Research Recap with Skye: Hay Fever and ADHD

Summary

Podcast Summary: Hacking Your ADHD

Episode: Research Recap with Skye: Hay Fever and ADHD
Host: William Curb
Guest: Sky Waterson
Date: July 31, 2026

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Episode Overview

In this Research Recap episode, William Curb and Sky Waterson dive into a recent meta-analysis paper: Bidirectional association between Allergic Rhinitis and Attention Deficit Hyperactivity Disorder: Systematic review and meta-analysis. The episode explores whether there’s a real connection between allergic rhinitis (hay fever) and ADHD, highlighting key findings, methodological insights, and real-life implications. The tone is thoughtful and inquisitive, laced with surprise at the strength of the correlation and curiosity about the broader implications.

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Key Discussion Points & Insights

1. How Did This Topic Come Up?

• Curiosity Sparked ([00:51]):
  • William suggested checking for a connection between hay fever and ADHD, based on his own suffering.
  • Sky’s team found an unexpectedly large body of research on the topic.

"It turns out there's a ton of people who have wondered the exact same thing as you." —Sky [00:51]

2. About the Meta-Analysis

• Scale and Scope ([02:34]):
  • The meta-analysis distilled around 1,000 papers down to 18 studies involving 4.2 million participants.
  • Also briefly looked at Autism Spectrum Disorder (ASD), but nothing conclusive there.

"From those 18 studies, there are 4.2 million participants." —William [02:34]

3. The Bidirectional Link: Key Findings

• Correlation, Not Causation:
  • The research analyzed if hay fever leads to ADHD, or vice versa, but could not establish causality—only correlation.
  • Example: “ice cream in New York” analogy for confusion between correlation and causation.
• Statistical Findings ([03:35]):
  • Those with hay fever faced a 1.83-fold higher risk of developing ADHD.

"Compared to individuals without hay fever ... those with hay fever faced a 1.83 fold higher risk of developing ADHD, which. It literally just blew my mind." —Sky [03:35]

4. Possible Mechanisms and Confounding Factors

• Inflammation as a Bridge ([02:59]):
  • Chronic inflammation is noted in both ADHD and allergies, possibly connecting the two.
• Impact on Daily Life & Diagnosis ([05:54]):
  • Hay fever can lead to poor sleep, brain fog, and distraction—symptoms that can mimic or exacerbate ADHD.
  • Sleep disorders are a major confounding factor in ADHD diagnosis.

"When you can't breathe at night, it makes it much harder to sleep. And when you do sleep, you get worse sleep." —William [06:45]

• Threshold Effects ([08:46]):
  • Allergies may push individuals over the clinical threshold for ADHD diagnosis simply due to increased life impairments.

"...if you have something like hay fever, it's going to increase your detriments across multiple areas of your life. And so then you're starting to hit these thresholds much more likely..." —William [08:46]

5. Sociocultural and Environmental Context

• Urbanization & Climate Change ([07:18]):
  • Rapid urbanization (particularly in Asian countries) and climate change are increasing the prevalence and severity of hay fever.

6. Clinical and Practical Takeaways

• No Established Causation ([08:13]):
  • The team stresses that the findings highlight a correlation, not proof of cause and effect.
• Screening Advice:
  • Health professionals might consider monitoring for ADHD symptoms in individuals presenting with chronic hay fever.

"If somebody presents with hay fever, it might be worth telling them that they are also more likely now to present with the symptoms of ADHD." —Sky [08:33]

7. Curiosities and Future Research

• Why So Much Research? ([10:51]):
  • Sky speculates about the funding priorities behind so many studies on this topic.

"Why are so many papers spending...? There's many things that are related to ADHD that I wish people would study and they don't. And then suddenly this one has all these different papers..." —Sky [10:51]

• Possible Pharmaceutical Interest ([12:27]):
  • The hosts muse whether pharmaceutical companies might be interested in exploiting this link for treatment options.

