This set of summaries concerns, firstly, the issue of identification and the need for multi-observations and ratings of behaviour, and for care in identifying the precise pattern of needs when comorbid conditions are present.
Reference is then made to neurological structure and the interaction between right hemisphere anomalies and ADHD typology.
The following section concerns children with ADHD and their typical response to reinforcement schedules (with implications for a need to avoid reward delays); and the final section introduces the possibility that yoga-based exercises could offer an alternative to medication or difficult-to-supervise behavioural programmes.
The work of Evans et al (2005) provides a reminder of some of the pitfalls that may operate when it comes to determining when a child’s observable performance would legitimately be seen as indicating actual AD(H)D.
For example, there is converging evidence and associated advice to the effect that observations on single occasions or in single settings may not give a valid impression of the child’s behaviour and style and, accordingly, that the diagnosis (or non-diagnosis) should be based upon information from a number of sources and upon more than one observation occasion and/or setting.
These current authors examined the agreement among teachers’ ratings and observations in a middle school setting collected on a regular basis over the course of two academic years in respect of children diagnosed with ADHD.
Their results indicated low inter-rater agreement, and low rates of correspondence between the teachers’ ratings and observational data, and low agreement between observational data gathered in different classrooms.
The level of agreement was lowest during the first term of the school year and gradually increased during the second half.
The implication reinforces the need for caution in determining whether or not a diagnosis of ADHD is justified, and for maximising the information from the school staff upon which the decision is largely or at least partially based …. i.e. ratings should be gained from all the teachers who are involved with a given child and observational data from different settings and situations.
(It might also be noted that this kind of multi-source evidence would be valuable not only in diagnostic decision-making but also in gaining some insight into the temporal or situational nature of the difficulties. Are the symptoms most marked during a particular time of the day, or in particular types of tasks and according to levels of structure, or among a given group of peers, or with given teachers and subjects/activities within the timetable ?)
The complexity involved in gaining a clear picture of the nature and severity of a child’s difficulties was also noted by Pfiffner et al (2005).
Their interest was in possible or probable comorbid conditions alongside ADHD which were held to be of major importance since the precise nature of the appropriate intervention “package” would be influenced by the individual profile of difficulties.
In particular, they sought to differentiate family factors (such as negative parental management strategies or actual parental pathology) which could underlie comorbid oppositional defiant disorder from those factors which were linked to conduct disorder within the children already diagnosed with ADHD.
Their study involved the assessment of the clinic-referred children (N=149) using the strict DSM-IV criteria, and an analysis of parental handling practices.
The findings indicated that comorbid oppositional defiance and conduct disorder were significantly associated with ineffective or negative disciplinary strategies on the part of the mothers.
Conduct disorder (but not oppositional defiance) was associated with a lack of maternal warmth or involvement, with negative or ineffective discipline from the fathers, or with an anti-social personality typing of the fathers.
It was concluded that consistent management was important for dealing with the comorbid oppositional defiance and conduct disorder, but also that pathology among the fathers and the (poor) quality of mother-child interactions could also play a role in the development or maintenance of conduct disorders.
The implication was for family work to accompany any intervention focusing upon within-child factors in order to increase the likelihood of consistency of approaches to the child and of maximising the affective qualities within the relationship between parents and child … (notably the primary care-giver and the child).
The research by Miller et al (2006) sought to link the issues of social comprehension with right hemisphere deficits and with ADHD.
The argument was that the right hemisphere has been linked with social skill and empathy limitations, while ADHD has also been associated with social difficulties, with the possible implication for the differentiation of a subtype, almost a syndrome, of ADHD where there is evidence for right hemisphere dysfunction or damage, and evident social skill weaknesses particularly in the area of verbal and non-verbal communicative sensitivity.
There is a pattern whereby children with ADHD are not readily accepted by peers, perhaps because of their fleeting attention and erratic responsiveness.
The authors describe the typical pattern of development in that the early school years are marked by gradually learning how to evaluate social situations and how to respond, thus to make and maintain positive peer relationships. Problems at this stage will underlie a failure to develop more complex social skills.
During middle and later childhood, there is the growth of self regulation in response to social signals from peers and others, with the capacity to modify behaviour to meet the particular circumstances.
Meanwhile, the introductory review continues, brain structures have been the target for the assessment of social skill deficits, notably the right hemisphere where damage has been consistently linked to a lack of social perception and empathy as illustrated by poor eye contact, misinterpretation of social cues, inappropriate use of non-verbal signs, and poor language expression.
There is also converging evidence for an association between right hemisphere abnormalities and signs of ADHD such as a pattern whereby children diagnosed with ADHD differ from normally developing peers in having a greater caudate volume in the right hemisphere than in the left.
The study by Miller et al (op.cit) explored whether differences in the pattern of severity of social comprehension weaknesses could be observed in children with right hemisphere anomalies and those without this complication; or whether social comprehension ability could be a further criterion for differentiating ADHD subtypes.
