The Week Before Was Always Hard. You Just Had a Date for It.
Body · The Reading Room, Vol. 39 · 8 min read · Why the pattern lost its edges, what the research points at instead of hormone levels, and where the evidence genuinely runs out
Based on the published research of Jennifer L. Gordon, PhD — Associate Professor, Department of Psychology, University of Regina, whose lab studies reproductive hormones and mood. Faculty profile
PMS getting worse in perimenopause is an experience with a partial explanation and an unfinished literature. What the research points at is change itself, rather than the level of anything.
For twenty-five years you knew the week. Day twenty-two onward, short with everybody, weepy at an advert, and then the period arrived and the weather cleared and you could look back and see what it had been.
What is happening now has no week attached to it. It arrives, it goes, sometimes there is a period after it and sometimes there is not, and by the time you have worked out what it was, it has moved.
Which is worse in a specific way that is hard to explain to anyone. The bad days are not obviously more severe. What has gone is the ability to file them.
The short answer: what drives premenstrual mood symptoms appears to be hormonal change rather than hormonal level. A 2021 review in Current Psychiatry Reports summarises evidence that these symptoms are triggered by change in ovarian steroid levels and not by continuous stable levels.¹ Perimenopause is, by definition, the period of maximum change. The Study of Women’s Health Across the Nation makes the same point about mood in general: symptoms are worse when estrogen levels vary more widely and progesterone is no longer being produced.² Nothing about your tolerance has fallen. The input became irregular.
The skim version
- Premenstrual mood symptoms track change in ovarian hormones rather than stable levels of them.¹
- SWAN reports mood symptoms worsen when estrogen varies more widely and progesterone is no longer produced.²
- An important subset of women reacts specifically to hormone elevations in perimenopause, not only to withdrawal.¹
- Women with a history of premenstrual disorders may be more reactive at either end: elevation early, withdrawal late.¹
- The review states plainly that more research is needed to clarify how premenstrual mood symptoms behave across the transition.¹
Is PMS getting worse in perimenopause, or does it only feel that way?
The honest answer is that the experience is widely reported and the trajectory has not been established, which is not the same as it being imaginary.
This is a place where it is worth being precise rather than reassuring. The 2021 review concludes that additional research is needed to clarify the trajectory of premenstrual mood symptoms across the menopause transition.¹ Nobody has yet mapped, at scale, whether these symptoms reliably intensify, change shape, or simply become harder to attribute.
What is better established is the mechanism underneath them. The symptoms respond to change in ovarian steroids rather than to how much of any hormone is present.¹ That single fact explains a great deal of what makes this phase confusing, because during perimenopause the change is no longer arriving on a schedule.
SWAN’s own summary of mood across the transition points the same way, noting that women are more vulnerable especially in the run-up to the final period, and that symptoms are worse when estrogen levels vary more widely.² Variation is the operative word in both sources.
Why the loss of the pattern is its own problem
Because a predicted bad week is a manageable bad week, and an unpredicted one gets read as evidence about you.
Consider what the old pattern actually did for you. It gave you a warning, so you could avoid scheduling the difficult conversation. It gave you an explanation, so a sharp comment on the Tuesday was a hormonal week rather than a personality. And it gave you an end date, so you knew it would lift.
All three of those are gone at once. That is a genuine loss of function and it has nothing to do with the severity of the symptoms themselves. It is the difference between weather you can forecast and weather you cannot.
There is a second complication, and the review is specific about it. It describes an important subset of women who experience depressive mood in response to perimenopausal elevations in ovarian hormones, not only to the drops.¹ In practice that means a difficult stretch can arrive at what would once have been the good half of the month, which removes the last usable rule of thumb you had.
What the research found
The most useful finding in this area is a negative one. Premenstrual mood symptoms are not explained by having too little of a hormone, which is why measuring a level on a single day so often tells you nothing. The evidence points at sensitivity to change.¹ The review also notes that women with a history of premenstrual disorders may be reactive at both ends of the transition: to hormone elevation in early perimenopause, and to withdrawal later on.¹
The limitation, stated by the authors: the trajectory of premenstrual mood symptoms through the menopause transition has not been clarified and needs more research.¹ So the mechanism has support and the specific claim that PMS predictably worsens does not yet. SWAN adds a further complication worth knowing: mood symptoms in this phase can come from hot flashes and broken sleep as much as from hormones directly, and a first episode of depression at this age is more strongly linked to stressful life events and a history of anxiety than to menopause itself.² Several things are happening at once and the research cannot yet tell you their relative sizes.
If the difficult weeks are landing on a life with no slack in it, the slack is the part you can actually change. The Quiet Audit is a private ten-minute pass through where the week goes. Start here.
What the pattern used to do, and what replaces it
| The old cycle | Now | |
|---|---|---|
| Warning | A date you could see coming | None |
| Explanation | It is that week | I am becoming difficult |
| End date | Known, within days | Unknown, which changes how it feels |
| What you tell people | Something short and true | Nothing, because you cannot name it |
The second row is where most of the private damage is done. An unexplained bad week gets filed as character, and character is not something you can wait out. The anger version of this arrives with the same missing label, and the anxiety version has a mechanism worth reading alongside it.
