For a large fraction of people who menstruate, mood is not a free variable. It rises and falls partly on a roughly monthly schedule, and for some that schedule produces a few uncomfortable days, while for a smaller group it produces something disabling. The difference between those two — ordinary premenstrual change and the disorder called PMDD — turns almost entirely on one thing that is impossible to judge from memory: timing.
Which makes this one of the cleanest cases for prospective mood tracking in the whole field. The chart is not a nice-to-have. The chart is the evidence.
PMS and PMDD are different in degree and in kind
Premenstrual syndrome is common and mostly mild: bloating, irritability, tender breasts, a dip in mood in the days before bleeding, gone once it arrives. Most people who menstruate recognise some version of it.
Premenstrual dysphoric disorder is a different category — added to the main text of DSM-5 in 2013 after the review by Epperson and colleagues laid out the evidence that it met the bar for a distinct diagnosis.1 PMDD means marked mood symptoms — depression, anxiety, irritability, sudden tearfulness, a sense of being overwhelmed — in the luteal phase before menstruation, severe enough to interfere with work or relationships, that reliably remit within a few days of the period starting. It affects an estimated 2-5% of menstruating people. The symptoms overlap with PMS; the severity, and the functional damage, do not.
What makes PMDD biologically interesting is that it is not caused by abnormal hormones. Schmidt and colleagues' elegant NEJM experiment showed that women with PMDD have normal hormone levels — but blocking and then reintroducing those normal hormones triggered symptoms in them and not in controls.4 It is an abnormal sensitivity to ordinary hormonal change, not abnormal hormones. The trigger is normal; the response is not.
The diagnosis is a timing claim
Because the symptoms themselves — low mood, anxiety, irritability — are not specific, PMDD cannot be diagnosed from a symptom list. It is diagnosed from a pattern: symptoms that cluster after ovulation and lift after menstruation, confirmed by daily ratings across at least two consecutive cycles. DSM-5 builds the prospective record into the criteria. No confirmed on-off pattern, no PMDD.
The reason the requirement is so strict is that memory gets this specific question wrong, in a predictable direction. When researchers compare what people remember about their premenstrual symptoms with what they recorded daily at the time, the retrospective reports frequently fail to confirm. People attribute a bad stretch to their cycle that, charted day by day, turns out to run all month — or to track stress, or sleep, rather than phase. Eisenlohr-Moul and colleagues built the C-PASS scoring system precisely to apply consistent rules to those daily charts, because eyeballing them is also unreliable.2
This is not a bureaucratic hurdle. A mood problem that merely coincides with the cycle — an underlying depression, an anxiety disorder, a thyroid condition — needs different treatment from one that is driven by it. The chart is what tells those apart, and getting it wrong sends someone toward the wrong help.
What to actually track
The validated instrument is the Daily Record of Severity of Problems: a short daily questionnaire rating the core symptoms and their impact on functioning, designed to be scored across cycles.3 A general mood tracker is not the DRSP and should not claim to be. But the load-bearing signal — daily mood ratings aligned to cycle dates — is exactly what a daily mood log captures.
In practice, in Colors: log mood daily as usual, note the period start each cycle, and after two cycles read the series against those dates. The question is binary and visual — do the dark days bunch in the back half of the cycle and clear after bleeding starts, or are they scattered? Tag the prominent symptom (irritable, anxious, tearful) and a clinician gets not just timing but texture. Two months of that is a far better artifact to bring to an appointment than "I think my mood follows my cycle," and it is the same artifact the diagnosis is built on.
Even without a diagnosis, the chart helps
Most people tracking this will not have PMDD; they will have a cycle-linked dip worth understanding rather than diagnosing. The chart still pays off, through anticipation. A hard day reads differently when you can place it: day 25, this is the predictable stretch, it lifts when the period starts is a fundamentally less frightening experience than the same low mood arriving as a mystery. Knowing a state is phase-related and time-limited is, by itself, a mild intervention — it pre-empts the catastrophising that treats a bad Tuesday as evidence about the rest of life.
It also sharpens the triggers vs factors picture: cycle phase is a slow, recurring factor, and once it is visible on the chart you stop misattributing its effects to whatever acute trigger happened to land that day. The argument at dinner did not ruin the week; it landed in a week that was already tilted.
