DIAGNOSIS ERROR OR COMORBIDITY OF PERVASIVE DEVELOPMENTAL DISORDER AND ATTENTION DEFICIT/HYPERACTIVITY DISORDER IN SMALL AGES?
In clinical practice frequent we meet children with polymorphic symptoms: delay in language development, deficits in social interaction, repetitive behaviours or interests, hyperactivity, major attention deficit, poor eye contact, idiosyncratic appetite, echolalia, stereotype play. All these symptoms lead to a lot of disagreement about nosological enframe: PDD (Pervasive Developmental Disorder) or early onset of ADHD (Attention Deficit/Hyperactivity Disorder)?
- 19,74 % of the sample was diagnosed with Autism Disorder,
- 10,53 % with Autistic Spectrum Disorder and
- 69,74% with Delay in language development (LDD).
Introduction
In clinical practice frequent we meet children with polymorphic symptoms: delay in language development, deficits in social interaction, repetitive behaviours or interests, hyperactivity, major attention deficit, poor eye contact, idiosyncratic appetite, echolalia, stereotype play. All these symptoms lead to a lot of disagreement about nosological enframe: PDD (Pervasive developmental disorder) or early onset of ADHD (Attention Deficit/Hyperactivity Disorder)?
Both ICD-10 and DSM-IV state clearly that ADHD should not be diagnosed in the presence of a pervasive developmental disorder (autism spectrum disorder; ASD). Yet in clinical practice we know that ADHD is commonly comorbid with PDD and requires treatment. For these reasons the NICE guidelines clarify that it is possible to have both ADHD and PDD and that the diagnosis of ADHD should be made on the basis of the core syndrome, regardless of comorbidity. In clinical practice this is already implemented by most specialists (Sinzig et al, 2008).
There is good evidence that PDD and ADHD can be separate and recognisable ‘‘disorders’’, but the overlapping in different aspects of problems was invocated by many study (Goldstein et Schwebach, 2004; Reiersen et al., 2007).
In 1990, Gillberg and his collaborators have demonstrated, working with a group of children diagnosed with autism before age 3 years that the autism were relatively stable over time, 75% still meeting criteria for PDD at follow-up years later. However, in 25% this was not the case, but all the children in this latter group met criteria for another developmental disorder, such as non-autism learning disability or ADHD (Gillberg et al., 1990). Other groups (Chawarska, et al., 2009) have found similar results.
In a study of more than 300 preschool children with a clinical diagnosis of PDD, the vast majority met research DSM-IV criteria for autistic disorder, Asperger’s disorder, or pervasive developmental disorder not otherwise specified at follow-up after 2 years. However, about one in 10 was not diagnosed with PDD, but had other developmental disorder diagnoses, such as non-autism learning disability or ADHD. Rates of speech and language problems, ADHD, DCD, gastrointestinal problems, epilepsy, and learning disability in the PDD group varied from about 10% to 60%, but this had not been revealed in connection with the original clinical diagnosis of PDD (Fernell et al., 2010).
In 2010, based on numerous study results, Gillberg has referred to a children category presenting in clinical settings with impairing symptoms before age 3 (-5) years in the fields of
- (a) general development,
- (b) communication and language,
- (c) social inter-relatedness,
- (d) motor coordination,
- (e) attention,
- (f) activity,
- (g) behaviour,
- (h) mood, and/or
- (i) sleep.
The author talks about Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations – ESSENCE, an acronym who encompass under his umbrella syndromes like ASD/PDD, ADHD, Oppositional Defiant Disorder, Slow Language Impairment, Learning Disabilities, Tic disorders/Tourette syndrome, Bipolar disorder, Behavioural syndromes, Rare epilepsy syndromes, Reactive attachment disorder and other developmental disorders.
Autism and other pervasive developmental disorders are brought to clinical attention and are diagnosed on the basis of distinctive disturbances in behaviour and development. There is broad consensus among clinicians and researchers, that autism and associated syndromes represent the surface or phenotypic manifestations of underlying neurobiological diatheses or biological genotypes. (Wolkmar et al., 2005) These conditions are sometimes described as neuro-behavioral or neuropsychiatric disorders, to emphasize their neurobiological underpinnings.
The both are childhood-onset neurodevelopmental disorders affecting key fronto-striatal and fronto-parietal circuits that are important for executive functions (Sinzig et al, 2008). It is likely that the overlapping symptoms among these disorders result from shared foetal mechanisms that interfere with normal cell programming at critical periods during gestation, and that this process is due to multiple environmental, genetic, maternal, and even transgenerational factors. (Zimmerman et Connors, 2010)
Dates from literature suggest that there is an important “genetic overlap” between PDD and ADHD (Gillberg, 2007) and research has continued to suggest that the foetal environment is the staging ground for neurodevelopmental disorders and that these disorders result, in part, from genetic susceptibility influenced by various factors during prenatal life..
