Combined stimulant and antipsychotic treatment in adolescents with attention-deficit/hyperactivity disorder: a cross-sectional observational structural MRI study

Neuroprotection in late life attention-deficit/hyperactivity disorder: A review of pharmacotherapy and phenotype across the lifespan

For decades, psychostimulants have been the gold standard pharmaceutical treatment for attention-deficit/hyperactivity disorder (ADHD). In the United States, an astounding 9% of all boys and 4% of girls will be prescribed stimulant drugs at some point during their childhood. Recent meta-analyses have revealed that individuals with ADHD have reduced brain volume loss later in life (>60 y.o.) compared to the normal aging brain, which suggests that either ADHD or its treatment may be neuroprotective. Crucially, these neuroprotective effects were significant in brain regions (e.g., hippocampus, amygdala) where severe volume loss is linked to cognitive impairment and Alzheimer's disease. Historically, the ADHD diagnosis and its pharmacotherapy came about nearly simultaneously, making it difficult to evaluate their effects in isolation. Certain evidence suggests that psychostimulants may normalize structural brain changes typically observed in the ADHD brain. If ADHD itself is neuroprotective, perhaps exercising the brain, then psychostimulants may not be recommended across the lifespan. Alternatively, if stimulant drugs are neuroprotective, then this class of medications may warrant further investigation for their therapeutic effects. Here, we take a bottom-up holistic approach to review the psychopharmacology of ADHD in the context of recent models of attention. We suggest that future studies are greatly needed to better appreciate the interactions amongst an ADHD diagnosis, stimulant treatment across the lifespan, and structure-function alterations in the aging brain.

Cumulative exposure to ADHD medication is inversely related to hippocampus subregional volume in children

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Cumulative exposure to ADHD medication characterized as the product of lifetime duration and dose.

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Medication effects investigated on 51 subregional volumes.

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Smaller hippocampus CA1 volumes associated with higher medication exposure.

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Effects remained when correcting for age and ADHD symptom severity.

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No global effects of medication on cortical thickness or surface area detected.

Background

Although there is some evidence for a normalization of brain structure following exposure to ADHD medication, literature on the effects of duration and dose of continued use on the brain is scarce. Here, we investigated the association between cumulative exposure to medication (range 1 week to 4.69 years) and cortical structures and subcortical volumes in a clinical sample of children with ADHD taking medication (n = 109). To the best of our knowledge, this is the first structural MRI study investigating the effects of cumulative exposure to medication on subregional volumes in children treated for ADHD.

Methods

Cumulative exposure to ADHD medication (CEM) was defined as the product of duration on medication (days) and dose (mg/day), yielding the area under the curve (total mg). Cortical thickness and surface area measurements (CIVET-1.1.12), and subcortical volumes in 51 regions (MAGeT-Brain) were analyzed using general linear modelling.

Results

Significant effects of CEM were found in two subregions of the left hippocampus, the CA1 (df = 95; q = 0.003) and the strata radiatum/lacunosum/moleculare (df = 95; q = 0.003). Specifically, higher CEM was associated with smaller volumes within these subregions. No effects of medication exposure were detected on cortical thickness or surface area.

Conclusions

Although this study is cross-sectional, the results found within this sample of children show that prolonged ADHD medication use at higher doses is significantly associated with smaller hippocampus volumes in specific subregions. More research is required to determine whether these results are reproduced in other samples of children of ADHD, and further, whether these are beneficial or off-target effects of the medication.

Suicidal and non-suicidal self-injurious behaviour in patients with bipolar disorder and comorbid attention deficit hyperactivity disorder after initiation of central stimulant treatment: a mirror-image study based on the LiSIE retrospective cohort

BACKGROUND

Currently, our understanding regarding treatment of adult attention deficit hyperactivity disorder (ADHD) co-occurring with bipolar disorder (BD) remains limited. The aim of this study was to evaluate the impact of central stimulant (CS) treatment on suicidal and non-suicidal self-injurious behaviour in patients with a pre-existing diagnosis of BD or schizoaffective disorder (SZD). Specifically, we tested the hypothesis that CS treatment significantly decreased the number of suicide attempts and non-suicidal self-injury events.

METHODS

A mirror-image study in patients with a dual diagnosis of BD or SZD and ADHD, comparing suicide attempts and non-suicidal self-injury events within 6 months and 2 years before and after CS initiation. This study was part of a retrospective cohort study (LiSIE) into effects and side-effects of lithium for maintenance treatment of BD as compared with other mood stabilisers.

RESULTS

Of 1564 eligible patients, 206 patients met the inclusion criteria. Within the 6 months after CS initiation, suicide attempts and non-suicidal self-injury events decreased significantly, both in terms of numbers of patients having such events (p = 0.013) and numbers of events experienced (p = 0.004). These effects were preserved 2 years after CS initiation.

CONCLUSIONS

CS treatment may reduce the risk of suicide attempts and non-suicidal self-injury events in patients with a dual diagnosis of BD or SZD and ADHD. Based on our findings, clinicians should not withhold CS treatment from patients with concomitant ADHD for fear of deterioration of the underlying BD. However, to minimise the risk of manic episodes concomitant mood stabiliser treatment and close monitoring remains warranted.

The Ethics of Neuroenhancement

According to several recent studies, a big chunk of college students in North America and Europe uses so called ‘smart drugs' to enhance their cognitive capacities aiming at improving their academic performance. With these practices, there comes a certain moral unease. This unease is shared by many, yet it is difficult to pinpoint and in need of justification. Other than simply pointing to the medical risks coming along with using non-prescribed medication, the salient moral question is whether these practices are troubling in and of themselves. In due consideration of empirical insights into the concrete effects of smart drugs on brain and behavior, our attempt is to articulate wherein this moral unease consists and to argue for why the authors believe cognitive enhancement to be morally objectionable. The authors will contend that the moral problem with these practices lies less in the end it seeks, than in the underlying human disposition it expresses and promotes. Some might ask, what is wrong with molding our cognitive capacities to achieve excellence, get a competitive edge, or, as the whim takes us? In all of these occasions, the usage of smart drugs serves a certain goal, a telos. The goal is, broadly speaking, this: outsmarting opponents in an arms race for limited resources and thereby yielding a competitive edge. In plain words: competition is valued higher than cooperation or solidarity. What is wrong with striving for this goal? The authors submit that the question whether people really want to live in a society that promotes the mentality ‘individual competition over societal cooperation' deserves serious consideration. In developing their answer, the authors draw on an ‘Ethics of Constraint' framework, arguing that widespread off-label use of smart drugs bears the risk of negative neural/behavioral consequences for the individual that might, in the long run, be accompanied by changing social value orientations for the worse.