The debate so far…

Concerns regarding attention-deficit hyperactivity disorder (ADHD) – commonly defined as a neurodevelopmental condition, and which manifests as impaired attention and/or hyperactivity and impulsivity – are not new. A year ago an article in the British Journal of Psychiatry generated a buzz when it reported ‘extremely concerning’ findings ^{Reference O’Nions, El Baou, John, Lewer, Mandy and McKechnie1} with respect to the life expectancy and mortality of people diagnosed with ADHD. Using UK primary care data, O’Nions and colleagues ^{Reference O’Nions, El Baou, John, Lewer, Mandy and McKechnie1} found that adults with ADHD live significantly shorter lives and are approximately two times more likely to die sooner than those without the illness. Since its publication in January 2025, this article has been mentioned in more than 200 news outlets worldwide and was widely discussed in podcasts, blogs and social media platforms, illustrating that ADHD is on everyone’s mind.

The article by O’Nions et al ^{Reference O’Nions, El Baou, John, Lewer, Mandy and McKechnie1} has also prompted several commentaries, to which the authors have already replied. ^{Reference O’Nions and Stott2} One commentary emphasised that ‘[their] sobering findings demand careful scrutiny’, ^{Reference Ophir3} while others pointed to the role of their research in shaping ‘future advancements in ADHD diagnosis and treatment’. ^{Reference Hasnain, Sulehria and Sethi4} Clearly, the possibility that ADHD might significantly reduce life expectancy is an important issue that warrants closer examination and, when deliberating the risks associated with the condition, the potential role of medication should be carefully considered. Notably, although mentioned in passing, the diagnostic precision of ADHD is not questioned sufficiently by O’Nions and colleagues ^{Reference O’Nions, El Baou, John, Lewer, Mandy and McKechnie1} and this is puzzling, given that any response to medication is invariably contingent on diagnosis.

ADHD medications: help or hindrance?

The shortening of life expectancy suggests perhaps that ADHD treatments, as currently prescribed, are not effective in preventing early death. In other words, although from time to time they might reduce some ADHD symptoms, they are not necessarily disease-modifying per se and, perhaps, having the illness curtails life expectancy. Alternatively, the effect may be compounded because ADHD medications increase the possibility of cardiovascular complications, which carry the risk of sudden death. ^{Reference Ophir3} However, some emerging findings imply the opposite. ^{Reference Vasiliadis, Lunghi, Rahme, Rochette, Gignac and Massamba5,Reference Li, Zhu, Zhang, Kuja-Halkola, D’Onofrio and Brikell6} Specifically, research by Vasiliadis et al ^{Reference Vasiliadis, Lunghi, Rahme, Rochette, Gignac and Massamba5} suggests a ‘protective effect’ of stimulant ADHD treatment against the risk of all-cause mortality, while findings by Li et al ^{Reference Li, Zhu, Zhang, Kuja-Halkola, D’Onofrio and Brikell6} indicate that initiating ADHD stimulant and non-stimulant medications within 3 months of diagnosis potentially lowers both all-cause mortality and that brought about by unnatural causes (e.g. suicide, accidents). Together, the results of these two studies, conducted in different populations (Canadian and Swedish, respectively), suggest that medications might in fact prevent adults with ADHD from dying early – thus favouring their use.

