There is a clear need for a new approach to the treatment of obesity, which is inexpensive and is effective for establishing lifestyle change. We conducted a pilot study to evaluate whether dexamphetamine can be used safely, combined with diet and exercise, for treating obesity. Our ultimate aim is to develop a 6-month treatment program for establishing the lifestyle changes necessary for weight control, utilizing dexamphetamine for its psychotropic effect on motivation. We viewed the anorexigenic effect as an additional advantage for promoting initial weight loss.Obese adults were treated with dexamphetamine for 6 months (maximum of 30 mg twice daily), diet, and exercise. Weight, electrocardiogram, echocardiogram, and blood pressure were monitored.Twelve out of 14 completed 6 months treatment. Weight loss by intention to treat was 10.6 kg (95% CI 5.8-15.5, p < 0.001). The mean weight gain in the 6 months after ceasing dexamphetamine was 4.5 kg (95% CI 1.9-7.2, p = 0.003), leaving a mean weight loss at 12 months from baseline of 7.0 kg (95% CI -13.4 to -0.6, p = 0.03). All reported favorable increases in energy and alertness. Dose-limiting symptoms were mood changes (2) and insomnia (2). None had drug craving on ceasing dexamphetamine, and there were no cardiac complications. Among the seven women, there was a significant correlation for those who lost most weight on treatment to have the least regain in the following 6 months (r = 0.88, p = 0.009).Our treatment with dexamphetamine, diet, and exercise was well tolerated and effective for initial weight loss. Future research will focus on identifying baseline predictive variables associated with long-term weight control.
The diagnostic criteria for attention deficit hyperactivity disorder (ADHD) reflect the behavioural and functional outcomes of cognitive processes. Historically they have been based on external observations and lack specificity: clinical cohorts of children meeting diagnostic criteria show that around 40% may also meet diagnostic criteria for oppositional defiant disorder (ODD). We have proposed a clinical model to explain this: the Mental Effort Reward Imbalances model of ADHD (MERIM). This model views the lower levels of task completion that underlie several of the diagnostic criteria for ADHD as being due to a summation of deficits in executive functioning and reward processing. The subjective experience of inadequate reward from task completion may explain the reduced motivation, negativity, and oppositional attitude associated with ODD. The hypothesis for this study is that descriptions of affected individuals' attentional characteristics could be more specific for the executive functioning deficits associated with ADHD than the current symptom-based approaches. To test whether this might be usable in practice, we conducted a workshop that aimed to characterise in depth the patterns of attention experienced by adults with ADHD and how they impact functioning. Three main patterns were described: (1) complete lapses in attention; (2) partial attention to a task; (3) attending to multiple tasks and distractions, either simultaneously or in rapid sequence. All of these resulted in reduced productivity. They also described strategies for managing their attention deficits. Some people used distractions positively, to stimulate the mind to remain active and engaged rather than losing focus. Multi-tasking could also achieve this by providing higher levels of stimulation, however, the stimulation could itself become a distraction. Interest or stress might maintain engagement; extremes could sometimes lead to hyperfocusing, which was typically infrequent but could be highly productive. Focusing on executive functions may improve diagnostic sensitivity, as the current criteria fail to identify people who function adequately due to their use of strategies that mitigate the effects of their attentional deficits. Such people may present with secondary depression or anxiety rather than clear, behavioural symptoms of ADHD. With further development, the approach described in this paper may provide a more simple and fundamental way of recognising ADHD within the community. In the longer term, focusing more specifically on executive functions may provide cohorts with a 'purer' form of ADHD for scientific study.
As paediatricians who work in the adjacent local health district, we were particularly interested in the analysis by Lo et al. of the diagnostic outcomes of children referred to the Parramatta Early Childhood Assessment Team for multidisciplinary assessment.1 They found that of 667 children assessed from 2008 to 2010, 35% were referred for concern about possible autism spectrum disorder (ASD). In the majority of these children (70%), ASD was confirmed. However, in 30% (67 children), the suspicion of ASD was not confirmed. The authors appeared to suggest that these referrals were inappropriate and would extend the waiting time for assessment for others who actually had ASD. ASD can be extremely difficult to diagnose and referrers therefore rely on multidisciplinary assessment services for clarification when there is diagnostic uncertainty. This does not only mean confirming a clinical suspicion of ASD but also in some cases establishing that a child is not autistic and exploring other diagnostic possibilities. We are most interested to know the diagnostic profiles of the children referred for but not diagnosed with autism. It is stated that 40 of these 67 children had language disorders and 9 had no diagnosis (normal development). What were the diagnoses in the remaining 18 children? Also, had any of these 67 children previously been labelled autistic and had to have a retraction of this diagnosis carefully explained to the parents? We are interested to know how many children had previously been incorrectly diagnosed with ASD, together with the breakdown of the professional disciplines of the clinicians making this diagnosis.
To the Editor.—The recent study by Waring and Lapane of 62 887 children diagnosed with attention-deficit/hyperactivity disorder found that those who were not on treatment were more likely to be overweight, defined as a BMI above the 95th percentile, whereas those treated with stimulant medication were more likely to be underweight, defined as a BMI below the 5th percentile.1 This study is impressive in numbers. However, as our own data reflect, the BMI changes seen with stimulant medication are statistically significant but of small magnitude (<1 kg/m2).2 At a cohort level, the effects of stimulant medication are more likely to bring the BMI of the leanest children below the 5th percentile. Lean body habitus is associated with hyperactivity.3 Hyperactive children tend to be more difficult to manage in the classroom and, therefore, might have been more likely to be on stimulant medication at the time of the survey. By contrast, children with inattention are frequently undermotivated to perform any activity and, therefore, prone to be overweight. Therefore, this cohort would be easier to manage in the classroom without stimulant medication. Consequently, BMI might be an indirect indicator for the subtype of attention-deficit/hyperactivity disorder and/or the likely compliance with medication.
Editor – In her interesting educational paper, Frearson reports that hospice placements enabled foundation year 1 doctors to improve their communication skills and enhance their recognition of the dying phase.1 In a very different training environment, we describe involving Australian medical students from the University of Sydney in a community-based study investigating stimulant dose titration in children with attention deficit hyperactivity disorder (ADHD).
Despite its estimated prevalence of …
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