What is the difference between neurodivergence and mental illness?
Neurodivergence and mental illness are not wholly unrelated. Thanks to mental health advocacy work, there’s been a movement in recent years to depathologize (and from there, to destigmatize) the many differences in how a person’s brain can function. While once, many of the conditions that fall under the neurodivergent category would have been considered mental illness (or under the mental illness umbrella), we now understand them to be common ways that a human brain can function, even if they are different to our cultural norm.
From this understanding, there’s been a push to question: what is “normal” brain functioning? When we understand that variation is common and to be expected, the idea that there is one “right” or “normal” way for a brain to function comes into question. This is the process of destigmatizing neurodivergence that follows naturally from the work of depathologizing differences.
But because we live in a culture built mainly around how neurotypical’s (the term commonly used for people without any sort of neurodivergence) brain and social functioning, it’s not entirely possible to separate the two. Those who are neurodivergent often experience symptoms of mental illness due to the difficulty of trying to function in a world not built for how their brains work. And, when you get beyond the more commonly experienced or easily understood types of neurodivergence, the distinction between the two starts to get a little bit more complicated.
Let’s dive in! First, what do we mean by “neurodivergence” and “mental illness?”
What is neurodivergence?
When we talk about neurodivergence, we’re talking about any condition that impacts how the brain functions. That means differences (again, from what is considered the “norm”) in how someone learns and processes information, how someone focuses, and how they process sensory input–without clinical distress.
Most commonly accepted to be under the neurodivergent umbrella are things like autism, ADHD, dyslexia, and even Tourette’s syndrome. However, some frameworks include other conditions, like OCD–there is still ongoing debate on precisely what qualifies as neurodivergence and where the line between neurodivergence and mental illness falls.
One of the common diagnostic criteria for neurodivergence vs. mental illness is onset–conditions that fall under the neurodivergent umbrella are typically present from birth or early childhood, though they may not be diagnosed until later in life!
Neurodivergence, or neurodiversity, changes the framing from “what is wrong with this brain” to “what does this brain need to function optimally.”
What is mental illness?
Mental illness, then, would be the conditions that cause an inability to function, or are severe enough to cause the clinical distress that we mentioned earlier. Clinical distress here would be when a condition interferes with daily functioning so much that functioning is effectively impossible; it’s also often coupled with a sense of deep self loathing, withdrawal from regular activities, and (often a self imposed) social isolation.
Commonly understood mental illnesses are things like depression and anxiety, but they are not the only ones! Currently under the mental illness umbrella are also bipolar disorder and schizophrenia, though both of them are actively debated amongst neurodiversity advocates, which we’ll get into a little later.
Unlike neurodivergence which is present from birth or early childhood, mental illnesses can occur at any point in time in response to traumatic events, biology, or changing circumstances.
What is the distinction between neurodivergence and mental illness?
There are a few different ways we currently distinguish between mental illness and neurodivergence. Some of the criteria to differentiate between the two is scientific or diagnostic criteria, while some is based on lived experience, since the concept of neurodivergence itself (and the movement to depathologize it) was born out of autism advocacy.
For example, many (though not all) folks with neurodivergence often see it as a core part of their identity (ex. “I’m autistic” vs “I have autism,”), while mental illness is not as often seen as part of oneself, but something one manages.
Neurodivergence is describing a “divergence” or difference (from our understanding of what the “norm” is) in how someone’s brain functions or processes information, whereas mental illness is describing conditions that impair that functioning altogether.
The treatment goals for the two are also different; for neurodiversity the treatment goal is typically (lifelong) accommodation, whereas for mental illness the treatment goal is symptom relief. However, while the treatment goals for the two may be different, the ways in which these treatment plans are implemented can look very similar (medication, therapy, sometimes environmental changes, etc.).
Do mental illness and neurodivergence ever overlap?
The overlap between mental illness and neurodivergence is quite common, and there is still ongoing debate about what exactly the strict line between neurodivergence and mental illness is
As we said. The concept of neurodivergence (and the effort to de-pathologize it) came out of autism advocacy, and overtime it began to include other so-called disorders like ADHD, which are described as “neurodevelopmental,” but other conditions which are more likely to be considered mental illness–such as bipolar disorder and schizophrenia–also have neurological components, which makes that divide a bit messier.
And while the onset for mental illness can occur at any time, many folks have a genetic predisposition to certain mental illnesses, and suffer from chronic depression or anxiety from a young age. This means that symptoms can be episodic, or increase & reduce at different times in their lives, while never really going away, further muddying the distinction between the two based on the “onset” criteria we discussed earlier.
Neurodivergent folks also commonly experience what we understand to be “secondary” mental illnesses. For example, folks with ADHD or autism often have increased anxiety from the constant masking, and enormous effort it takes trying to make their brain work in a world built around brains that work differently. And social isolation caused by communication challenges or differences in how social cues are understood is common in those with neurodivergence, which can lead to or exacerbate symptoms of depression.
If advocacy work has been aiming to depathologize neurodivergence, why is it still something that is diagnosed?
While there has been a lot of work to depathologize and destigmatize differences in how our brains function, there are certain criteria that give someone a neurodivergent diagnosis. This is mainly because we still live in a world designed for neurotypicals, and a diagnosis helps individuals access care, support & accommodations, as well as get insurance coverage for that care, support & any needed accommodations.
Testing, assessment and diagnosis can also help folks determine how “severe” their experience is, as most conditions exist on a spectrum. This is all information that will help them make accommodations for themselves and access the type of support they need, while removing some of the guesswork they’ve had to do for so long.
