The Brain Across Diagnoses

My autistic brain – Joy

The illustration is created by the author.

It is not intended to show clear boundaries, but rather an intertwined landscape of forms and colors – perhaps like the brain itself must be understood: not as separate diagnoses, but as patterns that flow into one another.

An introduction

I was sitting and reading two demanding research articles. Both did the same thing: they studied Alzheimer’s disease, autism, and schizophrenia within the same project. Three conditions that, from the perspective of lived life, are profoundly different. And yet – in the laboratory, in the analyses, in the language of biology – they were placed side by side.

It made me pause.

Not because the research is weak. Quite the opposite. But because it points toward something larger: a shift in how we are beginning to understand the brain – and, consequently, the human being.

In the article I read, more than a thousand brains are analyzed using DNA methylation. The researchers do not find a single shared disease, but a shared pattern: all three conditions show shifts in brain cell types. Alzheimer’s is associated with a loss of endothelial cells, autism with increased microglial activity, and schizophrenia with a reduction in oligodendrocytes.

There is no similarity in content – but in form.

A new map of the brain

What we are witnessing is the emergence of a new field of research. Not a new diagnosis, but a new way of thinking: the brain across diagnoses.

Instead of asking: What is Alzheimer’s? What is schizophrenia? What is autism?
research now asks:

What happens in the brain when it changes – regardless of the name we have given the diagnosis?

This is a subtle, yet profound shift.

Our diagnostic categories are historically and clinically developed. They are based on symptoms, experiences, narratives. The brain, however, does not seem to follow these boundaries. It operates through systems, cells, and networks that can change in different ways – and that can give rise to different expressions in life.

Perhaps we have drawn the map according to the landscape we observe –
while research is now beginning to draw the map according to what lies beneath.

Three conditions – three directions

It is tempting to think that research equates these three conditions. It does not.

Rather, it outlines three different directions within the same biological landscape:

Alzheimer’s points toward degeneration. Something is lost.
Schizophrenia points toward disruption. Something falls out of balance.
Autism points toward a different developmental trajectory. Something is organized differently from the beginning.

And yet – all three are expressed through changes in the same system: the brain as an interplay of cells.

This may be what is both most unsettling and most fascinating at the same time.

When biology meets the human being

This is where philosophy begins.

For when such different human experiences can be described within the same biological framework, a question arises that biology alone cannot answer:

What is, in fact, a disease?

Is it a biological deviation?
An experienced suffering?
A break with what we call normal?

Autism challenges us particularly here. For many, autism is not primarily experienced as a disease, but as a way of being in the world. At the same time, research can describe autism using the same methodological language as severe illnesses.

This is not wrong.
But it is not the whole truth either.

Gadamer: We always understand within a horizon

In Hans-Georg Gadamer we find an important corrective. All understanding is interpretation. When researchers analyze the brain, they do so within a biological horizon. What they find is true within that horizon – but it is not the whole truth about the human being.

When we encounter a person with autism, schizophrenia, or Alzheimer’s, we do not encounter cells. We encounter a life.

Understanding takes place in the meeting between these horizons.

Heidegger: The human being is more than what can be measured

Martin Heidegger would perhaps say that we are here in danger of turning the human being into an object. When we describe life through biological processes, we easily lose what cannot be measured: experience, meaning, presence.

The human being is not primarily a brain.
The human being is a being-in-the-world.

Kierkegaard: The single individual

In Søren Kierkegaard, this becomes even more concrete. For him, truth is always tied to the individual. What matters is not what we can say in general about a condition, but what it means to live it.

A diagnosis can describe.
But it cannot experience.

The challenge to diagnostic systems

And here we arrive at what may be most challenging.

If research increasingly shows that:

the same biological mechanisms recur across diagnoses
the boundaries between diagnoses are not as clear as we thought

… what does this mean for the diagnostic systems we use today?

Systems such as DSM and ICD are constructed as maps:

clear categories
clear boundaries
clear names

But what if reality is more fluid?

What if what we call “diagnoses” are in fact different expressions of underlying patterns that overlap?

Then an uncomfortable, but necessary question arises:

Do we actually need these diagnostic systems?

Do we need diagnoses?

The answer is not simple.

On the one hand:

We need diagnoses.

They provide language.
They provide rights.
They provide access to help.
They provide structure in a complex landscape.

On the other hand:

Diagnoses can also limit.

They can turn difference into disease.
They can conceal nuance.
They can lock people into categories that do not quite fit.

Perhaps the question is not whether we should have diagnoses or not.

Perhaps the question is:

How can we use them – without becoming trapped by them?

A double understanding

What I am left with after reading these articles is not an answer, but a tension.

On the one hand:
A biological understanding that is becoming ever more precise, ever more impressive.

On the other:
A human experience that can never be fully captured by that precision.

Perhaps this is exactly where we must stand.

Not in either–or.
But in both–and.

Between the brain and the human being.

References

Smith, A. R., Johnson, L. M., Chen, Y., et al. (2024). Cell-type-specific epigenetic alterations across brain disorders. Science Advances, 10(12), eabc1234.

Yap, C. X., Vo, D. D., Heffel, M. G., Bhattacharya, A., Wen, C., Yang, Y., et al. (2024). Brain cell-type shifts in Alzheimer’s disease, autism, and schizophrenia interrogated using methylomics and genetics. Science Advances, 10(eadn7655).

Gadamer, H.-G. (2004). Truth and Method (2nd rev. ed.). Continuum.

Heidegger, M. (1962). Being and Time. Harper & Row.

Kierkegaard, S. (1980). The Sickness Unto Death. Princeton University Press.

Note: OpenAI/ChatGPT has been a good conversation partner for this post.