Sensory Differences in Autism and ADHD: Sound, Light, Texture

You are sitting in a cafe. The person across from you is talking, but you can hear the fork at the table behind, the spotlight on the ceiling burns your eyes, the label of your sweater sits against your neck, and thirty minutes later you have to leave.

Some of the people who describe this scene have an autism diagnosis, some an ADHD diagnosis, some both. The scene is the same. The mechanism underneath is not always the same.

I do not have an autism diagnosis, and I am not going to give myself one. But as someone who received an ADHD diagnosis, I had labeled my own sensory overload for years as "being fussy," and reading about the sensory side of these two topics helped me tear that label off. In this article I explain what the research says, and I mark my own part separately.

Where the sensory side sits in the diagnostic manual

There is an administrative side to this distinction, and it is useful to know.

In the autism diagnostic criteria, sensory difference appears explicitly. In the DSM-5-TR, under the heading of restricted and repetitive patterns, over- or under-reaction to sensory input and unusual interest in the sensory aspects of the environment are listed (American Psychiatric Association, 2022). So the sensory matter is not a side note there; it is part of the criterion.

In the ADHD criteria, sensory difference does not appear as an item. The criteria are written in terms of attention, activity and impulsivity.

The wrong conclusion drawn from this is: "sensory sensitivity is specific to autism." The research does not support this. The study by Bijlenga and colleagues (2017) shows that atypical sensory profiles are also clearly seen in adults diagnosed with ADHD. Its not being written in the criteria does not mean it is not experienced; it only means that diagnosis does not go by that route.

What is known on the autism side

The review by Robertson and Baron-Cohen (2017) pulls this field together and says a few things clearly.

First, sensory difference is not exceptional in autism; it is a very commonly reported feature. Second, this difference is not one-directional: in the same person, oversensitivity in some channels and undersensitivity in others can be found together. Third, the matter is not only "hearing too much"; it concerns the way incoming information is sorted, grouped and placed in context.

Its everyday counterpart is this: a crowded environment is not only loud, it also becomes impossible to separate out. Sounds do not arrive one by one; they all arrive at once and with the same priority.

There is also continuity. In autism the sensory profile can usually be recognized from childhood and stays largely stable over the years. For this reason the developmental history is asked about during the diagnostic process: the question "did it start in adulthood" is a point of distinction.

What is known on the ADHD side

In ADHD the way sensory overload is described is a little different, because the story underneath is intertwined with attention.

The work of attention in suppressing what is irrelevant is strained in ADHD. The result is that a sound in the background does not stay in the background. While you try to listen to the person in front of you, the brain processes the hum of the air conditioner with the same importance. So the problem is not in the intensity of the sound but in the sound not being silenced.

The second piece is arousal level. In ADHD things go wrong with too little stimulation and with too much. This is why it is not strange to be unable to work in a quiet room but able to work in a cafe, and then to be overwhelmed in that same cafe within twenty minutes. I covered this duality in detail in the article on stimulation seeking.

The third piece is the signals coming from your own body. Hunger, thirst, the need for the toilet and tiredness are noticed late in ADHD, and by the time they are noticed they have already grown. I call this side body-signal blindness, and it is a silent factor that makes the sensory picture heavier.

Four channels, four separate stories

Talking about the sensory matter with a single word does not help, because the channels do not resemble each other.

Sound. The channel most often voiced in both profiles. On the autism side, what is often described is certain frequencies being unbearable and unpredictable sounds producing a sudden reaction. On the ADHD side, what is often described is sounds not being filterable: hearing the conversations at three tables at once. The two do not exclude each other.

Light. Fluorescent flicker, white lighting, screen brightness. On the autism side, a change in the visual environment can also be tiring: a new place means a new visual map. On the ADHD side, moving visual stimuli draw attention directly, which is why in an open office someone walking past the next desk wipes out the middle of a sentence. The article ADHD and the open office covers this part separately.

Texture. Labels, seams, fabric, a wet sleeve, the seam of a sock. In autism this topic is reported as a very marked pattern that has run since childhood and can determine clothing preferences for years. In ADHD it is described more as "intolerance of the moment": if the day is good there is no problem, if the day is bad the same sweater cannot be worn.