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Notable Quotes & Memorable Moments

• “It turns out there's a ton of people who have wondered the exact same thing as you.” —Sky [00:51]
• “If you have allergies, you're more likely to have ADHD, and if you have ADHD, you're more likely to have allergies. Is wild.” —William [04:07]
• “Compared to individuals without hay fever ... those with hay fever faced a 1.83 fold higher risk of developing ADHD, which ... literally just blew my mind.” —Sky [03:35]
• “When you can't breathe at night, it makes it much harder to sleep. And when you do sleep, you get worse sleep.” —William [06:45]
• “...if you have something like hay fever, it's going to increase your detriments across multiple areas of your life. And so then you're starting to hit these thresholds much more likely...” —William [08:46]
• “Why are so many papers spending...? There's many things that are related to ADHD that I wish people would study and they don't.” —Sky [10:51]

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Timestamps for Important Segments

• 00:51 — Surprised by sheer volume of research connecting hay fever and ADHD
• 02:34 — Meta-analysis methodology and participant numbers
• 03:35 — Main statistical finding: 1.83-fold increased risk
• 05:54 — How hay fever influences sleep, focus, and functioning
• 07:18 — Environmental factors: urbanization, climate change
• 08:46 — Role of detriment thresholds in ADHD diagnosis
• 10:51 — Discussing research funding motivation

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Final Takeaways

• The episode strongly emphasizes that while there’s a statistically significant association between hay fever and ADHD, no causal relationship has been proven.
• For practitioners and laypeople alike: Monitor symptoms holistically—physical challenges like allergies may exacerbate cognitive or behavioral issues, blurring diagnostic lines.
• The hosts encourage continued curiosity and rigorous research, while also gently poking fun at the unpredictable interests of the scientific funding world.

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For more ADHD research and practical support, check out Sky’s podcast “ADHD Skills Lab” and her work at Unconventional Organization.

Transcript

[Sky Waterson]

Foreign.

[William Curb]

Welcome to Hacking your adhd. I'm your host, William Curb, and I have adhd. On this podcast, I dig into the tools, tactics, and best practices to help you work with your ADHD brain. Today, I'm joined by Sky Waterson for our Research Recap series. In this series, we take a look at a single research paper and dive into what the paper says and how it was conducted and try and find any practical takeaways. In this episode, we're going to be discussing a paper called Bidirectional association between Allergic Rhinitis and Attention Deficit Hyperactivity Disorder. Systematic review and meta analysis. And this is a comprehensive study looking at the relationship between allergic rhinitis, which is more commonly known as hay fever, and adhd. Oh, all right, let's get into it.

[Sky Waterson]

A couple of weeks ago, Will said to me, hey, should we look at some research to see if there's a connection between hay fever and adhd? And I went, I mean, we could see if there's something. And then my research assistant found me more papers on this topic connected than we have on almost all the other topics. It turns out there's a ton of people who have wondered the exact same thing as you.

[William Curb]

Yeah, I was very surprised because I was just. A lot of times when we're discussing topics, I'm just like, oh, is this something I've ever dealt with or heard about? I'll suggest that as a topic. And this was just like. I was like, man, my allergies are killing me. Wonder if there's a connection there. And it was one of those things where apparently. Yes.

[Sky Waterson]

Yeah. So we have a meta analysis on this, which basically means that so many people wanted to know this that they did a ton of different papers on it. And then somebody summarized all of those papers, particularly looking at the relationship between. I thought this was really interesting, not just ADHD being connected to hay fever, but also whether hay fever is connected to the development of adhd. And obviously, this is all correlation. None of this is causation. If you've ever seen the thing about ice cream in New York, you'll know that, you know, correlation and causation are not always the same thing. But I. I am very. It was really interesting. So they. They ended up only, however, including 18 different studies. So they started with, you know, looking at, like, about a thousand different studies and. And then worked it all the way down to just 18 different studies of. Of hay fever and ADHD.

[William Curb]

Although to mention, from those 18 studies, there are 4.2 million participants. They were these were studies looking at a large number of people.