In the reply to commentaries, O’Nions et al emphasise that ‘[their] aim was to provide an estimate of the overall difference in life expectancy experienced by people with diagnosed ADHD rather than to explore underlying mechanisms’, adding that ‘[these] important mechanisms […] could be examined in future work’. ^{Reference O’Nions and Stott2} We wholeheartedly agree that mechanisms are key to gaining a better understanding and improving clinical management and, in this context, we pose these fundamental questions of considerable importance: are ADHD medications effective in treating the illness, and are they even necessary? A recent publication in Lancet Psychiatry ^{Reference Ostinelli, Schulze, Zangani, Farhat, Tomlinson and Del Giovane7} suggests that the benefits of medications used to treat ICD- and DSM-diagnosed ADHD are substantially limited. Specifically, the network meta-analysis (NMA) by Ostinelli et al ^{Reference Ostinelli, Schulze, Zangani, Farhat, Tomlinson and Del Giovane7} revealed that only stimulants and atomoxetine are effective in reducing ADHD core diagnostic symptoms (i.e. defined as inattention, hyperactivity and impulsivity), and that these effects have been proven only in the short term. When considering the long-term efficacy of ADHD medications, the ratio of any benefits versus harms remains unknown due to insufficient data. Furthermore, the NMA showed that stimulants had similar acceptability to placebo, that atomoxetine was less acceptable than placebo, that atomoxetine, modafinil, guanfacine and stimulants were less tolerable than placebo and that no medications improved the overall quality of life for patients. ^{Reference Ostinelli, Schulze, Zangani, Farhat, Tomlinson and Del Giovane7} Furthermore, a recent umbrella review by Gosling et al ^{Reference Gosling, Garcia-Argibay, De Prisco, Arrondo, Ayrolles and Antoun8} found that, although there was some evidence to support the short-term use of medications and non-drug approaches, there was ‘no high certainty, long term evidence […] for any intervention’. Hence, the results of that NMA ^{Reference Ostinelli, Schulze, Zangani, Farhat, Tomlinson and Del Giovane7} and the umbrella review ^{Reference Gosling, Garcia-Argibay, De Prisco, Arrondo, Ayrolles and Antoun8} jointly cast a different light on the effects of ADHD medications as compared with the two studies we discussed earlier. ^{Reference Vasiliadis, Lunghi, Rahme, Rochette, Gignac and Massamba5,Reference Li, Zhu, Zhang, Kuja-Halkola, D’Onofrio and Brikell6} Therefore we remain in a quandary, and the apparently contradictory views on the mortality risk associated with ADHD medications exacerbate our dilemma further.

The opposing perspectives on ADHD pharmacological treatments are also presented in some of the commentaries. For instance, while Ophir et al ^{Reference Ophir3} emphasise the significant risk of suicide and cardiovascular diseases associated with the use of ADHD medications, Hasnain et al ^{Reference Hasnain, Sulehria and Sethi4} point to ‘the rectifying impact of ADHD pharmacotherapy on the severity of the symptoms‘ by drawing on data that show an association between the use of ADHD medications and a decrease in mortality and lowering of suicide risk.

Therefore, in sum, we are faced with quite disparate views informed by research suggesting that, first, adults with ADHD die sooner than they should but that, second, ADHD medications, which are often first-line treatment, reduce this mortality risk even though these same medications appear to have only short-term benefits and might confer long-term risks, some of which are life-threatening. Thus, it is fair to say that it is unclear what effect medications have when prescribed in the treatment of ADHD and, furthermore, what role they should play.

We believe that the reason for our confusion is not solely the paucity of research into the effects of ADHD medications and the likelihood that these vary depending on the agent prescribed, but that there is a more fundamental problem: the research on ADHD is based on an invalid and unreliable diagnosis. In our view, ADHD diagnostic criteria from widely used taxonomies suffer from imprecision. This is because, not only do the criteria rely solely on clinical observations but they also lack any ordering or hierarchy within the symptoms themselves to indicate which are the central characteristics or features of the illness, or any that are potentially pathognomic.

Consequently, ADHD is at high risk of being either missed or misdiagnosed, with many individuals possibly receiving an ill-fitting diagnosis and, as a consequence, being subjected to unnecessary treatment. Recently this practice has been featured in mainstream media. An account published in The Australian Financial Review ^{Reference Smith9} both underscores the laxity with which a diagnosis of ADHD is sometimes made and, perhaps, explains the confusion surrounding the effects of ADHD medications (see Box 1). An added complication is that of circular diagnostic reasoning, in which a transient change in response to (often stimulant-based) treatment is used to confirm a diagnostic impression. Then, the illness is managed with this same treatment because it is the indicated therapeutic agent – based, again, on the same response. This unreliable method considerably increases the risk of unreliable diagnosis and inappropriate treatment, especially because, like all treatments, ADHD medications are subject to adverse effects, and stimulants are mood-modifying and increase energy and drive – potentially masking or moderating the signals of alternative diagnoses.

