Neuropsychological assessment and its role in the functional outcomes of children with ADHD - Pritchard et. al. - 2012 - Article

Increasingly, the effectiveness of clinical services must be justified by scientific evidence in order to be considered as an option for treatment. The necessity of evidence-based services has becoming more and more important for psychologists as well as physicians. Currently, there’s a lack of effectiveness data on neuropsychological assessment in ADHD. Therefore, the question’s raised whether neuropsychological assessments contribute to improved accuracy in diagnosis and to better outcomes than diagnoses made on the basis of clinical observations, rating scales and/or constructed interviews.

Neuropsychological assessment is defined as the evaluation of a child by a trained neuropsychologist. This considers the following skills, as appropriate to the case in question:
general intelligence and academic achievement, executive functions, attention, memory, motor skills, visual processing, language processing, adaptive skills, sensory and perceptual skills. Behavioral, emotional and social functioning are also part of the evaluation. This is accomplished by methods such as a clinical and history interview, observation, a flexible battery of standardized instruments and behavior and skill ratings completed by the patient itself and its family and teachers. In contrast to ADHD, more evidence exists for the effectiveness of neuropsychological assessment for other medical conditions such as epilepsy, neuro-oncology and traumatic brain injury.

It’s quite complex to diagnose a child with ADHD, because many symptoms observed in children with ADHD are also common among other behavioral and emotional disorders. The diagnosis is especially difficult in girls, due to later age of onset and more subtle clinical manifestations. Some of the co-occurring disorders which are regularly seen in combination with ADHD are anxiety disorders, depression, autism spectrum disorder, Tourette syndrome and pediatric Bipolar disorder. Sometimes there’s even co-occurrence between ADHD and multiple other disorders.

When other causes for behavioral and emotional symptoms haven’t been considered, the accuracy of an ADHD diagnosis can be questioned. If the child isn’t properly diagnosed, the treatment is likely to be less effective and more expensive. When co-occurring conditions aren’t recognized, children may not get the treatment they need and provided treatments for ADHD may be less effective. An extensive neuropsychological assessment evaluates all functional domains and generates recommendations for treatment of ADHD that consider co-occurring conditions. Where visits to the routine pediatric or general practitioners often don’t include a broad-based evaluation of a child’s overall functioning, neuropsychological assessments offer recommendations addressing areas of need that include the three most important agents of change in the life of a child: family, school and treatment providers.

Prevalence of ADHD in children

ADHD is the most commonly diagnosed disorder in child psychiatry, and the prevalence of ADHD continues to grow. The disorder is more common among boys, they are diagnosed with ADHD twice as much as girls. Prevalence increases with age. There’s little to no difference in prevalence rates between white, black and Hispanic children. Diagnoses among Mexican children are considerably lower. Rates of diagnosis are consistent between North America, South America, Europe, Asia, Australia and the South Pacific. They differ from rates found in Africa and the Middle East. The rate of ADHD diagnosis is also associated with socioeconomic factors such as growing up in an impoverished community and living in a single parent household. The prevalence also varies by subtype, although this is difficult to interpret because subtypes generally change over time.

ADHD: Structural and Functional Brain Differences

Children with ADHD show structural brain differences such as total brain volume and delayed cortical maturation. This is especially seen in the frontal and temporal brain regions in combination with abnormalities within the corpus callosum, temporal and parietal cortex, prefrontal regions and as the most consistent finding an abnormal development of the basal ganglia. The latter is associated with the behavioral phenotype of children with ADHD. The neuroanatomic differences observed in children with ADHD are related with deficits in motor skills and eye coordination. They can also explain the often experienced deficits in children with ADHD regarding inhibition and temporal processing. Given these considerations, structural and functional developmental brain differences in ADHD emphasizes the involvement of multiple neural systems which all contribute to very complex symptoms of the disorder. Conditions that coexist with ADHD, such as Developmental Coordination Disorder (DCD) and developmental dyspraxia, may not be assessed without the use of neuropsychological examinations.

Behaviorally-Based Diagnoses and its Inherent Difficulties for Clinical Neuropsychology

For the classification of childhood disorders in the clinical setting, child neuropsychologists use two general approaches: one emphasizing behavior and the other emphasizing neurology. Seen from the behavioral perspective, developmental disorders are classified on the basis of behavioral or cognitive symptoms alone, without paying attention to its etiology. This mostly happens using the DSM. It often occurs though that children with known neurological impairment show symptoms of several behavioral disorders, but do not fit in the full diagnostic criteria for a single disorder. Moreover, the DSM criteria rarely provide information about the developmental nature of childhood disorders such as ADHD. Neuropsychological assessment offers a thorough consideration of all of the presenting symptoms, allowing for a better understanding of the interconnections among symptoms and working towards more effective treatment recommendations.

