Terry Maguire examines the increasing diagnoses of ADHD and wonders if the medical world is taking the right approach
Methylphenidate shortage
I am, like most pharmacists, getting around four calls a week looking for methylphenidate. There has been an irritating shortage of methylphenidate medicines recently, mostly for the slow-release formulations, as manufacturers struggle to satisfy demand. Those contacting me are often adult patients, as many people are now being diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) in adulthood, whereas in the past, the condition was mainly diagnosed in children.
The NHS waiting list for an ADHD referral is something in the region of seven years, so it is not surprising that many who think they might have the condition are seeking an assessment from private practitioners. However, this can then create conflict with GPs unwilling to accept a diagnosis from a private practice if they are being asked to prescribe controlled drugs with some potentially significant side-effects. One GP told me he hasn’t found a private practice that did not make a confirmed diagnosis.
Since 2015, the prevalence of ADHD in the UK has tripled. Such a large increase begs the question, why? One thing you should never do is suggest that ADHD is a made-up condition, as there is little doubt people experience symptoms that are sufficiently severe to impair personal development and normal social functioning — but do these symptoms always justify an ADHD diagnosis? There is also a view that an ADHD diagnosis provides a label, a type of ‘get-out-of-jail-free card’ that closes off individuals from the idea of change — the simpler solution — when change might be what is needed.
The anxious generation
Technology is being blamed, and certainly might be an explanation in children and young adults who live online, bombarded with constant stimulation. Jonathan Haidt in his recent bestseller The Anxious Generation references studies that show young adults who are constantly stimulated by social media are more likely to have a diagnosis of ADHD.
Attention is a key element of a healthy pre-frontal cortex, the last part of the brain to develop. Attention is fragmented by constantly altering stimuli and the child becomes unable to make and execute plans. It is the curtailing of social media, especially smartphones, that is needed, according to Haidt, not daily doses of stimulant drugs. Indeed, Australia has recently taken the step of becoming the world’s first country to ban social media for the under-16s, while many UK schools have sought to ban smartphones, yet it’s too early to say if or how this will impact on the prevalence of ADHD.
Diagnosis
The Diagnostic and Statistical Manual of Mental Disorders, fifth edition, or the DSM-5, is the definitive guide on mental disorders for healthcare professionals in the US and much of the world. Since the 1980s, it has provided clinicians with diagnostic criteria for ADHD, but it was only in 2013 that it updated its definition of ADHD to include adult ADHD.
Before the mid-1980s, ADHD didn’t really exist, certainly as a diagnosis, but children with challenging behaviours did and, indeed, in those years I had one of them myself. I did often look at this tender child and wonder what made him do the things he did. It never entered my head that he could be suffering from a mental health condition, let alone want to seek out medicines that might ‘normalise’ his behaviour. Thirty years on, I don’t feel any guilt that we were negligent or failed him. On the contrary, I am proud to say he has grown into a totally responsible adult, has married, taken on a mortgage, and holds down an impressive job in IT. Had we presented him to a competent psychologist or psychiatrist, he might well have been given an ADHD diagnosis and spent his childhood on Ritalin.
The symptoms currently listed are inattention, poor planning, hyperactivity, short attention span, and impulsivity. These must be pervasive, which means the patient must have these in all settings — at home, at school, at play. My son would have ticked all these boxes. But should his behaviour have been pathologised? Or was he just an outlier in the behaviours that make up the human condition?
In our capitalist society, there is always a tendency to find new markets, and ADHD has offered up a goldmine for private practitioners. Also, and interestingly, there has never been a stigma associated with an ADHD diagnosis the way there can be with other mental health conditions. Indeed, many social influencers and celebrities are happy to wear the label. Perhaps it might explain some of the things they do.
We have three things converging: First, a broader and looser diagnosis; second, diagnosis creep — doctors find it easier to diagnose; and third, medicines to treat the condition.
A number of high-profile doctors have expressed concern about the surge in ADHD diagnoses. These include Prof Simon Wessely, former President of the Royal College of Psychiatrists, Dr Iona Heath, former President of the Royal College of GPs, and Dr Max Pemberton, psychiatrist and medical writer. They point out that it is a doctor’s responsibility to resist the drive to over-diagnosis and over-treat patients. It is suggested other health professionals remain quiet, fearful of a backlash from social media.