What to do while the science is unfinished
Rebuild the forecast yourself, because nobody else can do it for you.
The old pattern was information you got free, from your body, on a schedule. It has stopped being free. It has not stopped being obtainable, and reconstructing it is the single most useful thing available while the research catches up.
Two months of one line a day does it. A date, a number from one to five for mood, and whether you bled. Nothing else, no journaling, no analysis at the time. Sixty lines takes about four seconds a day.
What comes out of it is worth having in two directions. Some women find the cluster is still there, just at eighteen or forty-one day intervals rather than twenty-eight, which restores the warning and the end date at a stroke. Others find no cycle at all, which is also an answer, and points at sleep, hot flashes or load rather than at the cycle.
And it changes what happens in an appointment. Two months of dated lines is data. Saying you think your PMS has got worse is an impression, and impressions get seven minutes and sympathy. The question of which of these two things you are actually dealing with is worth reading before you go.
The source for this piece
Jennifer L. Gordon, PhD
Associate Professor in the Department of Psychology at the University of Regina, whose research examines how sensitivity to hormonal change, rather than hormone levels themselves, drives mood symptoms across the reproductive lifespan.
What we read: Sander, B., & Gordon, J. L., Current Psychiatry Reports (2021).¹
Where to follow her work: Faculty profile
Who else has measured this
The hormone-sensitivity model reviewed here has a close counterpart in the clinical study of premenstrual dysphoric disorder.
Tory Eisenlohr-Moul, PhD (Faculty · Scholar · ResearchGate · Lab site), Associate Professor of Psychiatry at the University of Illinois Chicago, directs a research programme establishing that a subset of women are neurobiologically sensitive to normal hormone changes themselves, rather than to any abnormal hormone level — closely paralleling the change-not-level mechanism this piece describes.
Two independent research programmes, one focused on the menopause transition and one on the menstrual cycle, converging on the same underlying idea: sensitivity to change, not the level of anything, is what drives the symptom.
What has gone is the ability to file them.
Questions worth having an answer to
Can a blood test tell me what is happening?
Usually not for this. If the symptoms track change rather than level, a single reading captures one point on a moving line.¹ Hormone tests have their uses in the transition, and settling the mood question is generally not one of them.
I had bad PMS in my twenties. Does that predict this?
It may be relevant. The review notes that women with a history of premenstrual disorders warrant particular attention, with some showing heightened sensitivity to hormone elevation in early perimenopause and others to withdrawal later on.¹ It is worth telling a clinician about, and it is not a forecast.
How do I know if this is depression rather than the cycle?
The rough distinction is duration and lift. Cycle-linked symptoms come and go and clear completely in between. What is worth taking seriously is low mood most of the day for weeks that does not lift, loss of interest in things you normally like, or a settled change in sleep or appetite. That belongs with a clinician.
Will it stop when my periods stop?
For symptoms genuinely driven by cyclical change, the logic says yes, once the changing stops. SWAN describes the greatest vulnerability as sitting just before the final period.² What that timeline is for any individual woman is not something the current evidence can tell you.
The one move
Start a two month line-a-day record tonight: the date, mood out of five, and whether you bled. No commentary. In two months you will either have your pattern back or you will know it is not the cycle, and both are worth having.
If the difficult weeks are only unmanageable because there is no room in the week to begin with, that is the finding. The Quiet Audit is a private pass through what your week is actually spending. Start here.
On the researcher. Jennifer Gordon is a clinical psychologist studying reproductive hormones and mood; the review cited here states plainly that the trajectory of these symptoms across the transition has not been clarified, and this article does not go further than that.
Sourcing, disclosure and disclaimers
This is not medical advice. Blue Leaf Journal publishes general information for a general readership. Nothing here is a diagnosis, a treatment recommendation, or a substitute for care from a clinician who knows your history.
We are not clinicians. Blue Leaf Journal is an independent publication. We read published research and translate it. The findings belong to the researchers and institutions named and linked above; the plain-English rendering is ours, and so is any error in it.
No affiliation and no endorsement. Blue Leaf Journal is not affiliated with Jennifer L. Gordon, Tory Eisenlohr-Moul, the University of Regina or the University of Illinois Chicago. None of them has reviewed, approved or endorsed this article, and none of them is responsible for it. They are cited because their published work is the evidence for what it says.
No commercial relationship. Nobody named above paid for or was paid for this coverage. There are no affiliate links, no sponsored placements and no gifted products in this article.
How this was checked. Every figure above is drawn from the primary papers, each linked in the references, and can be verified there. Sources were checked on 6 September 2026. If you find something we have got wrong, write to norawhitfield@blueleafjournal.com and we will correct it and say that we did.
References
1. Sander, B., & Gordon, J. L. (2021). Premenstrual Mood Symptoms in the Perimenopause. Current Psychiatry Reports. Read the review
2. Study of Women’s Health Across the Nation. SWAN Fact Sheets, 2023 edition, depression and mood across the menopause transition. Read the fact sheets
Nora Whitfield writes the Body desk at Blue Leaf Journal, where the working rule is that a mechanism you can name is easier to live with than one you cannot. She reads the limitations section before the conclusion, and passes on what she finds there.
Written by Nora Whitfield for Blue Leaf Journal. Updated: 5 September 2026.