Returning to the question of whether ADHD impacts life expectancy – if this is indeed the case, then what role, if any, do ADHD medications play in this potential link? Clearly, if the diagnosis itself is suspect then anything that follows in the management pathway, such as its treatment, is equally suspect. Research examining the effects of medications relies on having well-defined patient populations. Similarly, epidemiological studies that endeavour to map the prevalence, causes, trajectories and outcomes of an illness rely on being able to accurately define the illness and identify cases. Put another way, if the diagnosis is imprecise, then the scientific outputs and conclusions that are derived from this diagnosis are equally likely to miss the mark.

The lack of ADHD diagnostic fidelity necessarily results in a heterogenous population of patients, from which it is impossible to reliably distinguish those who genuinely have ADHD from those who do not. Therefore, the aforementioned studies, and their at-times contradictory findings, are also fundamentally impacted by this imperfect distinction. Hence, we cannot have complete confidence that their findings accurately capture ‘true’ ADHD, nor that they are fully incorrect. For example, can we be certain that mortality rates were associated only with the cases of true ADHD in the study by Vasiliadis et al? ^{Reference Vasiliadis, Lunghi, Rahme, Rochette, Gignac and Massamba5} In that study, the sample included those who ‘either had a physician claim or hospital diagnosis of ADHD […] or had filled a prescription for an ADHD medication’. Apart from the likelihood that a proportion of this group received an ADHD diagnosis incorrectly, another subgroup was diagnosed based solely on being prescribed an ADHD drug. This is an example of diagnosing ADHD based on assuming a patient’s positive response to medication and, while Vasiliadis et al ^{Reference Vasiliadis, Lunghi, Rahme, Rochette, Gignac and Massamba5} recognised this as a limitation of their study, ensuring that the results of their research remain the same if only those with taxonomy-based diagnosis were considered, we are puzzled as to why this strategy has been implemented and is still being used and accepted in psychiatric practice.

Suggested course of action

Until now, we have pointed out the confusion regarding the role of medications in the treatment of ADHD and reduced life expectancy of adults diagnosed with this disorder. Most importantly, however, we have been critical about the fundamental problem that fuels this confusion: the flawed ADHD diagnostic criteria. Our goal, however, is not solely to bring to the fore what needs to be changed, but also to offer a potential way forward as to how we can change it. Therefore, we propose that the first and most crucial step towards achieving a better understanding of the true nature of ADHD as a clinical entity – and, most importantly, a better outcome for patients – is not simply to refine but to redefine the criteria upon which a diagnosis is made.

Broadly speaking, to establish validity and reliability of the ADHD diagnosis we should perhaps implement scientific methods that entail the close observation of symptoms in different settings, on which basis we form predictions that can subsequently be verified by empirical research. We envisage this to be an iterative process, involving collaboration among researchers, clinicians and patients that continuously informs the diagnosis and increases its precision over time. In practice, this should lead to greater homogeneity of the clinical picture of ADHD that may then allow progressively more reliable differentiation of genuine ADHD cases from those who do not have the illness, and from other disorders. The specificity of the ADHD population is irrefutably essential for reliable research into the potential biological markers of the disorder, its trajectories and the long-term effects of pharmacological and non-pharmacological treatments. Without such diagnostic specificity and therapeutic precision, we cannot advance our understanding of the condition and improve outcomes such as life expectancy.

Although we recognise the complexity of ADHD and the difficulties of capturing its true nature, there are some critical questions such as (a) whether a person has an illness, and if so; (b) how it is impacting their functioning; (c) whether it can be managed with treatment; and, furthermore, (d) what type of intervention is most effective, especially in the long term. Meaningful answers to these questions will materialise only if the condition itself is stringently defined. Hence, we argue that this is where we should direct our attention to begin with.