More people are being identified as neurodivergent because the definitions got broader, the screening got better, and entire populations that were previously overlooked are now being recognized. The numbers are genuinely rising on paper: autism prevalence in the U.S. went from 1 in 150 children in 2000 to 1 in 31 in 2022, according to CDC surveillance data. But that doesn’t mean human brains suddenly changed. It means the way we detect, define, and talk about neurological differences has shifted dramatically in a short period of time, and several forces are driving that shift at once.
The Diagnostic Definitions Expanded
One of the biggest structural changes happened in 2013, when the DSM-5 collapsed four separate diagnoses into a single category called autism spectrum disorder. Previously, autistic disorder, Asperger’s disorder, childhood disintegrative disorder, and a catch-all category called PDD-NOS were all treated as distinct conditions. After the revision, they became one spectrum. The criteria also shifted: three core symptom areas were consolidated into two (social communication became one domain, and restricted or repetitive behaviors became the other), and sensory sensitivity was added as a recognized feature for the first time.
This means someone who would have been told they had “Asperger’s” in 2010, or who fell into a diagnostic gray area, now falls under the autism spectrum. The condition didn’t change. The boundary around it did. The same pattern applies internationally: the World Health Organization’s ICD-11, which took effect in 2022, updated its own framework for neurodevelopmental conditions to align with similar principles.
Women and Girls Were Chronically Missed
Males are diagnosed with autism roughly 3.4 times more often than females. For decades, that ratio was interpreted as evidence that autism was primarily a male condition. The reality is more complicated. Research now shows that many women and girls with autism are skilled at camouflaging their symptoms, a pattern sometimes called masking. They model neurotypical communication, carefully manage their self-presentation, and stay close to peer groups to appear socially connected, even when they lack the skills to form deeper relationships.
This masking ability means girls tend to get diagnosed later than boys, and when they do receive a diagnosis, they often present with more severe symptoms or co-occurring conditions like intellectual disability or epilepsy. That’s not because their autism is inherently worse. It’s because they had to reach a higher threshold of visible struggle before anyone noticed. As clinicians have become more aware of how autism presents differently across genders, more women and girls are being identified, sometimes well into adulthood. That alone adds a large population to the count.
Adults Are Getting Diagnosed for the First Time
The surge isn’t limited to children. Adult ADHD diagnoses have climbed from 6.1% of American adults to 10.2% over the past two decades, with a particularly sharp increase since 2020. Several factors converged during the pandemic: people lost the external structure of offices and routines that had been quietly compensating for undiagnosed ADHD. Cognitive dysfunction from COVID and long COVID mimicked or worsened attention difficulties. And millions of adults, working from home with fewer coping mechanisms, began recognizing patterns in themselves for the first time.
For many of these adults, the traits were always there. A kid who “daydreamed too much” in the 1990s or a teenager who was told she was “just shy” often grew into an adult who developed elaborate workarounds. When those workarounds stopped working, the underlying neurodevelopmental difference became visible.
Social Media Changed the Conversation
TikTok, Instagram, and YouTube have become major sources of information about neurodivergence, and their influence is real but nuanced. Research analyzing TikTok videos with autism hashtags like #actuallyautistic found a complex relationship between autistic creators and the platform’s algorithm in shaping what autism “looks like” to viewers. Self-diagnosis tends to be more accepted on TikTok than on platforms where autistic communities formed around formal diagnoses.
For people who are already neurodivergent, social media can be genuinely helpful. Studies of autistic women found that after receiving a diagnosis, many used social media to connect with other autistic people and build what researchers describe as “neurodivergent-affirming identities.” One participant in a qualitative study estimated that 80 to 95% of her social media experience around autism was positive, giving her a sense of community and reducing isolation.
The flip side is that short videos describing ADHD or autism traits can be so relatable that almost anyone might see themselves in them. Difficulty focusing, social awkwardness, sensory preferences, and trouble with routines are common human experiences. The difference between a trait and a disorder is whether it causes persistent, significant difficulty across multiple areas of your life. Social media rarely makes that distinction, which can lead people to identify with a condition they may not actually have.
The Neurodiversity Movement Reframed the Language
The term “neurodiversity” was coined by sociologist Judy Singer in the late 1990s, drawing an analogy to biodiversity: just as ecosystems need diverse species to stay stable, human societies may need diverse kinds of minds. The concept offered an alternative to the medical model, which had traditionally described neurological differences using words like “deficit,” “disorder,” and “restricted.” Under the neurodiversity framework, these labels are seen as subjective and value-laden rather than objective scientific descriptions.
This shift matters because it changed who is willing to seek identification. When autism or ADHD is framed purely as something broken that needs fixing, people resist the label. When it’s framed as a difference that interacts with an environment not designed for you, more people are willing to explore whether it applies to them. The movement’s core insight is that disability often results from a mismatch between a person’s characteristics and their surroundings, not from the person alone. That reframing has made the entire conversation less stigmatizing, which in turn has made more people open to evaluation.
Screening Catches More Kids Earlier
The American Academy of Pediatrics now recommends developmental screening for all children at 9, 18, and 30 months, with specific autism screening at 18 and 24 months. These aren’t diagnostic tests. They’re standardized questionnaires that flag children who should be evaluated further. The key word is “all.” Universal screening means children are being checked even when parents haven’t raised a concern, catching cases that previous generations would have missed entirely.
CDC data illustrates just how much earlier detection has improved: children born in 2018 had 1.7 times the rate of autism identification by age 4 compared to children born just four years earlier. That’s not a change in biology over four years. It’s a change in how quickly the system identifies these children.
Environmental Factors May Play a Role
While most of the increase in prevalence reflects better detection rather than a true rise in occurrence, researchers haven’t ruled out environmental contributors entirely. Paternal age, maternal nutrition, prenatal infections, and exposure to certain environmental toxicants during pregnancy have all been linked to higher rates of neurodevelopmental conditions. The developing fetal brain is particularly vulnerable because the blood-brain barrier isn’t fully formed until about six months after birth, meaning substances that cross the placenta can have outsized effects.
Exposure to heavy metals like lead and mercury during the period around birth has been associated with autism in multiple studies, as have brominated flame retardants found in furniture and electronics. These factors likely account for a small portion of the overall prevalence increase, but they’re worth noting because they represent a genuinely different mechanism from improved screening or broader definitions.
Getting Evaluated Is Still Difficult
Even as awareness has grown, accessing a formal evaluation remains a significant barrier. A national survey of autism diagnostic centers found that nearly two-thirds had wait times longer than four months. About 15% reported waits exceeding a year, or had waitlists so backed up they stopped accepting new patients altogether. The top barrier cited by specialists was workforce shortages (69% of centers), followed by the sheer volume of referrals (61%).
Cost is another obstacle. While 84% of centers accept out-of-pocket payment, insurance reimbursement rates are often so low that many practices can’t afford to accept insurance at all. Evaluations can take anywhere from one to two hours at some centers to over eight hours at others. This combination of long waits, high costs, and limited providers helps explain why social media self-identification has become so common: for many people, it’s the most accessible path to understanding their own experience, even if it’s not a clinical one.
The result is a world where more people than ever are being formally diagnosed, more people are self-identifying based on online information, the definitions themselves are wider than they were a generation ago, and populations that were systematically overlooked are finally being counted. It’s not that everyone is suddenly neurodivergent. It’s that a lot of people always were, and the systems for recognizing that fact are finally starting to catch up.