PDD and ADHD represent a complex phenotype with a high degree of heritability. Both of them are characterised by behaviour alteration and a similar pattern of “social construct” (Smalley et al. 2006). ADHD symptoms are present in 80% cases of PDD (Pearson et al. 2006) and ADHD and PDD coexist at 50% of patients (Gillberg, 2006).
In some cases, experts point out that autism may be overlooked in children with hyperactivity, and may be unmasked only after the successful treatment of. The chaotic and disorganized style of hyperkinesis may make it harder for the diagnostician to discern the more specific abnormalities of autistic communicative impairment. (Taylor, 2005)
Children with PDDs who have comorbid ADHD often have even more difficulties than other children with autism or Asperger’s in attending to relevant social cues and in controlling impulsive or intrusive behaviors during instruction or social interaction. There is some evidence that the presence of these symptoms are sometimes responsible for a misdiagnosis in which children with high-functioning autism or Asperger’s are mistakenly diagnosed as having only ADHD or delay in language development (Hayashida et al, 2010). Also some times the children with ADHD and some repetitive behaviours or interests may be regarded as autistic because of their severe inattentive.
Objective
The main of this study is to identify using scientifically validated diagnostic tools the percentage of children with PDD in a sample with polymorphic symptoms described above and to evaluate the comorbidity between ADHD and PDD.
Figure 1. Sample’s distribution according to age
Method
We evaluate a sample of 76 children 2.6 – 6.6 years old referred to Child and Adolescent Psychiatry Department, „Prof. Dr. Al. Obregia” Psychiatry Hospital, Bucharest, Romania, for the first time. The principal symptoms of these children were: delay in language development, deficits in social interaction, repetitive behaviours or interests, hyperactivity, major attention deficit, poor eye contact, idiosyncratic appetite, echolalia, stereotype play.
For diagnostic we applied ADOS (Autism Diagnostic Observation Schedule) and ADHD RS (Attention Deficit Hyperactivity Disorder – Rating Scales, parent version). The tests were applied by a clinical psychologist.
After applying the ADOS were obtain the following diagnostic categories: Autism disorder, Autistic Spectrum Disorders and Delay in language development. We consider significant for ADHD a score over 28 points at ADHD RS.
We interpret statistical the dates using SPSS version number 17.
Results
Sample’s distribution according to age is represented in Figure 1.
Sample’s distribution according to gender is represented in Figure 2.
Figure 2. Sample’s distribution according to gender
After applying the ADOS were obtain the following diagnostic categories:
- 19,74 % of the sample was diagnosed with Autism Disorder,
- 10,53% with Atypical autism and
- 69,74 % with Delay in language development (LDD) (Figure 3).
Figure 3. Sample’s distribution according to ADOS score
We considered ADHD as diagnostic if at ADHD RS the score was over 28. A percent of 53.95 % children could be diagnosed with ADHD in our sample (Figure 4).
Figure 4. ADHD distribution
In our sample ADHD was comorbid with:
- Autism disorders in 62.26%
- Atypical autism in 87.5%
Delay in language development in 20% (Figure 5).
ADHD type on Autistic sample:
- 15.09% ADHD hyperactivity – impulsivity type
- 3.77 %ADHD inattentive type
- 43.40% ADHD combined type (Figure 5).
ADHD type on Atypical autism sample:
- 12.5% ADHD hyperactivity – impulsivity type
- 12.5% ADHD inattentive type
- 62.5% ADHD combined type (Figure 5).
In the group of children with Delay in language development the only type of ADHD was the combined type (Figure 5).
Figure 5. Comorbidity with ADHD and ADHD type
Correlation between ADOS and ADHD RS scores was significant (Figure 6)
score ADOS | ADHD-RS | ||
score ADOS | Pearson Correlation Sig. (2-tailed) N |
1
76 |
.279* .014* 76 |
ADHD-RS | Pearson Correlation Sig. (2-tailed) N |
.279* .014* 76 |
1
76 |
Figure 6. Correlation between ADOS and ADHD RS scores
Using Pearson correlation between ADOS scores and ADHD RS scores for hyperactivity-impulsivity, we find a significant correlation (Figure 7).
score ADOS | Hyperactivity-impulsivity | ||
score ADOS | Pearson Correlation Sig. (2-tailed) N |
1
76 |
.263* .022* 76 |
Hiperactivity-impulsivity | Pearson Correlation Sig. (2-tailed) N |
.263* .022* 76 |
1
76 |
Figure 7. Correlation between ADOS scores and ADHD RS scores for hyperactivity-impulsivity
We didn’t fine a significant correlation between ADOS and ADHD RS for inattention (Figure 8).
score ADOS | Inattention | ||
score ADOS | Pearson Correlation Sig. (2-tailed) N |
1
76 |
.152 .191 76 |
Inattention | Pearson Correlation Sig. (2-tailed) N |
.152 .191 76 |
1
76 |
Figure 8. Correlation between ADOS and ADHD RS for inattention
Comorbitidy with ADHD in our sample was more often observed between 4.6 and 5.6 years old (Figure 9).
