Link to prespecified protocol of this research: https://www.crd.york.ac.uk/PROSPERO/view/CRD420261436583
We're Doing Something No One Has Done Before
Slowly, over the last five years, studies are emerging that confirm what many in this community already suspected: there are significantly higher rates of PMDD in women with ADHD, and vice versa.
Each study points the same way, but nobody's pulled them together to quantify just how much higher that likelihood really is. The findings vary, and sit scattered across separate papers, different populations, different methods, with no one bringing the data together into a single, reliable answer.
At DITTO, we're conducting the first ever systematic review and meta-analysis of the co-occurrence of ADHD and PMDD.
Systematic reviews and meta-analyses sit at the top of the evidence hierarchy. They're what turns "this might be the case" into "this is real", not an artifact of a few small studies.
This review will transform what's currently seen as an emerging signal on the PMDD-ADHD connection into robust, quantified evidence, the kind that raises awareness, changes clinical practice, and shapes research agendas.
Because research locked in a journal doesn't change anyone's life. Shouting it from the rooftops does.
The Study that Set the Bar
The most striking recent evidence comes from a 2025 study in the British Journal of Psychiatry, which looked at 715 people assigned female at birth, aged 18 to 34 (1).
This study showed:
◉ Those with symptom-based ADHD (met criteria, whether or not formally diagnosed):
41.1% had PMDD
◉ Those with self reported clinical ADHD diagnosis:
31.4% had PMDD
◉ Controls (no ADHD):
9.8% had PMDD
That works out to roughly 3 to 4-fold higher rates of PMDD among people with ADHD.
It Goes the Other Way
Other studies have measured the link from the opposite direction, starting with PMDD and looking for ADHD. This bi-direction strengthens the validity of this connection.
A 2024 study out of Taiwan, published in the Journal of Women's Health, tracked 58 women with PMDD and 50 controls. Their data showed that over 1 in 4 women with PMDD also had ADHD, versus roughly 1 in 8 without PMDD - a little over a 2-fold difference (2).
Critically, the authors' also found that the two conditions compound each other across the cycle, not just co-occur.
Beyond Prevalence: The Neurobiology and Life-Stage Exacerbations
We're not stopping at prevalence. The neurobiological basis of the ADHD-PMDD link has never been comprehensively reviewed either, so we'll also synthesise the mechanisms researchers have proposed to explain it, and look for where they may compound or line up.
ADHD and PMDD don't just disrupt lives premenstrually. They can flare during other reproductive transitions too, postpartum and perimenopause among them, because both conditions are influenced by hormonal change. We'll be reviewing that evidence as well, and expect to be highlighting gaps where more research is needed.
What is could change for you
This review takes the PMDD-ADHD connection out of 'maybe' territory for good. What'll be left is something people can actually use.
For the individuals with lived-experience: Knowing that this co-occurrence is real, and understanding why it happens, can help you recognise patterns in yourself. That's biology that deserves support, and now you can name it. This review will also give you something concrete to hold onto: a number you can point to, this many times more likely, backed by the highest tier of evidence available. It's the kind of proof you can print out, bring into a doctor's office, and use to advocate for yourself while pursuing a diagnosis, instead of being talked out of what you know to be true.
For clinical practice: It means raising awareness among providers who are largely unaware this connection even exists, and giving them a reason to screen for one condition when a patient presents with the other. Right now, a clinician treating ADHD has no strong evidence-based prompt from their guidance to ask about premenstrual symptoms, and a clinician treating PMDD may not have what they feel is a solid reason to consider ADHD. Most don't know how often the two show up together. Quantified risk changes that. It makes it worth asking about every time. It also opens the door to treating the two together rather than separately.
For research agendas: This review will name what studies need to happen next, and where the gaps are. The neurobiology, the risk factors, the hormonal sensitivity across life stages - it all needs large, well-designed research trials. There’s also the question of treatment and holistic approaches: how interventions that target one condition might not work if the other is present, what’s worth testing to target both, how dosing might need to shift across the menstrual cycle, or the support that can be put in place during life-stages when it’s known the symptoms may be exacerbated. We'll turn these gaps into recommendations for future research.
We're positioned to do this in a way almost no one else is. We're not just researchers looking at data from the outside, we have a community of 300,000 people who tell us what they're experiencing and what they need, every day. Our recommendations will be grounded in what actually matters to the people living with both conditions, not just what's convenient to study.
For policy: Workplace accommodations and disability recognition depend on there being solid evidence behind them, and right now that evidence doesn't exist for this specific overlap. Those who navigate ADHD and PMDD face a real barrier that's invisible to the systems meant to support them, because those systems have nothing to point to. This review won't fix that on its own, but it's the missing evidence base that future policy change would need to lean on.
What actually is the process of a systematic review and meta-analysis?
A systematic review is "systematic" because we use specialised training and tools to predefine a strict set of rules for finding, filtering, evaluating and analysing evidence. A systematic review holds all the existing studies up at once, checks it for quality, and asks what the whole picture says once you account for strengths and flaws. Combine everything together, and you get a far more trustworthy estimate than any single study could give you on its own.
Our rules: we only include studies of people who've started menstruating, with PMDD and ADHD measured through clinical diagnosis, clinician-defined criteria, or validated questionnaires. We exclude anyone whose hormonal picture would distort the comparison, like pregnancy or menopause.
We're also analysing the connection from both directions (a bidirectional association), and that's deliberate. If it holds up regardless of which condition you start from, that's a much stronger signal.
Studies with a control group are included in one statistical analysis to let us say the co-occurrence rate is elevated rather than just reporting a number in isolation; studies without a control are still included, just analysed separately, so they inform the picture too. We are being as thorough as the question deserves.
Two independent reviewers, Alice and Marleigh, DITTO scientists, search the world's largest academic databases against those criteria, casting a wide net over every study that could hold relevant data. We sift through thousands of studies, keep the ones that fit, then extract the data and assess each study's quality: risk of bias, sample size, diagnostic criteria, and more.
The meta-analysis happens when enough studies collected and reported data in similar ways. We pool it into one combined estimate, more precise than any single study, turning scattered co-occurrence numbers into one figure the field can stand behind.
We're Making a Promise
We're proud to be doing this, and impatient to get it into your hands. PMDD on its own, and ADHD in women on its own, have been dismissed or overlooked by much of the medical field for far too long, let alone the link between them. To us, that link has been hiding in plain sight, spread thin across a handful of studies, waiting for someone to bring it together. We're that someone.
When it's done, it won't sit behind a paywall or get buried in jargon. We will fund this research paper to be open access, we’ll present it at conferences far and wide, and we'll break it down plainly and honestly, so it’s accessible for everyone who needs it. Stay tuned.
We'll continue publishing research in this area, because moving this historically ignored field forward isn't a one-off - it's a long-term commitment.
References
1. Broughton T, Lambert E, Wertz J, Agnew-Blais J. Increased risk of provisional premenstrual dysphoric disorder (PMDD) among females with attention-deficit hyperactivity disorder (ADHD): cross-sectional survey study. British Journal of Psychiatry. 2025;226(6):410–417. doi:10.1192/bjp.2025.104
2. Lin PC, Long CY, Ko CH, Yen JY. Comorbid attention deficit hyperactivity disorder in women with premenstrual dysphoric disorder. J Womens Health (Larchmt). 2024;33(9):1267-1275. doi:10.1089/jwh.2023.0907