Primary Care Settings and the Diagnosis of ADHD

At least half of the individuals diagnosed with ADHD are identified and treated within primary care settings instead of a mental health professional. Therefore, the American Academy of Pediatrics (AAP) has set some guidelines for the assessment and diagnosis ADHD. This concerns the following:

1. Documentation of the DSM-criteria

2. Evidence of the core ADHD symptoms, manifested as well at school as at home

3. Evaluation of possible coexisting conditions

These guidelines further state that neuropsychological tests are not obligated for the diagnosis of ADHD, but that they should be performed when there is not enough information about a patients history, when they show low academic achievement or low cognitive abilities. Research unfortunately shows that most of the time the AAP guidelines are not completely followed within primary care settings. This seems to have to reasons. First of all, many pediatricians receive limited mental health training. Second, there isn’t enough time in routine visits to conduct an assessment that would adhere to the guidelines. Because most ADHD patients get diagnosed within primary care settings, considering the findings above, we can call into question the accuracy and completeness of diagnosis for the majority of individuals of ADHD.

Currently, the diagnosis of ADHD is made by exclusion, so by ruling out other conditions that could explain the patients behavior and complaints. Considering that ADHD occurs more often with comorbidities than without, this strategy is questionable. Standardized psychometric tests alone are also not sufficient enough for making a reliable diagnosis but use of this tests could increase the validity of the diagnostic decision-making process in combination with observation, parent and teacher ratings, interviews and the history of the child.

Behavior and outcomes associated with ADHD

Social cognition seems to be impaired among children with ADHD. Therefore they often have trouble functioning in social situations and making friends with peers. Children with ADHD also less often show prosocial behavior such as turn-taking, sharing and cooperation. Moreover, they show higher levels of problematic social behavior such as impulsivity and aggression. Consequently, they do not only have trouble with making friends but also experience more conflict with their parents. Their parents themselves show a loss of confidence in their parenting skills, poorer coping and experience a lot of stress.

Compared with typically developing children, those with ADHD are more likely to receive special education services, be retrained at higher rates, drop out of school, have a lower grade point average and receive more suspensions and expulsions. College students with ADHD have a lot of trouble organizing and planning. Subsequently, individuals with ADHD experience poorer employment outcomes and therefore tend to attain lower socioeconomic status.

Adolescents with ADHD are at increased risk for developing substance use disorders. The disorder develops earlier in life in individuals with ADHD and they have more trouble with cessation. A conduct disorder seems to mediate the association between substance abuse and ADHD, and further research has shown a link between certain genes that people with substance abuse and people with ADHD have in common. Considering this information, it is not surprising that adolescents with ADHD are also at a higher risk for involvement in criminal activity.

Children with ADHD use the health care system more often and make higher costs than children without the disorder. They visit the emergency room more frequently and are more likely to be hospitalized. Their injuries are mostly more severe and often the cause of their impulsivity. Family members of the children with ADHD show higher costs due to disability and absenteeism. Most of the extra costs that children with ADHD make for society and themselves can be attributed to the treatment of co-occurring conditions rather than the treatment for ADHD itself. Because a neuropsychological assessment can show a child’s strengths and weaknesses, provide a good differential diagnosis and thorough interventions, a lot of money can be saved for the individual with ADHD as well as society as a whole if we would use this kind of research more often.

The Quality of Life for an individual with ADHD seems particularly affected by psychosocial and achievement-related aspects. In comparison with children with chronic physical conditions, children with ADHD experience equal, and sometimes even greater reductions in many domains of the Quality of Life. Their parents also show some impairments in their Quality of Life.

There are several treatments for ADHD that have shown to reduce symptoms and that induce functional improvement. The best known alternative is stimulant medication, followed by psychotherapeutic treatments and educational support services. In contrast with the findings that these treatments reduce symptoms, studies clearly indicate that treatment for the ADHD population is not being optimized, as many individuals with ADHD show both symptoms and functional impairment despite of receiving treatment. This is often due to the fact that many of the positive effects that are found in the beginning of the treatment quickly dissolve. When the intensity of the treatment is reduced, symptoms and functional impairment return. The treatments thus may not be targeting all of the appropriate domains or disorders necessary to create a longstanding change.

Recently, a lot of different studies have been done regarding medical treatment, and their general conclusion was that treatment with medication has the potential to reduce symptoms and high-risk behaviors and improve the quality of life, though not consistently or completely. Furthermore, psychopharmacological treatment reduces the core symptoms of ADHD, but do not have this desired effect on co-occuring impairments. The same goes for behavioral treatment. Considering these findings, it is safe to suggest that even when treatment reduces symptoms, if it’s not specifically designed to address other areas of impairment or concern, quality of life will still be impacted. Here lies a chance to use neuropsychological assessment, as it has the potential for a better understanding of the symptomatology of ADHD and co-occurring disorders. You have to know someone’s strengths and weaknesses in order to make recommendations for optimizing treatment to address all factors included, and this is something neuropsychological assessment can offer.

Conclusion

Thorough neuropsychological assessment of children suspected having ADHD can offer the following benefits:

1. Use of a wide variety of measures so there’s an understanding of the child as a whole

2. Consideration of co-occurring conditions and disorders

3. Optimized recommendations for treatment

4. Psychometrically-defined baseline level of functioning against which treatment effects can be measured