Figure 9. Correlation between ADHD and age
Conclusions
After applying a diagnostic tools (ADOS and ADHD RS) in a sample with polymorphic symptoms (delay in language development, deficits in social interaction, repetitive behaviours or interests, hyperactivity, major attention deficit, poor eye contact, idiosyncratic appetite, echolalia, stereotype play) we obtain the following results:
- 19,74 % of the sample was diagnosed with Autism Disorder,
- 10,53 % with Atypical autism and
- 69,74% with Delay in language development (LDD).
ADHD was comorbid with Autistic disorders in 62.26% of cases, with Atypical autism in 87.5% of cases and in 20% of cases with Delay in language development.
ADHD combined type predominate both in Autistic sample (43.4%) and in Atypical autism sample (62.5%) and also in Delay in language development sample.
There is a significant correlation between ADOS scores and ADHD RS scores and between ADOS scores and ADHD RS scores for hyperactivity – impulsivity. There isn’t a significant correlation between ADOS scores and ADHD RS for inattentive.
Our findings are in concordance with literatures dates, but the study is limited by the sample’s size. More studies are necessary to evaluate the comorbidity of neurodevelopmental disorders, especially between PDD and ADHD.
BIBLIOGRAPHY
- Chawarska, K., Klin, A., Paul, R., Macari, S., Volkmar, F. (2009) A prospective study of toddlers with ASD: Short-termdiagnostic and cognitive outcomes. Journal of Child Psychology and Psychiatry, 50, 1235–1245.
- Fernell, E., Hedvall, A., Norrelgen, F., Erikssson, M., Ho¨ glund-Carlsson, L., Barnevik-Olsson, M., Svensson, L., et al. (2010) Developmental profiles in preschool children with autism spectrum disorders referred for intervention. Research om Developmental Disabilities, 31, 790–799.
- Fred R. Volkmar, Rhea Paul, Ami Klin, Donald Cohen (2005) Handbook of Autism and Pervasive Developmental Disorders, Third Edition. Volume 1: Diagnosis, Development, Neurobiology, and Behavior. John Wiley & Sons, Inc.
- Gillberg, C. (2006) International developmental Neuropsychiatry Meeting III, „Autism & ADHD Symposium”, Istanbul
- Gillberg, C. (2010) The ESSENCE in child psychiatry: Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examination. Research in Developmental Disabilities 31 (2010) 1543–1551
- Goldstein, S., Schwebach, A.J. (2004) The comorbidity of pervasive developmental disorder and attention deficit hyperactivity disorder: results of a retrospective chart review. J Autism Dev Disord 34(3):329–339
- Hayashida K., Anderson B., Paparella T., Freeman S, Forness S. (2010) – Comorbid Psychiatric Diagnoses in Preschoolers Autism Spectrum Disorders, Behavioral Disorders, 35 (3), 243–254
- Sinzig J., Morsch D., Bruning N., Schmidt M.H., Lehmkuhl G (2008) – Inhibition, flexibility, working memory and planning in autism spectrum disorders with and without comorbid ADHD-symptoms, Child and Adolescent Psychiatry and Mental Health 2:4
- Smalley, S. L., Loo, S.K., Muthen, B., McCracken, J.T., Swanson,J. M. (2006) – Reframing ADHD in the Genomic Era: From Genes to Treatment and Prevention Smalley. American Academy of Child and Adolescent Psychiatry 53rd Annual Meeting, San Diego
- Pearson, I., Beverly A., Wright, W. (2006) – Neurobiology of ADHD, Learning Disorders, and Executive Function Problems: Need for Early Recognition and Treatment. American Academy of Child and Adolescent Psychiatry 53rd Annual Meeting, San Diego.
- Taylor, E. Hyperkinetic disorder, in Gillberg, C., Harrington, R., Steinhausen, H.C. (2005) A Clinician’s Handbook of Child and Adolescent Psychiatry. Cambridge University Press
- Reiersen, A. M., Constantino, J. N., Volk, H. E., Todd, R. D. (2007). Autistic traits in a population-based ADHD twin sample. Journal of Child Psychology and Psychiatry, 48, 464–472.
- Zimmerman, A.W., Connors, S.L. (2010) Maternal Influences on Fetal Neurodevelopment. Clinical and Research Aspects. Springer Science LLC.
Correspondence to:
Child and Adolescent Psychiatry Department, ‘Prof. Dr. Al. Obregia’ Psychiatry Hospital, Bucharest. 10-12, Berceni Street, Bucharest, Sector 4, CP 041 915 florina2rad@yahoo.com