This article is not medical advice, and PMDD in particular is treatable — with approaches ranging from SSRIs to hormonal options — so a confirmed pattern is a reason to see a clinician, chart in hand, not to self-manage indefinitely. The tracking is what makes that visit productive.
Frequently asked questions
What is the difference between PMS and PMDD?
PMS (premenstrual syndrome) covers the common, mild-to-moderate physical and emotional changes in the days before a period — bloating, irritability, low mood — that resolve once it starts. PMDD (premenstrual dysphoric disorder) is a distinct, severe condition added to DSM-5 in 2013: marked mood symptoms (depression, anxiety, irritability, or sudden tearfulness) in the week or so before menstruation, severe enough to disrupt work or relationships, that reliably lift within a few days of bleeding starting. PMDD affects an estimated 2-5% of menstruating people; milder PMS is far more common.
How is PMDD diagnosed?
By timing, established prospectively. DSM-5 requires symptoms confirmed by daily ratings across at least two consecutive cycles — not memory. The defining feature is the pattern: symptoms cluster in the luteal phase (after ovulation, before the period) and remit shortly after menstruation begins. Without that confirmed on-off pattern, it isn't PMDD, which is why a couple of months of daily tracking is part of the diagnosis itself, not just preparation for it.
Why can't I just diagnose it from memory?
Because memory is unreliable for exactly this, and the error has a known direction. Studies comparing remembered with prospectively recorded symptoms find that retrospective reports often don't hold up — people attribute distress to the cycle that, recorded daily, turns out to be present all month or unrelated to phase. A condition that runs alongside the cycle but isn't driven by it (depression, anxiety, a thyroid issue) needs different treatment, so the prospective chart isn't bureaucratic — it changes what helps.
What is the DRSP?
The Daily Record of Severity of Problems — the validated daily questionnaire most used for this. Each day you rate the core symptoms (mood, irritability, physical symptoms, functioning) on a short scale. Over two cycles, the chart shows whether symptoms genuinely track the luteal phase. A general mood tracker isn't the DRSP, but daily mood entries aligned to cycle dates capture the same essential signal — the timing — and give a clinician something real to read.
Can mood tracking help with cycle-related mood changes?
Directly, in two ways. First, it produces the prospective record a diagnosis requires, turning 'I think my mood follows my cycle' into a chart that either shows the pattern or doesn't. Second, even short of diagnosis, knowing a hard stretch is phase-related and time-limited reframes it: the same low day reads differently when you can see it is day 25 and lifts predictably. Anticipation is itself a mild intervention.
Not medical advice
This article is for informational and educational purposes only. It does not constitute medical advice and should not replace consultation with a licensed mental health professional. If you are in crisis, please contact emergency services in your country immediately.
Crisis lines: US — 988 Suicide & Crisis Lifeline · UK / Ireland — Samaritans 116 123 · EU — Befrienders Worldwide
Last reviewed: May 2026.
References
- Epperson, C. N., Steiner, M., Hartlage, S. A., et al. (2012). Premenstrual dysphoric disorder: Evidence for a new category for DSM-5. American Journal of Psychiatry, 169(5), 465–475. doi:10.1176/appi.ajp.2012.11081302
- Eisenlohr-Moul, T. A., Girdler, S. S., Schmalenberger, K. M., et al. (2017). Toward the reliable diagnosis of DSM-5 premenstrual dysphoric disorder: The Carolina Premenstrual Assessment Scoring System (C-PASS). American Journal of Psychiatry, 174(1), 51–59. doi:10.1176/appi.ajp.2016.15121510
- Endicott, J., Nee, J., & Harrison, W. (2006). Daily Record of Severity of Problems (DRSP): Reliability and validity. Archives of Women's Mental Health, 9(1), 41–49. doi:10.1007/s00737-005-0103-y
- Schmidt, P. J., Nieman, L. K., Danaceau, M. A., Adams, L. F., & Rubinow, D. R. (1998). Differential behavioral effects of gonadal steroids in women with and in those without premenstrual syndrome. New England Journal of Medicine, 338(4), 209–216. doi:10.1056/NEJM199801223380401