[Sky Waterson]

That is very true. That is very true. Well done to them for actually finding that. Okay. They also did mean they did a little look at asd, which I thought was interesting, but they didn't find anything conclusive. But that was in the picture as a part of the conversation.

[William Curb]

Yeah, there was some. Some indications that there were connections between ASD and. And just for autism spectrum disorder. But yeah, again, nothing conclusive. So it is something that, hey, maybe in the future we'll see more on this, especially because, uh, one of these things that we're seeing, this crossover comes from inflammation, which is definitely something that plays into both ADHD and autism as well.

[Sky Waterson]

Yeah. And we have actually already looked at a paper on inflammation, so if you want to find it, you can search back through the history. Um. Cause we've talked about that.

[William Curb]

Yeah, we'll see. Maybe we'll do another one at some point.

[Sky Waterson]

Uh, yeah, well, maybe. I mean, it seems to be a thing. So they were looking at bi, the bidirectional relationship, and what they found was that compared to individuals without hay fever, I'm just calling it hay fever. Those with hay fever faced a 1.83 fold higher risk of developing ADHD, which. It literally just blew my mind. This whole paper is filled with just me writing question marks and exclamation points everywhere.

[William Curb]

Yeah, the. Yeah, I mean, as you said, with correlation, it's. We don't know which way it's going, but it is. Seeing that result is like, oh, yeah, if you have allergies, you're more likely to have adhd, and if you have adhd, you're more likely to have allergies. Is wild. Especially because. Well, and this is somewhat interesting in the US as we have, like in. We're having a spike in allergies because of climate change issues and how long trees are releasing pollen and how much they're releasing. But I should say that this isn't just Paul. Hay fever isn't just pollen. You also have mold and pet dander and all these other allergens that can cause this reaction, which is like the release of cytokines that I don't want to get too far into because I don't understand that science that well.

[Sky Waterson]

But in. In general, how does it make you feel for those of us who don't experience allergies?

[William Curb]

I'm actually doing better this year than I did last year because. But it's kind of like getting punched in the face where the. My sinuses just swell up and it hurts so much to just be. Last year I actually had to. I was reading my like, like page a day journal thing and it was like, oh, yeah, last year I got a prescription for steroid to help deal with the inflammation in my face because I could not do anything. It was just like I was in pain all day long from how much my sinuses were inflamed.

[Sky Waterson]

Yeah, yeah, no, and I think that's really important because it's not just like the sniffles or something that you might see. And I. Because, because this relates to the correlation and causation conversation. So one of the things they did mention was that sleep could be affected by, you know, having these kinds of allergies. Based on what you said, I think brain fog would probably be a factor as well. So there is a bit of a complicated conversation with relation to if you really did struggle with hay fever, you know, and then they gave you a thing about being distracted and struggling with, you know, focus. Well, we know that when we're diagnosing kids with adhd, one of the things that they're doing is they're doing a check of sleep disorders. And this. My. It's possible this is almost like a version of a sleep disorder.

[William Curb]

Yeah, absolutely. This it. When you can't breathe at night, it makes it much harder to sleep. And when you do sleep, you get worse sleep. Because so often you see with like sleep apnea curing or not curing, but treating the sleep apnea will basically make people who experience are experiencing the same, like ADHD symptoms have those just like disappear because it was all the lack of sleep and them getting used to it and just being like, this is how I'm so brain foggy and I'm just. This is how life is.

[Sky Waterson]

Yeah, exactly. And so when, when I'm working with clients, like we do do a baseline check, like, what is your sleep? Like, what is your, you know, what is your. Your exercise? Like, you know, all of those things that are likely to be. To be shifted if you're struggling with something like, like hay fever. So I guess, you know, one of the interesting things they mentioned was like, because they worked a lot with this study, had a lot of people from primarily Asian countries. They talked about this idea of rapid urbanization and maybe that was affecting, you know, the growing amount of people who are struggling with hay fever. And obviously you mentioned climate change. It feels like this paper is a bunch of arrows pointing to one another, but not necessarily a solid link.

