October 30, 2023
Youths with ADHD are at higher risk of suicide, burn injuries, road injuries, and more generally all-cause mortality than normally developing children. Methylphenidate (MPH) is known to be effective in reducing ADHD symptoms. Can it also reduce the risk of all-cause mortality? A team of Taiwanese researchers, collaborating with two British researchers, explored that question by looking at a nationwide population cohort.
Taiwan has a single-payer national health insurance system that includes the entire population (99.6 percent coverage). Using the National Health Insurance Research Database (NHIRD), the team identified over 183,000 youths under 18 with an ADHD diagnosis. Of these, just over 68,000 had been prescribed to MPH. The team matched them with an equal number of ADHD youths who were not prescribed MPH. All records were anonymized and checked against the National Mortality Register.
All-cause mortality was split into two subcategories. Unnatural-cause mortality consisted of homicide, suicide, and motor vehicle fatalities. Natural-cause mortality encompassed all other premature deaths. In the raw data, ADHD youths on MPH had half the all-cause mortality of those not on MPH. Natural-cause mortality was down about 40 percent and unnatural-cause mortality was by almost two-thirds. In the non-MPH group, 32 committed suicide in the follow-up year, versus only a single individual in the MPH group. There were seven homicide victims in the non-MPH group, versus none at all in the MPH group.
These staggering reductions, however, were almost exclusively among males. The team then adjusted for potential confounding variables - gender, age, residence, insurance premium, out-patient visits, and pre-existing diagnoses. In the adjusted model, the risk for all-cause mortality was still reduced - by about 20 percent - for those on MPH and remained statistically significant. Virtually identical reductions were found for males and for children first diagnosed with ADHD between 4 and 7 years old. But all other risk estimates became statistically non-significant, due in large measure to the rarity of mortality events.
The authors concluded, "This is the first study reporting that a longer interval between first ADHD diagnosis and first prescription of MPH is associated with a higher risk of all-cause mortality. In addition, we also found that participants receiving longer-duration MPH treatment had a lower risk of all-cause mortality. ... an implication is that receiving a diagnosis earlier and receiving medication earlier may reduce the risk of later adverse consequences."
They nevertheless cautioned, "although we adjusted for multiple covariant, information lacking in the database precluded the measurement of other possible confounders, such as family history, psychosocial stressors, the effect of behavioral therapy or severity of comorbidities. Therefore, as with all observational data, it is not possible to be conclusive about whether the association with lower mortality is related to an effect of MPH treatment itself or whether other characteristics of the children receiving MPH may account for the lower risk (i.e. confounding by indication).
Finally, although the cohort sizes were large, the number of deaths was small, and this limited statistical power, particularly for the investigation of cause-specific mortality and of subgroup differences. Because of the relatively low number of deaths and limited follow-up duration, longer-term studies with larger samples are warranted ..."
Vincent Chin-HungChen, Hsiang-Lin Chan, Shu-I Wu, Mong-Liang Lu, Michael E. Dewey, Robert Stewart, and Charles Tzu-Chi Lee, "Methylphenidate and mortality in children with the attention-deficit hyperactivity disorder: a population-based cohort study," British Journal of psychiatry (2020), https://doi.org/10.1192/bjp.2020.129.
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Previous studies have examined how stimulant medications affect the brain in controlled settings, but less is known about their impact in real-world conditions, where children may not always take their medication consistently or may combine it with other treatments. A new study leverages data from the Adolescent Brain Cognitive Development (ABCD) study to explore how real-world stimulant use impacts brain connectivity and ADHD symptoms over two years.
Changes in Brain Connectivity Researchers used brain imaging data from the ABCD study to examine the functional connectivity—communication between brain areas—of six regions within the striatum, a brain area involved in motivation and movement control. They focused on how stimulant use influenced connectivity between the striatum and other networks involved in executive functioning and visual-motor control.
The study found that stimulant exposure was linked to reduced connectivity between key striatal areas (such as the caudate and putamen) and large brain networks, including the frontoparietal and visual networks. These changes were more pronounced in children taking stimulants compared to those who were not medicated, as well as compared to typically developing children. Importantly, this reduction in connectivity seemed to regulate certain brain networks that are typically altered in children with ADHD.