An associated question concerned the possible effects of the interaction of brain morphology and ADHD subtype upon social comprehension skills.
The study involved a large sample of children, between the ages of 6 and 12 years, referred for assessment of learning problems. Many of the children met the criteria for reading disability, 43% for ADHD, and there were associated weaknesses in language and emotional adjustment.
The children were assessed in respect of the DSM-IV classification of ADHD and the majority also underwent an MRI scan. Social comprehension was rated by parents using a variant of the Behaviour Assessment Scale for Children.
The results indicated that age was not significantly correlated with social comprehension scores thus ruling out the possibility that age could be the confounding variable in predicting the level of this social skill.
Meanwhile, ADHD typology was salient in that the combined type of ADHD, but not the primarily inattentive type, was associated with poor social comprehension compared to controls.
No significant differences in social comprehension were found between children with typical versus atypical brain morphology per se. Differences were noted when the analysis involved a comparison of children with and without the atypical morphology and with or without a diagnosis of ADHD.
In other words, right hemisphere structural anomalies are associated with greater social difficulties in the case of children who already have shown symptoms of ADHD. Morphology alone is a not a significant factor, but can be significant in increasing social weaknesses when interacting with the underlying mechanisms of ADHD.
In summary, children without ADHD showed better social comprehension than children with the combined form of ADHD, with children showing the primarily inattentive type producing social ratings somewhere midway between these two.
Brain morphology did not in itself underlie differences in social comprehension, although children who had both an ADHD diagnosis and atypical right hemisphere structure had significantly poorer social comprehension than the children without ADHD but with the atypical hemispheric structure.
The children with the interacting factors are more at risk for a failure to develop social skills such as awareness of, and concern for, others’ feelings, listening, and appropriate responding.
One would usefully draw the implication that children already recognised as having signs and symptoms of ADHD would benefit from further attention (such as the teaching and modelling of social skills, or being targeted for Circles of Friends’ activities) if they also display clear weaknesses in respect of social perception and comprehension.
Intervention (Reinforcement Schedules)
Some atypical pattern of (response to) motivational factors has been cited as a possible explanation for the behavioural symptoms and the performance deficits of children with ADHD.
For example the work of Douglas and Parry (1994) led to a summary indicating that children with ADHD show an increased need for reinforcement, especially immediate and tangible reinforcement, but can be distracted or aroused by those reinforcers, and can become highly frustrated when anticipated reinforcers do not materialise.
A recent, dynamic view explored by a number of researchers, and set out by Aase and Sagvolden (2006), holds that the behavioural symptoms of ADHD may be explicable in terms of a shorter than normal delay-of-reinforcement tolerance.
The theory about delay of reinforcement suggests that reinforcement affects not only the response which gives rise to it, but also the longer-term behaviour leading up to that point. The implication is that any delay will negatively impact upon the effectiveness of the reinforcer, and the positive effect will be upon the immediately preceding response rather than upon behaviours that occurred earlier.
This is thought likely to inhibit the development of sustained attention, and children with this short delay “gradient”, or lack of self control, will not have the chance to experience the benefit of waiting for larger rewards because they focus upon the immediate albeit smaller rewards (thus demonstrating an impulsiveness).
Converging evidence is cited to highlight how children with ADHD usually appear to need reinforcement for each correct response and tend not to maintain the appropriate behaviour if the reinforcement is partial. It is common, although not always the case, that such children prefer an immediate and small reward rather than a larger reward available after a delay so that their behaviour is less controlled by overall reinforcement contingencies but influenced by the nearest reinforcer at any given time.
Further, the children with ADHD have a preference for tangible rewards such as a sweet, while non-ADHD children appear equally or more motivated by social rewards such as teacher praise or by some intrinsic reward such as the knowledge of having achieved the right answer. The implication is that observed lack of success with a behavioural intervention may be attributed to the use of reinforcers (such as tokens, or verbal praise) which are not sufficiently or immediately rewarding to the children.
The study by Aase and Sagvolden themselves investigated the prediction that hyperactivity, impulsiveness, and a lack of sustained attention will be the more marked when rewards are infrequent.
They used a computer game where only one of two possible responses to the stimulus presented was linked to a reward in the form either of access to cartoon pictures on the screen or the cartoons accompanied by a tangible reinforcer. Reward frequency was varied by alternating short and long variable interval schedules.
A sample of children aged between 6 and 12 participated as the target group (meeting the criteria for ADHD) and they were compared with a control group of children with no known diagnosis.
Assessments involved ratings of behaviour by parents and teachers; tests of cognitive functioning; and clinical evaluation of the level of symptoms associated with ADHD (and any comorbid difficulties such as oppositional defiance or conduct disorder).