[William Curb]

Yeah, 100. It's one of those things where

[Sky Waterson]

it's

[William Curb]

great preliminary research to be like, there is 100 link that we need to look into. And so I don't want anyone to come away from this being like, oh, either allergies cause ADHD or ADHD causes allergies. That's not something that we know yet, but it is something where we're like, oh, yeah, you're just more likely to have both.

[Sky Waterson]

Yeah, yeah. And so what they took away from it was if somebody presents with hay fever, it might be worth telling them that they are also more likely now to present with the symptoms of adhd.

[William Curb]

Yeah. And one thing I always find with these things, too, is the. Because of how we assess adhd, you know, it's like these thresholds of detriment in your life. And so if you have something like hay fever, it's going to increase your detriments across multiple areas of your life. And so then you're starting to hit these thresholds much more likely because, like, oh, yeah, if I'm going from, you know, forgetting my keys occasionally to chronically, I can't find anything that's going to be like, oh, yeah, that's. You're now clinically diagnosable with ADHD because you're hitting these thresholds.

[Sky Waterson]

Yeah, yeah, exactly, exactly. It does, but it's. It's an interesting conversation and it also, I guess it kind of adds to that piece on, you know, people are always interested in the connections, like, oh, I didn't realize this could be connected to adhd. And for those of you now, we have another one.

[William Curb]

Yeah, it's always something. And yeah, there's so many ways that it can work too, you know, because I was. While I don't want to talk about this, the individual science too heavily, like, you know, there's stuff with like, okay, we have how, like looking into how the. This chronic inflammation from hay fever can affect this. You know, you have stuff where it's like, oh, yeah, the blood brain barrier isn't as strong, and so you have more allergies from that kind of thing. And then you can have stuff with neurotransmitter metabolism being not as effective. So, oh, suddenly you go, oh, dopamine is not as effective with hay fever. Oh, that's. That feels like that's connected.

[Sky Waterson]

Yeah, yeah, yeah. 100%. 100%.

[William Curb]

So are there anything else you want to talk about with this paper, though?

[Sky Waterson]

I think I found it really interesting that I guess my biggest thing was like, why are so many papers spending? Because this costs money. You know, doing this paper costs Money. And there's many things that are related to ADHD that I wish people would study and they don't. And then suddenly this one has all of these different papers that did make me curious about, you know, I guess if I think about, like, there was no financing for this, this obviously came. Comes from, you know, I think it was the university science of Chinese medicine. I'm just curious about the reasoning behind so many papers about allergies and adhd, because it doesn't feel like a natural fit, at least to me.

[William Curb]

Yeah, I agree. As, like, as I said when we were doing the topic, I was like, oh, I'm just experiencing this. I wonder if there's a connection. And it is interesting that there is. It's not just me experiencing this, like, curiosity about this connection. Enough so that there's a lot of research going into it and. But not a lot of conclusive research yet.

[Sky Waterson]

Yeah. And it does make me wonder if there is a universe and I don't know. So please don't hold me to this. If there is a universe where people are going, like, what would happen if we found a really good way to deal with hay fever? Like, you know, they're both medications based, you know, support, like, what does that look like? I wonder if there's something being built because they're investing a lot of money in these papers on this topic.

[William Curb]

Yeah, I could definitely see a potential for, you know, drug companies trying to be like, oh, yeah, this is something we can definitely make a dime off of.

[Sky Waterson]

Yeah. And maybe not. Maybe they just really want to help us out and give us that research.

[William Curb]

Let's hope it's that one.

[Sky Waterson]

Hello, everyone. If you have enjoyed listening to this episode, then you might like to listen to my podcast, the ADHD Skills Lab, where we go and deep dive into more of the research. And also we focus on ADHD support for business owners. Whether you're aspiring or you have your own company, and if you have your own company and you wish that you had somebody who would just build these systems for you so you could stop figuring out what to do all the time. Well, that's what we do. We are mentor and operator together. So if you want to learn a little bit more about that, you can find me at Unconventional Organization. Thanks for listening.