“Every autistic person is different,” Purser says. “There is huge diversity within the spectrum.” So, while educating yourself about autism is important, so too is listening to the individual and not assuming that, because you’ve read something online, you know what it’s like for them. “Try and really put yourself in their shoes and empathise with their challenges,” Purser says.

For Alexander, autism is “like trying to learn three foreign languages at once”. He’d fail to pick up a date’s telegraphed signals, or get a joke when out with a group, which could make him feel sad, lonely, like “less of a human” and come across as insensitive, cold or rude.

A self-described square peg attempting to conform to a round hole, Alexander kept himself figuratively “behind closed doors” (sometimes literally) and acted as far as possible as society expected: an autistic survival strategy known as “masking” or “camouflaging”. He tried to recharge the “off the charts” energy drain of socialising through calming wellness practices such as meditation and stretching. He wore noise-cancelling headphones and dark glasses in an office, or worked remotely before the pandemic mandated it. When travelling, he factored in adaptation periods to reduce his distress at the transition to a new environment.

Not all of the estimated 700,000 children and adults in the UK (one in 100) on the autistic spectrum have been diagnosed: before the 2009 Autism Act, getting a diagnosis was “extremely hard”, Purser says, and even now isn’t exactly easy. But as (long, winding) pathways to diagnosis have opened over the past decade, public understanding that autism isn’t restricted to children has grown. And diagnostic criteria that were based predominantly on boys have developed to reflect how autism can be different in girls and women, which in turn has led to more adult men being diagnosed who might previously have been missed.

At least one in five people have brains that are “structurally and functionally different” from the norm, says Dr Tony Lloyd, CEO of the ADHD Foundation. The UK charity takes a “strength-based approach” to improving the life chances – and emotional wellbeing – of those not only with Attention-Deficit Hyperactivity Disorder, but also other (sometimes co-occurring) conditions such as autism, dyslexia, dyscalculia (difficulty with numbers), dysgraphia (difficulty with handwriting and fine motor skills), dyspraxia (difficulty with movement, coordination, organisation and speech) and Tourette’s (involuntary sounds and movements called tics) by emphasising their intelligence, “different abilities” and employability. Lloyd has friends who are psychiatrists, pediatricians and barristers with ADHD. He has an autistic accountant.

Strictly speaking, such differently wired people are “neurodivergent” or “neuroatypical”. A group, business or society can be “neurodiverse” – containing a multitude of neurotypes – but an individual can’t. But then Lloyd doesn’t refer to his ethnic minority or LGBTQIA+ friends as racially or sexually “divergent”. The preference is increasingly to say that someone is autistic or dyslexic – positive, identity-first language – rather than that they have autism or dyslexia. The move away from labels that stigmatise, exclude or shame people “for no other reason than that they think differently” is, says Lloyd, like the difference itself: to be celebrated.

Attention deficit is a misnomer for what is really a “surplus”, Lloyd says. An inability to filter out information, “like having six televisions in your living room, all on different channels, and you’re trying to watch one”.

ADHD can also impact “executive function” – emotional and impulse control, organisation and flexible thinking (adjusting to the unexpected) and cause procrastination because mentally “there are too many tabs open on your browser”. But if you’ve met one person with ADHD, he says, you’ve met one person with ADHD.

Now in his sixties, Lloyd discovered he had ADHD in his twenties. But only in 2015 did he seek a formal adult diagnosis in the UK (which was only possible from 2003) after life threw him several overwhelming “curveballs”. Since his diagnosis, he’s taken daily ADHD medication, which, in hindsight, would’ve made his life at school “a great deal easier”.

Academically successful, the young Lloyd didn’t fit the fidgety, misbehaving stereotype. He was instead medicated, unsuccessfully, for the depression and anxiety caused by his then-undiagnosed ADHD. He ultimately underachieved in an exam system that disadvantages neuroatypical students in a way not unlike the now outdated practice of forcing left-handed children to write with their right.

