Chapter 1.
Background
ADHD, short for attention deficit hyperactivity disorder, was originally known as the "hyperkinetic reaction of childhood." It wasn’t until the 1960s that the American Psychiatric Association officially recognized it as a mental disorder, with more understanding emerging in the 1980s. ADHD diagnoses began to rise significantly in the 1990s, likely due to several factors: doctors became better equipped to identify ADHD, and parents became more aware of the condition. They were more likely to report symptoms in their children, and it’s possible that more children were genuinely developing ADHD. Approximately 5% of children and adolescents worldwide are affected by ADHD. The study suggests the prevalence of symptomatic adult ADHD globally is 6.76%. During October, ADHD Awareness Month aims to heighten awareness of this condition, which can affect a person’s work, school performance, relationships, and self esteem.

Boys are diagnosed with ADHD over twice as often as girls, though this doesn’t mean girls are less affected. Many girls go undiagnosed, partly because they usually show different symptoms, and studies have historically focused more on boys. To be more specific, boys and men tend to display more hyperactive and impulsive behavior, while girls and women are more likely to have inattentive ADHD. Males and females also show different patterns of comorbidity, which is when another condition occurs alongside ADHD. Males are more likely
to have externalizing disorders, such as substance misuse, conduct disorders, and antisocial personality disorders. Meanwhile, females are more likely to have internalizing disorders, such as anxiety, depression, somatic symptom disorders, and bulimia. Hormones can also worsen ADHD symptoms in females. These changes in symptoms may delay diagnosis.

ADHD does not have a single identifiable cause, and the known risk factors seem to be non-specific. Factors like chromosomal microdeletions (e.g., VCFS), rare large CNVs, extremely low birth weight, and prematurity are linked to a variety of neurodevelopmental and psychiatric conditions rather than being exclusive to ADHD. Chromosomal microdeletions,
such as those seen in Velocardiofacial Syndrome (VCFS), involve missing segments of DNA that can affect brain development and increase the risk of cognitive and behavioral disorders, including ADHD. Similarly, rare large copy number variations (CNVs) are structural changes in the genome that can impact multiple genes and have been associated with various
neurodevelopmental conditions, rather than ADHD alone. Other factors include genetics, that is, ADHD often runs in families, as studies reveal that parents and siblings of individuals with ADHD are more likely to have the condition as well. What’s more, environmental factors like lead exposure as a child or problems with the central nervous system during development may also cause people to have ADHD.

1-1 Attending to / Caring for / Responding to the needs of workers with ADHD
ADHD is usually identified in elementary school, but adults can also experience symptoms and get diagnosed later in life. ADHD symptoms often stick around into adulthood, but they can change as people get older. Inattentiveness tends to remain, while hyperactivity and impulsivity usually decrease over time. ADHD can be diagnosed in both children and adults, but adults need to have shown symptoms beginning before the age of 12. Some experts think ADHD may be underdiagnosed in adults because the criteria were originally designed for kids. A key
difference in diagnosing ADHD between children and adults lies in the number of symptoms required. For adults and teens aged 16 or older, the threshold is five symptoms of inattention or
hyperactivity-impulsivity, compared to six for younger children. Moreover, as individuals with ADHD transition into adulthood, they often choose jobs or environments that align with their
distinct thinking styles. This can help them manage their symptoms and may contribute to the feeling that they’ve “outgrown” the condition.

The symptoms of ADHD include being easily distracted, hyperactivity, difficulty with time and emotion management, poor organizational skills, and inattentiveness. People with ADHD may also exhibit positive characteristics such as increased creativity, the ability to hyperfocus, and high levels of energy. Although people with ADHD all suffer the debilitating effects of the disorder, it’s not necessarily a barrier to the highest levels of achievement in their professions. Countless successful people have ADHD, such as Simone Biles, Emma Watson, Bill Gates, and Albert Einstein. People with ADHD often have unique strengths due to the way their brains work. They're known for being spontaneous, creative, energetic, intuitive, and
imaginative. Their ability to hyperfocus on topics that excite them is like their superpower. They think outside the box, generate original ideas, and use their high energy to work harder and faster. Many also learn to turn impulsivity into spontaneity, using it as a positive force in various aspects of life. Success often comes when people with ADHD find careers that align with their natural talents, such as creativity, innovation, or physical activity. Some great fits include being an entrepreneur, artist, designer, teacher, or athlete.

