What PMDD is
Premenstrual dysphoric disorder, PMDD for short, is a severe form of premenstrual symptoms. The symptoms are confined to the days before the period. Since 2013 PMDD has been recognised as a psychiatric diagnosis in its own right.
How common it is
A 2024 meta-analysis with just over 50,000 participants arrives at 3.2% when the diagnosis was confirmed and 7.7% for a provisional diagnosis. In studies from the general population with a confirmed diagnosis, it was 1.6%.
Why writing it down matters
The diagnosis is only confirmed once symptoms have been recorded continuously over two cycles; before that it counts as provisional. The symptom choice in Rhythmus is too small for this assessment; ask at the practice for a diary that covers the diagnostic criteria.
The diary clarifies something else too. For some people, the symptoms of an existing condition such as depression, panic disorder or an eating disorder get worse before the period but don't go away afterwards. A 2022 systematic review found clear evidence of this for several mental health conditions. That is not PMDD, and it is assessed differently.
What the studies say about treatment
A 2024 Cochrane review of 34 studies concludes that certain antidepressants, known as SSRIs, probably reduce premenstrual symptoms – with moderate-certainty evidence. Taken continuously, they worked better in the studies than when taken only in the second half of the cycle. Side effects such as nausea, sleep problems and reduced interest in sex were more common. 68% of the studies were funded by pharmaceutical companies; the authors explicitly name this as a reason for caution.
Whether and how to treat it is something to discuss with your doctor or psychotherapist.
When it gets dark
According to a 2026 review, people with PMDD have an increased risk of suicidal thoughts. That is a reason to take the days before your period seriously if they feel like this – and to talk about it.