Premenstrual Syndrome

Somatic and psychological symptoms during the luteal phase, remitting within a few days of menstruation and absent in the follicular phase. Symptoms typically start 1 to 2 weeks before menstruation.

Up to 80% of people who menstruate experience some form of premenstrual syndrome. Symptoms are moderately severe in 20 to 40% and disabling in 2 to 9%. Premenstrual dysphoric disorder (PMDD) is the severe end of that spectrum and has been an official psychiatric diagnosis since 2013; recent prevalence estimates put it at 3% to 8%.

A 2024 pooled analysis of 44 studies found PMDD prevalence of 7.7% on provisional (retrospective) diagnosis but only 3.2% when confirmed with prospective symptom scoring — a useful reminder of why charting matters.

Circulating oestrogen and progesterone levels are normal in premenstrual syndrome. The leading hypothesis is an increased sensitivity to normal luteal-phase hormone fluctuation, mediated through serotonergic and GABAergic pathways.

History

Psychological: irritability, mood swings, anxiety, depression, general dysphoria, a sense of loss of control or inability to cope.

Physical: bloating, headaches, breast discomfort. Chronic conditions such as epilepsy, migraine and asthma may be exacerbated premenstrually.

Anger and irritability usually cause the most distress and tend to appear slightly earlier than the others. Intensity typically builds from about six days before menses and peaks in the two days before bleeding starts.

Diagnosis

No diagnostic test exists for either condition. Prospective daily charting of symptoms over two menstrual cycles is highly desirable, and DSM-5 requires it for a confirmed PMDD diagnosis — though a provisional diagnosis can be made first.

Charting also separates PMS from a premenstrual exacerbation of underlying depression or anxiety. The diagnosis is supported if symptoms occur in the luteal phase, improve at menstruation, and are absent for at least one week per cycle.

Validated instruments include the Daily Record of Severity of Problems (the most widely used and best validated), the Premenstrual Symptom Screening Tool, and the Calendar of Premenstrual Experiences.

Exclude other causes, particularly thyroid disorders and, where relevant, menopause.

Management

Non-pharmacological

Lifestyle change, exercise, relaxation techniques and CBT all help, and may be enough on their own.

• Exercise — ACOG recommends routine moderate exercise, though the evidence is not from randomised trials.
• CBT — a meta-analysis found it about as effective as antidepressant medication for premenstrual symptoms.
• Calcium — 1,200 mg daily significantly reduced symptom severity in PMDD in the studies ACOG relies on. Note that eTG regards the evidence for calcium and other complementary treatments (evening primrose oil, chasteberry) as limited.

Pharmacological

• COCP — aims to suppress ovulation. Extended or continuous use, or a shorter hormone-free interval, controls mood symptoms better than standard cyclical dosing, since symptoms often return during hormone-free days. Drospirenone-containing pills may help PMDD particularly, through their anti-aldosterone and anti-androgenic effects. Progestogens used alone are ineffective and may even aggravate symptoms.
• SSRIs and SNRIs — effective for the physical and psychological symptoms alike. Fluoxetine and sertraline are the usual choices; no one agent is known to be better than another, and switching to a different SSRI is reasonable if the first does not work. Onset is faster than in major depression.
• SSRI dosing — continuous, or luteal-phase only (the two weeks before menstruation). Luteal-phase dosing has fewer adverse effects and is often more acceptable, but continuous dosing is preferred where the picture is a premenstrual exacerbation of comorbid depression or anxiety. Nausea is the commonest adverse effect and usually settles within days; reduced libido and anorgasmia resolve in drug-free intervals. Not PBS-subsidised unless there is concurrent anxiety or depression.
• Review after one cycle, and reconsider the need for treatment after 12 months — symptoms usually recur on stopping, and long-term treatment is often needed.
• Spironolactone may relieve the physical symptoms (bloating, swelling, breast discomfort) and psychological symptoms, though the evidence is limited. It requires reliable contraception because of the risk of defective virilisation of a male fetus.

Referral

Consider specialist referral if symptoms are severe (for example, suicidal thoughts) or do not respond to other therapies. Specialist options include GnRH agonists, which induce a medical menopause and so are given with oestrogen and progesterone add-back to limit hot flushes and bone loss.