In university environment settings, sensory adaptations, like improved lighting, noise control, ergonomic seating, and flexible study areas, can make a big difference in helping them focus and avoid sensory overload. Using furniture that is not suitable can cause fatigue and pain. Students' inattentive behaviors are influenced by their peers as well.

As people with ADHD grow older, their symptoms might change or reduce. The way ADHD presents itself can vary depending on the setting; what’s disruptive in one place may be normal in another. Supportive environments, like flexible workspaces, help adults with ADHD thrive, especially when distractions are limited. Incorporating movement or choosing active jobs can also boost focus. Cognitive Behavioral Therapy is an effective tool for reducing symptoms and improving overall well-being. Cognitive load and attentional engagement are strongly affected by the surrounding environment in the users’ presence. Research shows that when the working loads are high, people with ADHD often develop strategies to cope with cognitive challenges. Another area of research in this paper is alpha power modulation, particularly central-occipital alpha ERD, which is linked to attentiveness and visual information processing, indicating increased brain engagement during tasks. This insight supports this thesis by highlighting the importance of creating designs that help sustain attention and manage cognitive load.

1-2 Maximizing the Productivity of People with ADHD
The way ADHD brains work is fundamentally different from neurotypical brains. Based on the research, the ICNU framework is how the nervous system of people with ADHD is
wired. ICNU stands for Interest, Challenge, Novelty, and Urgency, and basically, if a task you’re trying to do is missing one of these four things, it’s highly possible that you’ll freeze up
and refuse to do it. They perform more efficiently and effectively when the tasks are interesting, challenging, novel, or urgent. Instead, the neurotypical workers' driving force comes from the
concept of importance, rewards, and consequences intrinsic to the task. That is the reason why many people with ADHD tend to procrastinate. Neither approach to working is better than the other; they’re simply different ways of getting things done, each aligned with unique cognitive styles. However, if the work environment is only designed and friendly for a neurotypical brain structure, it can impact mental well-being and even lead to burnout for neurodivergent brains. This is because on the outside, some adults with ADHD may look like they are fine, but in reality, they are making an excessive effort to keep up.

Research shows that people with ADHD often experience hyperfocus that can enhance motivation and productivity, while hyperfocus can feel like a positive "flow" state, it can also lead to time loss and added stress, causing muscle tightness or fatigue afterward. This hyperfocus is linked to executive function difficulties, which make shifting attention harder and contribute to more severe ADHD symptoms. High anxiety further strains focus and executive function, increasing mental effort and error rates. During the pandemic, these challenges worsened for those with ADHD due to disrupted routines and limited spaces, highlighting the need for adaptable, calming environments.

The result of getting into the hyperfocus stage is related to challenges of executive function (EF) and more severe ADHD symptoms. However, these EF challenges did not specifically address hyperfocus during rewarding activities. Although hyperfocus can sometimes enhance motivation for engaging in such tasks, it may also exacerbate ADHD symptoms by disrupting daily routines and having a negative impact on mental health. Comparing hyperfocus to perseveration, a more rigid type of focus that makes switching tasks difficult. While hyperfocus is often seen in a positive light, like the flow, it can also cause problems, like losing track of time or struggling to shift attention when needed. The research indicates hyperfocus
might have unique characteristics in ADHD, including both its benefits and downsides.