Anyone can complete an ADHD questionnaire online. This I have done. It asks ‘Am I easily distracted?’ Well, yes. ‘Am I often late for meeting appointments?’ ‘Do I regularly forget appointments?’ Yes, yes, and yes. By the end of this 20-minute questionnaire, I was getting an appointment and being reassured that my problems would soon be over. I challenge any pharmacist working as we do in daily chaos to successfully avoid an ADHD diagnosis from this questionnaire.
The medicines
With a diagnosis comes the prescription. We don’t see atomoxetine, clonidine, or guanfacine prescribed so much, as they are non-stimulant and therefore don’t seem to work as well. The latter two are pharmacologically very similar, their main mechanism of action is an agonistic effect at alpha-2 adrenergic receptors throughout the brain. In the brain stem, alpha-2 agonists lead to a reduction in peripheral vascular resistance and consequently lower blood pressure. This has been the traditional of alpha-2 agonists and a main cause of side-effects when used in children.
The mainstay of treatment is the psychostimulants — amphetamines and methylphenidate. Stimulant actions include the inhibition of dopamine and noradrenaline transporters at the synapses increasing the concentration of these neurotransmitters. By enhancing the impact of dopamine and noradrenaline, psychostimulants increase the efficiency of prefrontal cortex activity and optimise executive and attentional function in patients suffering from ADHD. However, the evidence on benefits and harms is, to say the least, uncertain.
In one meta-analysis, out of 212 trials assessed, 191were deemed to be at high risk of bias mainly due to the difficulty blinding the medicines — you can’t get a placebo medicine that gives the same effects.
Methylphenidate compared to placebo may improve teacher?rated ADHD symptoms on the ADHD Rating Scale (ADHD?RS), a scale that is highly subjective and therefore prone to significant reporting bias. The minimal clinically relevant difference is considered to be a change of 6.6 points on the ADHD?RS, and the studies just about get methylphenidate across the line compared to placebo. Oh, and did I mention that most of the studies were sponsored by the drug industry.
Methylphenidate may be associated with an increased risk of adverse events considered non?serious, such as sleep problems and decreased appetite. However, the certainty of the evidence for all outcomes is very low and therefore the true magnitude of effects remains unclear.
Due to the frequency of non?serious adverse events associated with methylphenidate, the blinding of participants and outcome assessors is particularly challenging. To accommodate this challenge, an active placebo should be sought and used. It may be difficult to find such a drug, but identifying a substance that could mimic the easily recognised adverse effects of methylphenidate would avert the unblinding that biases current randomised controlled trials. We are therefore told there is a need for further studies.
Other therapy options
Talking therapy has been shown to be as effective as medication in improving ADHD symptoms and overall functioning levels. However, the NHS currently has less talking therapy options than the medicines.
Some studies have shown that fish oils are helpful. Moreover, they are safe and well-tolerated. However, the results of these studies have been mixed — some children get better, others get worse. Omega-3 fatty acids, such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are important for our brain, body, immune system, and heart. We can only get them from food such as oily fish, spinach, and nuts.
Previous studies have found that children with ADHD eat less omega-3-containing food and have less omega-3 so they are also more likely to show symptoms indicating a lack of omega-3, such as eczema, brittle nails, and dry and scaly skin.
The commercial success of the ADHD business will grow, and already we are seeing new molecules being investigated for use in this patient cohort. These include cannabis (delta-9-tetrahydrocannabinol plus cannabidiol), memantine, oxytocin, tolcapone, and vortioxetine.
Do we need to rethink?
A practising social worker with 35 years of experience in children and adolescent services has recently commented that he, too, is concerned by the surge in diagnoses. He points out that the vast majority of children in care come from chaotic households and these children were much more likely to be diagnosed and medicated.
He did not find the medicines led to much improvement, but he did find improvement with challenging behaviours when carers were able to establish set routines, improve nutrition, and significantly reduce time on electronic devices. Yes, but that requires support, which is also in short supply.
Terry Maguire owns two pharmacies in Belfast. He is an honorary senior lecturer at the School of Pharmacy, Queen’s University Belfast. His research interests include the contribution of community pharmacy to improving public health.
