Adults with high levels of attention-deficit hyperactivity disorder (ADHD) symptoms are more likely to experience anxiety and depression than adults with high levels of autistic traits, according to new research led by psychologists at the University of Bath in the UK.

This study is the first to show that ADHD predicts poor mental health outcomes in adults more than other neurodevelopmental conditions, like autism.

Until now, there has been a dearth of information on the effects of ADHD on poor mental health, with far more research focusing on the impact of autism on depression, anxiety and quality of life. As a result, people with ADHD often struggle to access the clinical care they need to cope with their symptoms.

The study’s authors hope their findings will trigger new research into ADHD and ultimately improve the mental health outcomes for people with the condition. ADHD is a neurodevelopmental condition characterised by inattention and/or hyperactivity and impulsivity. The condition is estimated to affect between 3% and 9% of the population.

Blue Monday

Speaking on Blue Monday (January 16) – the third Monday of January, described by some as the gloomiest day of the year – lead researcher, Luca Hargitai, said: “Scientists have long known that autism is linked to anxiety and depression, but ADHD has been somewhat neglected.

“Researchers have also struggled to statistically separate the importance of ADHD and autism for mental health outcomes because of how frequently they occur together.”

Ms Hargitai, a PhD Researcher at Bath, added: “Our aim was to precisely measure how strongly ADHD personality traits were linked to poor mental health while statistically accounting for autistic traits.”

The new research – a collaborative effort between the Universities of Bath, Bristol and Cardiff, and King’s College London – is published this week in the prestigious journal Scientific Reports. It comes in the same month that two British TV personalities – Johnny Vegas and Sue Perkins – have opened up about their recent diagnoses of ADHD.

“The condition affects many people – both children and adults – and the fact that more people are willing to talk about it is to be welcomed,” said Ms Hargitai. “The hope is that with greater awareness will come more research in this area and better resources to support individuals in better managing their mental health.”

Overly active, as though driven by a motor

The study used a large, nationally representative sample of adults from the UK population. All participants completed gold standard questionnaires – one on autistic traits, the other on ADHD traits – responding to statements such as “I frequently get strongly absorbed in one thing” and “How often do you feel overly active and compelled to do things like a motor drove you?”

The researchers found that ADHD traits were highly predictive of the severity of anxiety and depression symptoms: the higher the levels of ADHD traits, the more likely a person is to experience severe mental health symptoms. Through innovative analytical techniques, the study authors further confirmed that having more of an ADHD personality was more strongly linked to anxiety and depression than autistic traits.

These results were replicated in computerised simulations with a 100% ‘reproducibility rate’. This showed, with great confidence, that ADHD traits are almost certainly linked to more severe anxiety and depression symptoms in adults than autistic traits.

Shifting the focus of research and clinical practice

Ms Hargitai said: “Our findings suggest that research and clinical practice must shift some of the focus from autism to ADHD. This may help to identify those most at risk of anxiety and depression so that preventative measures – such as supporting children and adults with the management of their ADHD symptoms – can be put in place earlier to have a greater impact on improving people’s wellbeing.”

According to Dr Punit Shah, senior author and associate professor of Psychology at Bath, another important aspect of the new study is that it advances scientific understanding of neurodevelopmental conditions.

“By addressing the shortcomings of previous research, our work provides fresh information about the complex links between neurodiversity and mental health in adults – an often overlooked area.

“Further research is now needed to delve deeper into understanding exactly why ADHD is linked to poor mental health, particularly in the mental processes that might drive people with ADHD traits to engage in anxious and depressive thinking.

“Currently, funding for ADHD research – particularly psychological research – is lacking. This is significantly pronounced compared to the relatively high funds directed at autism.

“As the evidence becomes clear that ADHD isn’t just a childhood condition but persists throughout life, we must adjust our research agendas to understand ADHD in adulthood better.”

Commenting on the new findings, Dr Tony Floyd, CEO of ADHD Foundation, The Neurodiversity Foundation, said: “This research demonstrates clear evidence of the increased risks of mental health comorbidities associated with adult ADHD. This is a step towards recognising the broader impact of unmanaged and untreated ADHD. We hope this research will lead to more commissioned research in this area. We also hope it will result in changes to the design and delivery of health services.

“The cost implications to the NHS of leaving ADHD untreated, and the need to better train health practitioners in primary and secondary care, are now more apparent. And of course, there are other costs too that need to be considered – to the health of UK citizens with ADHD and to their family life, employability and economic well-being. These costs are often hidden, but they are considerable.

“This research from Bath University will add to the growing national debate and the business case for a national review of health services for ADHD across a person’s lifespan.”

Can the eyes help understand the brain? CREDIT Per Jensen

It’s often said that ‘the eyes tell it all’, but no matter what their outward expression, the eyes may also be able to signal neurodevelopmental conditions such as autism and ADHD according to new research from Flinders University and the University of South Australia.

In the first study of its kind, researchers found that recordings from the retina could identify distinct signals for both Attention Deficit Hyperactivity Disorder (ADHD) and Autism ) providing a potential biomarker for each condition.

Using the ‘electroretinogram’ (ERG) – a diagnostic test that measures the electrical activity of the retina in response to a light stimulus – researchers found that children with ADHD showed higher overall ERG energy, whereas autistic children showed less ERG energy.

Research optometrist at Flinders University, Dr Paul Constable, says the preliminary findings indicate promising results for improved diagnoses and treatments in the future.

“Autism and ADHD are the most common neurodevelopmental disorders diagnosed in childhood. But as they often share similar traits, making diagnoses for both conditions can be lengthy and complicated,” Dr Constable says.

