The number of cases of attention deficit hyperactivity disorder (ADHD) is rising globally. This could, in part, be due to the growing awareness of the neurodevelopmental condition and the rise in more efficient detection, diagnostic, and treatment methods.

The condition is characterised by various symptoms, such as an inability to concentrate, forgetfulness, difficulty in organising one’s time and following instructions. It also impacts cognitive flexibility – a key function that enables one to adapt to their environment by appropriately adjusting their responses.

Sleep is essential for normal human functioning and a key player in maintaining important cognitive and physical functions. A feature paper published in the Open Access journal Animals explores how sleep can impact ADHD-related cognitive flexibility in dogs. Using dogs as an animal model is an effective method to understand human behaviour and neurological conditions, including psychological disorders such as ADHD.

Attention deficit hyperactivity disorder and cognitive flexibility

Cognitive flexibility enables an individual to seamlessly adapt to a changing environment. In humans, it facilitates problem solving, decision making and creativity, and is associated with higher academic success and resilience in stressful situations.

Cognitive flexibility is associated with measuring intelligence but is different to the standard Intelligence Quotient (IQ) scoring system. For example, people with enhanced cognitive flexibility may have average IQ scores but exhibit enhanced adaptability to certain problems. In these situations, they are more flexible in their thought processes to adapt to change and reach ‘success’ despite potential unexpected hurdles.

In animals, this executive function has shown to enhance social interactions, survival, and reproductive success.

Research has previously shown that people with neurodevelopmental disorders like ADHD have impaired cognitive flexibility and may struggle during adverse life events or stressful situations more than those without ADHD. Furthermore, cognitive rigidity is linked to harmful, maladaptive behaviours including self-injury and suicidal thoughts.

Understanding ADHD-related cognitive flexibility is critical to design the appropriate treatment plans for people living with ADHD.

Dogs can help us understand human behaviour

Animal models are widely used to understand human disease and biological function. This includes understanding certain neurological conditions in animals which may develop and present in similar ways as they do in humans.

This is due to the genetic and physiological features humans share with many animals, including dogs, which make them excellent models to understand human disease and function.

Strict laws and regulations across the globe and within institutions are put in place to ensure appropriate welfare of animals in research, like dogs, is retained, and that animals are only used if there are no alternative, non-animal methods available to achieve meaningful results.

This study published in Animals was carried out in strict adherence with the Animal Welfare Committee of Eotvos Lorand University in Hungary.

The study aimed to understand specifically how sleep impacted cognitive flexibility of dogs that had traits of ADHD.

Better sleep may help cognitive flexibility

To better understand how sleep impacts ADHD-related cognitive flexibility, the researchers first validated the presence of ADHD in 58 family dogs. Owners of the dogs completed a questionnaire called the ‘Dog ADHD and Functionality Rating Scale’, which measured hyperactivity, impulsivity, inattention and related functional impairments – all symptoms of ADHD also found in humans.

They then set up a game to test their skills in cognitive flexibility. This involved placing a dog treat under one of two cups several times, with the treat remaining under the same cup for a few rounds – this is called the discrimination phase. The treat was then placed under a different cup after several rounds – this is called the reversal phase.

Tímea Kovács, lead author of the study, explains their observations:

Dogs with stronger ADHD-like traits were slower to learn the new treat location, mirroring the lower cognitive flexibility observed in humans with ADHD.

Following this, the dogs were rested for a nap and were monitored using electroencephalography (EEG), and then the game was set up again using the same format.

The researchers found that those dogs with higher ADHD scores that got sufficient sleep and repeated tasks had a greater improvement in performance, suggesting that sleep may play an important role in mitigating ADHD-related cognitive flexibility.

Márta Gácsi, senior author of the study, explains:

It seems that task repetition and sufficient sleep can help mitigate the cognitive flexibility impairments linked to ADHD traits in dogs.

Understanding ADHD in humans

The short- and long-term detriments of sleep deprivation have been proven in previous research. This includes its wide-spread impact on critical body functions such as the immune system, cardiovascular system, and hormonal regulation. Adequate sleep is critical to maintain cognitive well-being and physical health.

The research findings presented by this study deepen scientists’ current knowledge of sleep’s role in mediating critical executive functions such as cognitive flexibility, particularly in animals presenting with ADHD-like traits.

This information could be applied to our current limited knowledge of ADHD in humans, and how sleep can be further explored as a potential mitigator for cognitive rigidity in people living with ADHD.

Read more research on cognitive function by accessing the journal Behavioural Sciences, or see more research published in Animals. Alternatively, you can access the full journal list.