn. W. (2001) 12. The gender significance can also be attributed to some items being considered a desirable trait by the parent. Large number of boys in both samples as especially in the group of children with learning disability could also contribute to the results. Age Comparisons in Typical Children The data comparing younger and older children indicate they performed differently on all categories of the Sensory Profile. Follow up univariate testing revealed that several individual items contributed to the significance levels of the categories (F<0.05)). There was a significant difference in Auditory=2 items, Visual =3 items, Taste/ Smell = 1 item, Movement=6 items, Touch = 6 items, Activity level = 2 items, Body position =1 item, and Emotional / Social =6 items. Younger children were more likely to display these behaviors except Movement 15- prefers sedentary activities ; Touch 5-is sensitive to certain fabrics ; and Emotional / Social 11- is stubborn and uncooperative. Younger children are more likely to exhibit these behaviors in twenty four of the twenty seven items significant for typical children and thirty two of the thirty three items significant for children with learning disability. The significant differences between younger and older children reflects the developmental trends on the Sensory Profile, e.g. Visual8, younger children usually have more difficulty controlling writing and drawing equipment like pens and pencils than do older children since they are just developing eye hand coordination. Older children begin to differentiate the range of sensory input and learn about becoming part of the external world much faster than younger children. Children from an early age start experiencing sensations. As they grow and develop they accumulate information and then habituate to some sensory events and these events become familiar patterns to the nervous system. This can be one of the possibilities for younger children performing more significantly than older children on the Sensory Profile. Differences between younger and older children can also be attributed to some of the items being considered a desirable trait by the parent. Functional Level Comparisons in Children with Learning Disability The data comparing low and high functioning children with learning disability indicated they performed differently on all eight categories of the Sensory Profile. Follow up analysis was done only on those items that met the criterion (for a behavior to be considered common) and items which were exhibited always or frequently 50% or more of times in children with learning disability. Low functioning children exhibited these behaviors always or frequently more often than higher functioning children. Clinical Implication The sensory profile relies on parental report of observed behaviors and the frequency or intensity of behaviors within the child s natural environment. Thus its use encourages parental involvement in the evaluation process. Since the Sensory Profile highlights the behaviors interfering with the child s functioning, the measure can be useful to therapist in planning contextually relevant interventions. The fundamental characteristics of behavior and personality identified by the Sensory Profile help to define the most effective style of interacting with the child. Limitation and Directions for Future Research The use of convenience samples for the two groups of children and the vast discrepancy in sample sizes was noted. A larger sample with equal distribution of gender and age variables would allow further analyses that might be useful in better understating the appropriateness of the sensory profile items on a broader population. The Sensory Profile analysed only the items data and not each of the items. Examination of the groups of items in a particular category will help validate the placement of items into that category after the individual categories are validated. For example, a behavior such as becomes anxious or distressed when feet leave the ground (Movement 1) was placed in the movement category but may be associated with the Emotional / Social category in factor analysis. The information gathered from parents about their children s performance in daily life lets us build a body of knowledge that includes information about children with and without learning disability. Comparative studies to identify unique patterns of performance from one disability group to another would assist is referral, diagnosis and program planning. Discriminate analysis among groups with various disabilities might assist in identifying a small number of items on the Sensory Profile that could serve as screening tool for other professionals and agencies as they determine who to refer to occupational therapy for further evaluation. CONCLUSION The Sensory Profile appears to be valuable communication 68