Smell and taste. The least talked about, the one that narrows life the most. The smell of certain foods can make a room unusable. Eating patterns can narrow in both, but for different reasons: in autism, texture and predictability are described as the decisive things; in ADHD, the fading of interest and difficulty with planning come to the fore.

Oversensitivity and undersensitivity in the same person

This is the most confusing thing, so I am writing it separately.

The same person can be unable to stand sounds and yet turn the music all the way up. They can be unable to tolerate touch and yet find relief under a weighted blanket. This is not an inconsistency.

The distinction is here: the stimulus you choose and the stimulus that comes to you are not the same thing. The music you turn on yourself is predictable, you know when it will end, you can cut it when you want. The conversation at the next table is unpredictable and the control is not with you. What determines the sensory load is often not intensity but control and predictability.

This is also the most useful piece of information for the setup you can build at home. Chasing predictability works better than chasing silence.

Why the distinction is so hard

There are three reasons, and all three blur the diagnostic process.

Masking. In adulthood a person learns to hold their reaction inside. Someone who looks "like they're managing" from the outside may already have exceeded their capacity on the inside. I wrote about this side separately in the article on masking and in the article on masking in autism and ADHD.

Avoidance is invisible. If a person has not gone to crowded restaurants for years, their sensory difficulty is not visible either. Avoidance does not solve the problem; it only hides it. When going to an assessment, the sentence "I don't have problems anymore" needs to be dug under: do you not have them, or do you just never enter those environments?

There are other causes. Anxiety, sleep debt, migraine, thyroid problems and some vitamin deficiencies can lower sensory tolerance. Sensory overload alone does not point to a diagnostic direction; differential diagnosis exists for this.

When describing sensory overload, "how much does it bother you" is the wrong question. The right question is this: after that discomfort, how much of your day do you lose?

Recovery time is the real matter

This is the most skipped part of the sensory discussion.

The overload itself may last a few minutes. The real difference is in what happens afterward. Some people leave the cafe and recover in ten minutes. Some lose the whole evening, cannot speak, cannot decide, and it spills into the next day.

This recovery time is more decisive for functioning than the overload itself. It is what you need to take note of both when going to an assessment and when organizing your life. I wrote the details in the article on sensory overload and in the article on meltdowns, shutdowns and emotional outbursts in ADHD.

A setup that works in daily life

Even though the mechanism differs, the logic of arranging the environment is largely shared. A few concrete things:

• Take the channels one at a time. The sentence "I'm struggling sensorially" cannot be solved. "Fluorescent light and background conversation" can be. For a week, write down which channel sinks you and when.
• Move control to yourself. Headphones, sunglasses, a sound you choose. Reducing the stimulus is not always possible, but changing who chooses it often is.
• Build an exit plan. Knowing how you will leave when you enter an environment lengthens the time you can stay in it. Going in your own car or saying in advance "I'll stay half an hour" is the simplest form of this.
• Plan for after the overload. Do not put a meeting after a heavy day. Recovery time is not a luxury, it is a line in the budget.
• Keep home constant. What rests you most sensorially is familiarity. Never changing the light and arrangement of one room at home makes the load outside bearable.

From this list, the item I benefited from most was "take the channels one at a time." In the period when I worked in an open office in Ankara I thought the problem was "the crowd"; when I kept notes for a week, I saw that the problem was not the crowd but the movement in the corridor behind me. Turning the desk was enough.

When to see a specialist

Sensory difference alone is not a reason for a diagnosis. An assessment becomes meaningful in these situations: if your recovery after overload takes days, if because of this you really disrupt your work or relationships, if you have a very marked sensory pattern that has run since childhood and this pattern restricts your life.

I described what an assessment involves in the articles on autism diagnosis in adulthood and how adult ADHD is diagnosed. I also covered the possibility of the two occurring together in the article on AuDHD.

The sentence that helped me most, for my part, was this: sensory overload is not an endurance test. Managing to endure is not an achievement; it only makes the next day more expensive.