“In our assessment service, we see as many adults coming through as children,” says Ms Helen Goodsall, information manager at the British Dyslexia Association. Some of those adults, particularly those in their fifties, wouldn’t have been diagnosed in school because dyslexia “wasn’t really understood”. Affecting 10 per cent of people, dyslexia isn’t just difficulty with reading and writing but also processing verbal information and working memory. Someone who’s dyslexic may need a list of instructions verbally and in writing order to understand them, and forget the first entries by the end.

Affecting six per cent of people, dyscalculia is “30 years behind” dyslexia in public and academic understanding. Someone who’s dyscalculic may not grasp that £4,000 is punchy for a pair of (non-designer) sneakers, or inadvertently pay the date on their restaurant bill.

Adults who seek an autism diagnosis are often, says Purser, driven to do so by life events: the breakdown of a relationship, a change or loss of job and the structure or environment that provided, the bereavement of a supportive partner or family member. Sometimes it’s meeting other autistic people, or simply arriving at a place in their lives where they resolve to finally figure out why they’ve always struggled with certain things or felt different.

Already undergoing treatment for related anxiety, stress and depression, Alexander says that his autism was “squeezed to the surface” by the pandemic, which proved impossible to navigate without the support he needed.

Dyslexia is hereditary, says Goodsall, so a parent’s diagnosis can be prompted by their child’s. The call at the outbreak of the pandemic to work from home led many adults, both diagnosed and not, to ring the British Dyslexia Association’s helpline, as their long-established coping mechanisms – printing out and highlighting emails, asking a colleague to spell a word or just check this over – were disrupted.

Most of those who had been diagnosed had never told their co-workers or manager. Under the government’s Access to Work scheme, a diagnosis of a condition such as dyslexia, autism or ADHD entitles you to “reasonable adjustments” to help you do your job: coaching to develop strategies, assistive technology such as a laptop or speech-to-text software, or a desk in a quiet corner.

Dyslexia isn’t, however, covered by the NHS. A private diagnosis costs upwards of £600, which some schools, universities and employers will cover. (The British Dyslexia Association offers a corporate assessment service and referrals for individuals.) Autism is, so the National Autistic Society’s Purser suggests speaking to your GP in the first instance, but waiting lists for a diagnosis can be several years. Waiting lists for ADHD can stretch as long as eight years, says Lloyd, and “nearly half” of diagnoses are private – which GPs and NHS services can sometimes refuse to accept.

Research indicates that 30 per cent of entrepreneurs have dyslexia, ADHD or both; campaigning to redefine dyslexia, billionaire businessman Sir Richard Branson has described the condition as his “superpower”. Facilitating imagination, problem solving and an ability to see the big picture, “dyslexic thinking” has been responsible, as Branson trumpets, for great innovative leaps, from the light bulb to the car, air and space travel, and is a recognised skill on LinkedIn. But the neuroatypicality-as-superpower narrative can, Goodsall cautions, take away from people struggling to, say, fill in a job application – literally, since if a condition isn’t considered a disability, they won’t receive support. The reality is that only 22 per cent of autistic people are in any form of employment.

Lloyd echoes Branson’s call for businesses to embrace neurodiversity and, as the famous Apple campaign instructed, “think different”. Not least because one in five potential customers will also think differently.

“The world would be a much poorer place without ADHD,” says Lloyd, who doesn’t identify as disabled. Managed well, it can be “a real asset”, he says, noting his own ability to “almost visualise” an end result. But ADHD was very much not an asset for him at school and, when managed poorly or not at all, impairs employability and mental health. Around 40 per cent of people with ADHD, he says, have pervasive anxiety and depression. Mr Stephen Fry, the polymath and president of mental health charity Mind, who was expelled from school and imprisoned, believes his bipolar disorder may have stemmed from unmanaged ADHD.

Like tech, creative industries are “powered by people on the spectrum,” says Alexander. He’s in a position to promote neurodiversity in fashion and directly improve employment prospects and conditions for those who think different(ly), and thereby improve their mental health – and even prevent suicides. He might start a movement or charity, or work with an influential industry player to place neuroatypical people where they can play to their strengths.

“That’s the part I’m still figuring out,” he says.