Symptom Improvement In addition to brain changes, 14% of children taking stimulants experienced a significant reduction in ADHD symptoms over the two-year period. These children showed the strongest connectivity reductions between the right putamen and the visual network, suggesting that stimulant-induced connectivity changes may contribute to improvements in visual attentional control, which is a common challenge for children with ADHD.
Why This Matters This study is one of the first to examine how stimulant use in real-world conditions affects brain networks in children with ADHD over time. The findings suggest that stimulants may help normalize certain connectivity patterns associated with ADHD, particularly in networks related to attention and control. These insights could help clinicians better understand the potential long-term effects of stimulant treatment and guide personalized approaches to ADHD management.
Conclusion Stimulant medications appear to alter striatal-cortical connectivity in children with ADHD, with some changes linked to symptom improvement. This research highlights the potential for stimulant medications to impact brain networks in ways that support attention and control, highlighting the importance of understanding how real-world medication use influences ADHD treatment outcomes.
The Neuroeconomic Perspective
Neuroeconomics combines neuroscience, psychology, and economics to understand how people make decisions. Neuroeconomic studies suggest that brain regions responsible for evaluating risk and reward, including the prefrontal cortex and dopamine pathways, function differently in individuals with ADHD. These insights are crucial for developing more tailored interventions. For example, understanding how ADHD affects reward processing might inform strategies that help individuals resist impulsive choices or increase motivation for delayed rewards.
Understanding Decision-Making in ADHD
We know that decision-making is a sophisticated process involving various cognitive procedures. It’s not just about choosing between options but also about how to weigh risks, rewards, and potential future outcomes; Attention, motivation, and cognitive control are core to this process. For individuals with ADHD, however, this neural framework is affected by impairments in attention and impulse control, often resulting in “delay discounting”—the tendency to prefer smaller, immediate rewards over larger, delayed ones.
This propensity for impulsive decisions is more than a personal challenge; it has broader societal and economic implications. Previous studies have shown that these tendencies in ADHD can lead to issues in academics, work, finances, and personal relationships, emphasizing the need for targeted support and interventions.
Implications and Future Directions
This review highlights a need for continued research to bridge the gaps in understanding how ADHD-specific cognitive deficits influence decision-making. Viewing ADHD through a neuroeconomic lens clarifies how cognitive and neural differences affect decision-making, often leading to impulsive choices with economic and social impacts. This perspective opens doors to more effective interventions, improving decision-making for individuals with ADHD. Future policies informed by this approach could enhance support and reduce associated societal costs.
Children with ADHD face significant challenges in academic and social settings, often including difficult interactions with teachers. This meta-analysis investigates the quality of student-teacher relationships for children with ADHD, focusing on two key dimensions: closeness and conflict. By synthesizing data from 27 studies encompassing 17,236 participants, the study aims to provide a comprehensive understanding of these dynamics and inform interventions to support both students and teachers.
A systematic review was conducted using databases such as PsycInfo, ERIC, and ProQuest. Researchers identified 47 effect sizes from 27 studies, examining the association between ADHD symptoms and the quality of student-teacher relationships. Relationship quality was assessed through two primary dimensions:
Eight moderator analyses were also performed to explore how factors like grade level, gender, ADHD presentation, and comorbid conditions influenced these relationships.
The findings reveal that children with ADHD symptoms typically experience relationships with teachers characterized by lower levels of closeness and higher levels of conflict. Notably, externalizing behaviors such as hyperactivity and impulsivity are more strongly associated with conflict than inattentive symptoms. Moderator analyses showed that factors like gender, ADHD presentation, and age influence the severity of these relationship dynamics. For instance, younger children and those with hyperactive-impulsive presentations tend to have higher conflict levels with teachers.
Additionally, the research emphasizes the reciprocal nature of these relationships: ADHD symptoms may exacerbate teacher frustration, while negative teacher-student interactions can intensify student behavioral challenges.
Conclusion
This meta-analysis highlights the critical role of student-teacher relationships in the development of children with ADHD. The findings underline the need for targeted interventions that foster positive teacher-student interactions and reduce conflict. Addressing these relationship dynamics could enhance academic performance, social integration, and emotional well-being for children with ADHD. Future research should explore the causal pathways between ADHD symptoms and relationship quality to better inform educational strategies and support systems.
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