Doctors urgently need better international guidance on treating attention deficit hyperactivity disorder (ADHD) in the over 50s, conclude world-leading experts reviewing current research on this increasing issue globally.

Published in the peer-reviewed journal Expert Review of Neurotherapeutics, the team's findings highlight a 'striking' gap in knowledge about older people as existing guidelines focus on children and young adults.

"Our analysis concludes that better approaches are urgently required to screen and diagnose people aged from around age 50 to 55," says lead author Dr Maja Dobrosavljevic from the University of Orebro, in Sweden.

"As we gain deeper insights into the challenges faced by older adults living with ADHD, a comprehensive and tailored approach is crucial for their well-being.

"We therefore urge the medical community, researchers, and policymakers to collaborate in refining diagnostic criteria, treatment guidelines, and research initiatives that are inclusive of all age groups affected by ADHD."

Estimated to affect around 2.5% of adults, ADHD runs in families.

Symptoms include being impulsive, hyperactive, and having poor focus, attention, and organizational skills.

The neurodevelopmental disorder can persist throughout life and have a negative impact on education, job prospects and social interaction. Stimulants such as methylphenidate are the most commonly used medication for ADHD.

The team of authors includes Chair of the European ADHD Guidelines Group Samuele Cortese, who is a Professor of Child and Adolescent Psychiatry at the University of Southampton, and Henrik Larsson, a Professor of psychiatric epidemiology at Orebro University.

They reviewed almost 100 studies. Of these, 44 were papers on the prevalence, health outcomes, diagnosis, and treatment efficacy/safety, as well as clinical guidelines/consensus statements providing recommendations on clinical diagnosis and treatment of ADHD in older adults.

The team then assessed the current diagnostic criteria according to the Diagnostic and Statistical Manual of Mental Disorders (DSM), and the World Health Organisation's International Classification of Diseases (ICD). Other aspects were also evaluated such as how useful current criteria are for diagnosing older adults.

"Our results show no studies have observed people over a long time period into older age. Research has instead focused on retrospective assessment of childhood symptoms, and this can be unreliable because of age-related memory issues," says Professor Larsson, whose expertise lie in how genes and environment influence mental health problems across the life span.

"Essentially, this means that more trials are needed into the safety and efficacy of current ADHD medication, including the maximum recommended doses, used to treat this age group – who are at increased risk of other health conditions such as heart problems."

Doctors should be assessing the physical health of an older person with ADHD before prescribing drug treatment.

Diagnostic criteria have shifted towards a 'wider inclusion' of adults who previously would have remained undiagnosed.

Yet, still, there is no specific consideration of how ADHD presents in older adults.

Another issue is that screening tools validated for ADHD in older adults are not specific enough to recognize the condition in the over 50s. Only those with the most severe ADHD would be picked up."

Henrik Larsson, Professor of Psychiatric Epidemiology, Orebro University

The team's analysis also adds further weight to conclusions that ADHD is linked with mental health issues, increased death rates, and illness such as cardiovascular disease and dementia.

However, diagnosis remains an issue for this age group.

The research concludes that one of the main challenges for clinicians is that some medical conditions among older adults have similar clinical presentations as ADHD such as menopause-related memory decline.

On this basis, the researchers recommend that doctors take into account distinctive clues to distinguish ADHD from age-related mild cognitive impairment (MCI). People with ADHD typically report childhood symptoms whereas MCI has a more abrupt onset, they point out.

The authors do concede that future editions of the DSM and ICD are expected to address current gaps in the definition of ADHD for older adults, and that more data will become available.

They suggest that classification for older adults should include diagnoses that differentiate between ADHD and conditions with similar symptoms.