Emotion dysregulation is tied to challenges in maintaining balance during hyperfocus, as individuals with ADHD often struggle with shifting attention and regulating emotions effectively. Research suggests that ADHD individuals
benefit from adaptable, sensory-friendly environments that reduce stress and enhance focus by incorporating movement-friendly and flexible furniture designs. Studies indicate that dynamic seating, such as rocking or flipping stools, can help regulate sensory input and support emotional and cognitive self-regulation in neurodivergent individuals.

Furthermore, executive function (EF) challenges in adults with ADHD highlight difficulties in task-switching, organization, and time management, which can lead to inefficiencies and increased cognitive load. A workspace that accommodates these challenges should offer intuitive task organization and minimize disruptions during transitions. Studies have shown that structured workstations with clear task differentiation and integrated timing mechanisms can aid ADHD individuals in managing hyperfocus, improving productivity, and preventing time blindness. Adjustable and interactive furniture solutions that support frequent shifts in focus and task engagement have been found to enhance work efficiency and reduce
executive function strain.

1-3 Contrast conventional designs with existing experimental designs
The conventional furniture of a workplace usually does not meet the particular needs of an ADHD adult in terms of flexibility, consideration for sensory problems, and proper ergonomic design. For example, traditional office desks and chairs often feel pretty stiff and uninviting, especially for someone with ADHD who might need a bit of movement to stay focused.
Regular office chairs are usually fixed in place, which can make it hard to get comfortable if you're fidgeting or need a change in position. Alternatives like kneeling chairs (Figure 3) or balance balls (Figure 4) give a little more freedom to move, which can help burn off some of that excess energy and improve focus. However, kneeling chairs can put a strain on the knees, making them unsuitable for those with existing knee pain or injuries. They may also restrict mobility, which can be inconvenient in dynamic work environments. Some users experience discomfort during the adaptation period, and these chairs may not be ideal for individuals with certain medical conditions, such as severe knee or back issues. Additionally, overuse may lead to muscle imbalances due to excessive reliance on core muscles. Standing desks (Figure 5) offer a nice break from sitting, but they often don’t address other sensory needs, like providing a more calming or organized workspace. In addition, prolonged standing can lead to fatigue, foot pain, and muscle strain, especially for those unaccustomed to it. Poor posture or an improperly adjusted desk may contribute to back pain, while extended standing has also been linked to circulatory issues like varicose veins.

Then there's the issue with office layouts. Open-plan offices, while great for collaboration, can be a nightmare for someone with ADHD due to noise and visual distractions. Something like a privacy pod or modular workstations with adjustable partitions can help create a quieter, more controlled environment, making it easier to concentrate.

Storage is another area where standard office furniture falls short. Traditional filing cabinets and open shelves can add to the chaos, which makes staying organized even harder. Solutions like color-coded bins, labeled compartments, or even digital task management tools built into the furniture can make a huge difference in keeping things neat and reducing the mental load. At the end of the day, while there are some good options out there, most of the furniture we see in workplaces isn’t really built with ADHD in mind. It often requires a mix-and-match approach to find the right balance of flexibility, organization, and sensory-friendly features. Moreover, most designs are based on either aesthetics or general functionality rather than inclusivity and personalization, which makes them unsuitable for neurodiverse users. This section points out the failures of conventional furniture while investigating experimental designs that place functionality, inclusivity, and adaptability in the foreground for ADHD users.

Spending hours at a fixed desk without an adjustable feature and sitting in a traditional chair could be a challenge for an individual with ADHD. As Figures 6 show, even though there’s function for sit and stand position for people to change posture that helps people to be more productive and less distracted, the storage, however, it’s not transparent, so people with ADHD may easily forget what things they put inside because sometimes their space memory is not as good as that of neurotypical people. Therefore, the sit-and-stand desk is still not
friendly for people with ADHD. Similar problems, such as the cover not being transparent, are also shown on the cabinet shelf
in Figure 7. As for Figure 8, it seems to have abundant functionality, it’s important to consider the assembling process since it has many parts that the user has to spend more time
and effort to assemble. People with ADHD often struggle with tasks that require sustained attention, organization, and step-by-step problem-solving. Therefore, assembling