7 vehicle for explaining a child s sensory responsiveness. It has the potential to contribute information about a child s sensory processing skills that affect performance. This study has shown that the Sensory Profile is able to distinguish between children with and without learning disability. It helps us to understand a child s sensory processing in relation to his performance at school, home and with peers. It also helps others to understand the child s sensory processing problems, promote tolerance of the child s behavior, focus on the difficulties he or she will be experiencing and make effort to increase his or her self esteem and mastery. REFERENCES 1) Bennette, J.W; Peterson, C.Q. (1995). The Touch Inventory For Elementary School- Aged Children: Test Retest Reliability And Mother child Correlation s. American Journal of Occupational Therapy, 49, ) Bird, H.R., Canino, G., Rubio-Stipee, M; Ribera, J.C. (1987). Further Measures of the Psychometric Properties of the Children s Global Assessment Scale. Arch of Gen Psychiatry, 44, ) Blythe, S.G; Hyland, B.(1998). Screening for Neurological Dysfunction In the Specific Learning Difficulty Child. British Journal of Occupational Therapy, 61, ) Clark, G.F.(1994). Clinical Interpretation of Performance of Typical Children on the Sensory Profile: An Item Analysis. American Journal Of Occupational Therapy,48, ) Cohn; E.S. (2001). Parent Perspectives of Occupational Therapy Using. A Sensory Integration Approach. American Journal of Occupational Therapy, 55, ) Dunn, W.(1994). Performance of Typical Children on the Sensory Profile: An Item Analysis. American Journal of Occupational Therapy, 48, ) Dunn, W; Westman, K.(1997). The Sensory Profile: The Performance Of a National Sample of Children without Disabilities. American Journal Of Occcupational Therapy, 51, ) Dunn,W;Brown,C;(1997). Factor Analysis on the Sensory Profile From a National Sample of children without Disabilities. American Journal of Occupational Therapy, 51, ) Dunn,W; (2001). The Sensations of Everyday Life: Empirical, Theoretical, and Pragmatic Considerations. American Journal of Occupational Therapy, 55, ) Ermer,J;Dunn,W.(1998). The Sensory Profile : A Discriminant Analysis of children with and without Disabilities. American Journal Of Occupational Therapy,55, ) Hooper, S.R. (1996). Subtyping Specific Reading Disabilities : Classification Approaches, Recent Advances and Current Status. Mental Retardation and Developmental Disabilities Research Reviews 2, ) Johnson-Ecker, C.L; Parham, L.D. (2000). The Evaluation of Sensory Processing: A Validity Study using Contrasting Groups. American Journal of Occupational Therapy, 54, ) Kientzs,M.A; Dunn,W.(1997). A Comparison of the Performances of children with and without Autism on the Sensory Profile. American Journal of Occupational Therapy, 51, ) Lyon,G.R; Chhobra.(1996). The Current State of Science and The Future Of Specific Reading Disability. Mental Retardation and Developmental Disabilities Research Reviews, 2, ) Mulligan,S.(1996). An Analysis of score Patterns of children with Attention Disorder on the Sensory Integration and Praxis Test. American Journal of Occupational Therapy,50, ) Mulligan,S.(1998). Patterns of Sensory Integration Dysfunction : A Confirmatory Factor Analysis. American Journal of Occupational Therapy, 52, ) Reynolds, A.M; Elksnin, N; Brown III, F.R.(1996). Specific Reading Disabilities: Early Identification and Long-term Outcome, Mental Retardation and Developmental Disabilities Research Reviews, 2, ) Shaffer,D; Gould, M. S. Brasic, J; Ambrosini, P; Fisher,P; Bird, H. R; Aluwahlia. S. (1983). A Children s Global Assessment Scale (CGAS). Arch Gen Psychiatry, 40, ) Shaffer, D; Gould; M. S; Bird, H. R ; Fisher. P. Children s Global Assessment Scale. Epidemiological Shedy of Children and Adolescent Psychiatric Disorders in Urban and Rural Areas. Task Force Project ICMR. 20) Shapiro, B.K (1996). The Prevalence of Specific Reading Disability. Mental Retardation and Developmental Disabilities Research Reviews, 2, ) Smith, J. C. (1997). Clinical Interpretation of Factor Analysis. On the Sensory Profile from a National Sample of Children Without Disabilities. American Journal of Occupational Therapy, 51, ) Watling, R. L; Deits J; White, O. (2001). Comparison of Sensory Profile Scores of young Children with and without Autism Spectrum Disorders. American Journal of Occupational Therapy, 55, ) Ayres, A. J. (1993). Sensory Integration and Learning Disorders. (2 nd edn). Los Angeles, CA : Western Psychological Services. 24) Ayres, A. J. (1985). Sensory Integration and the Child. (7 th edn). Los Angeles, CA: Western Psychological Services. 25) Clark, P. N; Allen, A. S. (1985). Occupational Therapy for children St. Louis: C. V. Mosby Company. P ) Fisher, A. G. Murray, E. A.; Bundy, A. C. (2001). Sensory Integration: Theory and Practice. (2 nd edn). Philadelphia : F. A. Davis 27) Gelder, M; Gath, D; Mayor, R; Cowen, P.(1996). Oxford Textbook of Psychiatry. (3 rd edn). New York : Oxford University Press Inc. P ) Hopkins, H. L.; Smith, H. D. (1993). Willard and Spackman s. Occupational Therapy. (8 th edn). Philadelphia : J. B. Lippincott Company. P ) Kramer, P., Hinojosa, J. (1993). Frames of Reference for Pediatric Occupational Therapy. Maryland : Wiliams & Wilkins. P ) Partridge, C. J.; Barnit, R. E (1986). Research Guidelines : A Hand book For Therapists. (1 st edn). London: Heinemann Medical Books. 31) Rutter, M ; Hersov, L. (1987). Child and Adolescent Psychiatry. (2 nd edn) London : Blackwell Scientific Publications. P ) Sadock, B. J ; sadok, V. A. (2000). Comprehensive Textbook of Psychiatry. (7 th edn). New York : Lippincott Williams & Wilkins. Vol. 2, P l 69