“Our research aims to improve this. By exploring how signals in the retina react to light stimuli, we hope to develop more accurate and earlier diagnoses for different neurodevelopmental conditions.

“Retinal signals have specific nerves that generate them, so if we can identify these differences and localise them to specific pathways that use different chemical signals that are also used in the brain, then we can show distinct differences for children with ADHD and autism and potentially other neurodevelopmental conditions.”

“This study delivers preliminary evidence for neurophysiological changes that not only differentiate both ADHD and ASD from typically developing children, but also evidence that they can be distinguished from each other based on ERG characteristics.”

According to the World Health Organization, one in 100 children has autism, with 5-8 per cent of children diagnosed with ADHD.

Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental condition characterised by being overly active, struggling to pay attention, and difficulty controlling impulsive behaviours. Autism is also a neurodevelopmental condition where children behave, communicate, interact, and learn in ways that are different from most other people.

Co-researcher and expert in human and artificial cognition at the University of South Australia, Dr Fernando Marmolejo-Ramos, says the research has the potential to extend across other neurological conditions.

“Ultimately, we’re looking at how the eyes can help us understand the brain,” Dr Marmolejo-Ramos says.

“While further research is needed to establish abnormalities in retinal signals that are specific to these and other neurodevelopmental disorders, what we’ve observed so far shows that we are on the precipice of something amazing.

“It is truly a case of watching this space; as it happens, the eyes could reveal all.”

Research led by King’s College London and South London and Maudsley NHS Foundation Trust has analysed factors associated with self-harm in over 111,000 adolescents aged 11-17 years old.

Published in BMC Medicine the study found that the risk for self-harm presenting to hospital emergency departments was nearly three times higher for boys with autism spectrum disorder (ASD) compared to boys without ASD. 

Attention Deficit Hyperactivity Disorder (ADHD) was a strong predictor of self-harm for both boys and girls with approximately a four-fold increased risk for self-harm amongst those with ADHD. 

Absence from school was also associated with increased risk for self- harm: for those young people with less than 80 per cent attendance the risk of hurting themselves was three times greater.

Part-funded by the National Institute for Health and Care Research (NIHR) Maudsley Biomedical Research Centre and the Wellcome Trust, this is the first long-term investigation of adolescent self-harm and ASD using linked school and hospital data in England. The research provides valuable insight into those groups most at risk, representing an important step in developing preventative strategies for self-harm.  

Dr Johnny Downs, Consultant Child & Adolescent Psychiatrist at South London and Maudsley and NIHR Clinician Scientist at the Department of Child & Adolescent Psychiatry, King’s College London and senior author on the paper said: “By linking these large-scale datasets, we have been able to understand which groups of young people may be most vulnerable to self-harming. Crucially we are using local data, so it has direct implications for the NHS Trust where I work and can improve our targeting of mental health interventions within South London schools. Another important aspect of this study is that any region in England could use the same approach, as the school and hospital data already exist and can be linked.” 

Self-harm is common in adolescents and research suggests about 1 in 5 self-harm. Around 12 per cent of episodes of adolescent self-harm are seen at emergency departments and these are the young people most likely to be at risk of suicide.

Researchers connected data on hospital attendance for self-harm to educational data. This enabled examination of education factors such as school attendance, special educational needs and free school meal status as well as data on mental health service use. The study assessed data from 113,286 young people from four boroughs in South London collected between 2009-2013.

By analysing data from the National Pupil Database on whether children had been assigned special educational needs for ASD, the study showed that boys with ASD were at greater risk of self-harm than boys without ASD. This pattern was not observed amongst girls with ASD but in general the risk of self-harm was higher in girls than in boys (1.5% compared to 0.3% in boys).

Emily Simonoff, Professor of Child & Adolescent Psychiatry at King’s College London, and Theme Lead for Child Mental and Neurodevelopmental Disorders in the NIHR Maudsley Biomedical Research Centre who is a co-author on the paper said: “We know that autistic adults have higher rates of premature death, including increased rates of suicide.  Self-harming behaviours, like those explored in the present study, may be the precursor to more serious suicide attempts, so early identification and proactive intervention when self-harm first appears is very important. Autistic people often have more difficulty regulating their emotions, which can contribute to high levels of distress and, because of the communication impairments experienced by many autistic people, professionals may not appreciate the level of distress they are experiencing and the seriousness of these behaviours.”

The study also found adolescents who had attended mental health services for ADHD were at four times the risk of self-harm than those who had not attended services for ADHD. School exclusion and absence were also identified as risk factors.

Joint first author Dr Emily Widnall who conducted the research while at King’s and is now Senior Research Associate in Public Health at University of Bristol said: “Our research has shown that adolescents who spent time away from school, either through exclusion or absence, have an increased risk for self-harm compared to young people who are in school most of the time. Linking educational data to mental health data has an important role to play in answering public health research questions in child and adolescent mental health and can help identify where more support is needed within schools.”

The study also revealed findings that may need further research to unpick the possible underlying mechanisms. For example, the finding that girls with ASD were at no higher risk to self-harm than those without ASD could be explained by underdiagnosis of ASD in girls.

The study also found that those who spoke English as a second language were at a lower risk to self-harm than those with English as their mother tongue.

“Taken at face value the results suggest young people who are resident in London but non-native English speakers, have less mental health difficulties,” commented Dr Downs.  “But there could be other influences at work which could mean that these young people are self-harming and not presenting to services or are expressing their distress through other means such as misusing substances.”