I was asked about this stigma in private, but I think this might be good for others to be aware of as well, seeing as even medical professionals tend to overlook this fact. Which is the proven reason why people with neurodevelopmental disorders commonly have weight problems.

So, let’s start from the basics. In neurodevelopmental disorders, weight problems are a well-known problem. Both sides of the coin are highly common, obesity(overweight) and emaciation(underweight). The same applies to anorexia and bulimia. It’s a hard subject to talk about, incredibly stigmatized, regardless of there factually being reasons behind this that explains it all. Yeah, there are multiple, although my previous use of singular will become clear after you read everything that I am about to write.


First, we would have to look at the other co-morbid conditions with neurodevelopmental disorders.

The first part you will notice is most interesting, which is that neurodevelopmental disorders (almost) always co-morbid with other neurodevelopmental conditions. It’s like ADHD and autism spectrum disorders extremely often happen at the same time. Same for how both conditions very often happen together with either dyslexia, dysgraphia, or dyscalculia, or even with a combination of these conditions. Let alone motor disorders, which even explain some parts of the conditions…

However, there are also some other conditions. These would be anxiety disorders, depressive disorders, epilepsy, and sleeping disorders. And this last one is the most important one of all.

Now, in neurodevelopmental disorders, there’s a well-known connection with so-called “circadian rhythm disorders”, which are a form of sleeping disorders that are classified by the internal body clock being impacted, kind of straying away from truly being sleeping disorders as sleeping problems is just 1 part of this. These conditions are known to impact hormones, including specifically the hormone melatonin.

For those who don’t know what melatonin is. It’s the hormone your body produces in response to darkness, which makes you feel sleepy at night. In a normal person, your body would start producing melatonin between 6 and 9 in the evening, depending on some factors, including age. It would reach its peak between 2 and 4 in the night and would then decrease until almost nothing in the morning when you wake up. At the moment when melatonin is increasing, cortisol usually decreases. The exact science behind cortisol in relation to the sleep-wake cycle is unknown, but it’s known that it plays a part, especially when it comes to waking up and staying awake.

Melatonin does have another important hormone that it interacts with, which is leptin. And it shouldn’t be surprising that leptin is connected to… Yep, your body weight.
Leptin is known to be the hormone that sends the signal to your brain that helps you feel full and be less interested in food. It’s made primarily in your fat cells, your stomach, and your intestines. However, if you have low levels of leptin, the opposite will happen, as you will feel more hungry. And if you have either a constantly too-high or too-low level of Leptin, it’s rather obvious what will happen.

Taking one step back, melatonin is supposed to regulate leptin. And this is not a true problem in all circadian rhythm disorders. As in most of them, your body clock is set a few hours too early, or a few hours too late, but it’s still a 24-hour internal clock like other people.
However, when it comes to specifically non-24-hour sleep-wake disorder, this is different. In non-24, your body clock will not keep to a 24-hour rhythm, causing your hormone regulation to be impacted as well. Beyond just that, in non-24, your body isn’t able to register light and darkness, which further impacts your hormone regulation.

As I said before, melatonin is produced in response to darkness, but if you don’t have that indication, your body will have to guess when it needs to make melatonin. And depending on the specific situation, this could cause extreme problems in your melatonin production. For example, there are known cases where melatonin production spiked way and way too high. While there are also those where the melatonin production is constantly way too low. And there are even known cases where melatonin production goes all over the place, making it one moment way too much, and another nothing anymore, followed by yet another huge spike. Both have specific problems. However, all of them have 1 common problem they all share, which is the effect on leptin.

All in all, low levels of melatonin will usually lead to low levels of leptin, causing you to feel (too much) hunger. While high levels of melatonin will usually cause the exact opposite. In the case of people with non-24, this doesn’t necessarily have to mean only the night, hence you often see weight problems among these people. And it’s good to be aware that sighted people with non-24 (almost) always have a neurodevelopmental disorder as well.


The second is well-known about neurodevelopmental disorders, and so often forgotten how far it impacts someone. I am referring to something most will know as sensory processing disorder.

Sensory processing disorder is a symptom of almost all neurodevelopmental disorders. Some people will incorrectly identify it as a separate condition, which it is not. The name sensory processing disorder refers exactly to what it means, as it affects how your brain processes sensory information. Now, a lot of people tend to think about vision, sound, smell, taste, and touch when it comes to sensory information. However, it also impacts your vestibular system(sense of balance and spatial orientation), proprioceptive system(sense of body awareness and detection and control of force and pressure), and most importantly the interoception system(sense of the internal state of the body). Yeah, you could re-read the first explanation to figure out the point. For those who don’t want to, it’s as simple as sensory processing disorder being able to cause your brain to not process the information shared through the hormone leptin correctly.

All I will add here is the fact that sensory processing disorder works 2 ways, as your brain can process the sensory information as too much or too little. For example, someone’s brain could process sensory information in such a way that it thinks your body is way too hot, causing your body to excessively sweat. The same applies to hunger, it could lead to you feeling either no hunger or way too much hunger.


The third is directly related to the first and not exclusively known for neurodevelopmental disorders, which is leptin resistance. To be clear, this is specifically about obesity.

Now, someone who is obese has a lot of fat cells, resulting in high leptin production and high leptin levels. This should mean the brain knows that there’s enough energy and therefore you to have no hunger and no longer eat. However, leptin resistance is very similar to non-24 and sensory processing disorder regarding your brain being unable to correctly register something. In this case, it’s your leptin levels. Someone with leptin resistance would have high levels of leptin in the blood and the brain would still think you need to eat. You don’t need to be obese to have this condition, but it’s unlikely you won’t get obese if you have this condition. And the worst of it, there’s no proven treatment for every presentation of the condition at this moment. It could be life-long, depending on your specific situation with the condition, meaning you would face constant discrimination for something you factually can’t do anything about.

Some of the theorized causes of leptin resistance are the same as what is believed to be among the causes of neurodevelopmental disorders, hence this condition is more common among these people.


These are the 3 I know about, but possibly there are even more. They all share the common problem of the hormone leptin, which was discovered by scientists in 1994, but even now there’s no full understanding of this hormone. The fact that we have doctors specialized in specific parts of the body will in the future cause even greater problems than we are already facing. An average psychologist, neurologist, or dietician would know nothing about leptin. While these are the 3 professionals you would face if you’re someone with obesity and a neurodevelopmental disorder. It’s sad, as we should be working for healthier people, but in most of the world, this is an impossibility due to the compartmentalization of care. It’s not like this is the only part of the care system we see this at. Take for example genetic conditions, they’re far more common than we know due to the fact that people are generally not checked for them. Here in Europe, you will often get the easy stickers of “autism” and “ADHD”, due to the genetic tests costing thousands of Euros. However, the fact that we don’t do these tests causes people who are misdiagnosed to suffer, receiving the wrong care, often for years, sometimes even their whole lives. I sincerely wonder when the world starts to understand that the care system is the most important part of a country and something that should be the sector where the most money is at, not defense which is the case right now in almost every country worldwide…