The main findings indicated that differences between the two groups were most evident in their efforts when reinforcer frequency was low. When the “density” of reinforcement was high, the two groups were not significantly different on measures of activity, or impulsiveness, or attention.
In other words, the prediction about reward availability and ADHD children was supported.
The authors went on to speculate that a short and steep delay gradient could underlie this situation. When a reward is immediate, the effect is greatest for both ADHD children and controls; but the effect of the reward will decay much faster among the ADHD group so that there will be less of an impact upon their behaviour when the rewards available are subject to delay.
A second finding was that the effect of varying the reward schedules more readily discriminated ADHD children from controls when age was taken into account.
This may have been explicable in terms of the reduced value of the rewards, or the perceived childishness of the rewards, in the eyes of the older children … especially the non-ADHD sample.
However, the authors cited the common view that the response to rewards among ADHD children tends to remain immature; and their own results suggested that the ADHD sample were more likely to persist in finding value in tangible reinforcers such as sweets or stickers.
Their third finding involved the variability of reaction in the ADHD sample when rewards were infrequent. Responses immediately preceding a reward were reinforced in the ADHD sample, but other and dysfunctional responses were less likely to be extinguished and remained part of the response “repertoire” such that a range or an unpredictability of behaviours was a characteristic of this sample of children.
The learning curve typical of the ADHD children would have been predicted by the earlier described dynamic theory of ADHD which holds that learning the association between a discriminating stimulus, a correct response, and the reinforcing consequence will be inhibited because of the delay gradient. Sustained attention is influenced by the pattern of rewards.
The day to day implications involve support for the view that behaviour modification programmes need to emphasize the use of immediate and frequent rewards of a kind that are valued by the children. Clear and unambiguous rules need to be set with a close association maintained between the child’s following of the rules and this being both noticed and rewarded.
It may even be that frequent reinforcers can act like weak doses of psychostimulants. What matters is that there is a match between environmental contingencies and manipulated reinforcement mechanisms …. clear rules for in-class actions, immediate and frequent reinforcers for good behaviours, and predictable consequences for poor behaviours.
A study by Peck (2005) was based upon the perceived need to increase the range of interventions for ADHD given the variable response to medication (as well as some ethical concerns) and likely difficulties in maintaining the consistency of behavioural programmes. There is also the concern lest the effects of such interventions may not be fully sustained once the direct action is tailed off.
Nevertheless, the adverse effects upon children’s scholastic and social progress of ADHD are such as to require clear action.
Peck describes an alternative approach based upon the use of elements of Yoga including work on physical posture, breath control, mental concentration, and relaxation by which to enhance self control.
The experimental group included 10 children between the ages of 7 and 10 years referred by teachers for clinical services because of observed problems with attention.
Use was made of a videotape providing adult and child models of activities and exercises concerned with breathing, posture, and relaxation exercises, concluding with guided imagerv sessions where the children were assisted to create positive and peaceful mental scenes. A baseline period by which to gain a measure of typical behaviour was followed by a 3-week intervention phase, with a follow up after a further 3 weeks.
Results indicated that the substantial differences between the targeted children and peers observed initially (in on-task behaviours) reduced markedly during the intervention so that on-task rates in these children were largely the same as the rest of the children in the classes.
At the follow up, there was observed to be some return to a greater off-task tendency among the children in question, but behaviour was still much more positive than during the baseline period.
The limitations in terms of small sample size, and the possibility of bias (given that the researcher both delivered the intervention and gathered the behavioural data), are acknowledged but independent observations confirmed the positive change; and it was concluded that Yoga principles could provide an alternative intervention and that it would seem legitimate to support further pilot studies involving larger samples and greater controls (to investigate, for example, if it is the Yoga itself which matters or some kind of placebo effect along with enhanced adult attention).
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Aase H. and Sagvolden T. 2006 Infrequent, but not frequent, reinforcers produce more variable responding and deficient sustained attention in young children with ADHD. Journal of Child Psychology and Psychiatry 47(5) 457-471
Douglas V. and Parry P. 1994 Effects of reward and non-reward on frustration and attention in attention deficit disorder. Journal of Abnormal Child Psychology 104 232-240
Evans S., Allen J., Moore S., and Strauss V. 2005 Measuring symptoms and functioning of youth with ADHD in middle schools. Journal of Abnormal Child Psychology 33(6) 695-706
Miller S., Miller C., Bloom J., Hynd G., and Craggs J 2006 Right hemisphere brain morphology, attention deficit hyperactivity disorder subtype, and social comprehension. Journal of Child Neurology 21(2) 139-144
Peck H. 2005 Yoga as an intervention for children with attention problems. School Psychology Review 34 415-424
Pfiffner L., Mcburnett K., Rathouz P., and Judice S. 2005 Family correlates of oppositional and conduct disorders in children with attention deficit/hyperactivity disorder. Journal of Abnormal Child Psychology 33(5) 551-563
© Mike Connor 2006.
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