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Case 24.7 – Pre-Menstrual Syndrome & Dysphoric Disorder

Category: Medicine | Discipline: Obstetrics & Gynaecology | Setting: GP Surgery

Case

Mrs. Hannah Roberts, a 30-year-old office manager, presents to her GP with severe premenstrual symptoms that have progressively worsened over the past 2 years. She reports that for 7-10 days before each period, she experiences intense mood swings, irritability, anxiety, and low mood. She describes feeling "out of control" and has had several arguments with her husband during this time. She also experiences breast tenderness, bloating, and food cravings (especially chocolate and carbohydrates).

Her symptoms begin around day 18-21 of her cycle (luteal phase) and resolve within 1-2 days of her period starting. She feels "completely normal" for the first 2 weeks of her cycle (follicular phase). The severity of her symptoms has led to her taking sick days from work and has strained her relationship with her husband.

Hannah has regular 28-day menstrual cycles with moderate flow lasting 5 days. She denies heavy bleeding, intermenstrual bleeding, or pelvic pain outside of the premenstrual phase. She has no history of depression or anxiety disorders, though she did experience mild postnatal depression after the birth of her second child 3 years ago (resolved with counselling). She is not currently using contraception as she and her husband have completed their family (2 children aged 3 and 5).

Past medical history is unremarkable. She takes no regular medications. She drinks 5-10 units of alcohol per week and is a non-smoker. There is a family history of depression (mother).

On Examination:

Symptom Diary (2 Cycles)

Hannah was asked to complete a prospective symptom diary over 2 menstrual cycles, rating symptoms daily (0-3 scale: 0=none, 3=severe):

Follicular Phase (Days 1-14): Luteal Phase (Days 18-28):

Clear luteal phase pattern with symptom-free interval in follicular phase → Confirms cyclical premenstrual disorder

Questions

Question 1: What is the difference between PMS and PMDD, and how are they diagnosed?

Definitions:

Premenstrual Syndrome (PMS):

  • Cyclical physical, psychological, and behavioural symptoms occurring in the luteal phase (after ovulation, days 14-28) that resolve shortly after menstruation starts
  • Affects 20-40% of menstruating women
  • Symptoms cause mild-moderate impairment in daily functioning

Premenstrual Dysphoric Disorder (PMDD):

  • Severe form of PMS with predominantly mood/psychological symptoms that cause significant functional impairment
  • Affects 3-8% of menstruating women
  • Recognized as a psychiatric disorder in DSM-5
  • Symptoms severely impact work, relationships, and quality of life

Common Symptoms:

Psychological/Mood symptoms:

  • Mood swings, irritability, anger
  • Depression, low mood, crying
  • Anxiety, tension, feeling "on edge"
  • Difficulty concentrating, confusion
  • Feeling overwhelmed or out of control
  • Social withdrawal, reduced interest in activities

Physical symptoms:

  • Breast tenderness (mastalgia)
  • Bloating, weight gain (fluid retention)
  • Headaches, joint/muscle pain
  • Fatigue, lethargy
  • Food cravings (especially sweet/salty foods)
  • Sleep disturbance (insomnia or hypersomnia)

Diagnostic Criteria (Both PMS and PMDD):

1. Timing - Essential Features:

  • Symptoms occur in luteal phase (after ovulation, typically days 14-28 of cycle)
  • Resolve within days of menstruation starting (follicular phase)
  • Symptom-free interval in follicular phase (days 1-14) - this is KEY for diagnosis
  • Pattern consistent across ≥2 consecutive menstrual cycles

2. Symptom Severity:

  • PMS: Mild-moderate impairment in daily activities, work, relationships
  • PMDD: Severe impairment - inability to work, significant relationship strain, suicidal ideation (rare but reported)

3. Exclusion of Other Causes:

  • Not due to medications, substance use, or another medical condition
  • Not an exacerbation of underlying psychiatric disorder (e.g., depression, anxiety, bipolar disorder)
    • Key difference: PMS/PMDD patients have symptom-free follicular phase, while those with depression/anxiety have continuous symptoms

Diagnosis - Prospective Symptom Diary (ESSENTIAL):

  • Daily symptom diary for ≥2 consecutive menstrual cycles (mandatory for diagnosis)
  • Rate symptoms daily (e.g., 0-3 scale: 0=none, 3=severe)
  • Record: Mood symptoms (irritability, anxiety, low mood), physical symptoms (bloating, breast pain), menstruation dates
  • Confirms cyclical pattern: Symptoms in luteal phase, symptom-free interval in follicular phase
  • Differentiates from:
    • Depression/anxiety (symptoms present throughout cycle, no symptom-free interval)
    • Premenstrual exacerbation of underlying disorder (symptoms worse premenstrually but still present in follicular phase)

PMDD Diagnostic Criteria (DSM-5) - Requires ≥5 of the following, with ≥1 core symptom:

Core symptoms (≥1 required):

  • Marked mood swings
  • Marked irritability or anger
  • Marked depressed mood, hopelessness
  • Marked anxiety, tension

Additional symptoms:

  • Decreased interest in activities
  • Difficulty concentrating
  • Fatigue, low energy
  • Change in appetite, food cravings
  • Sleep disturbance
  • Feeling overwhelmed or out of control
  • Physical symptoms (breast tenderness, bloating)

This patient's diagnosis:

  • Prospective diary confirms: Severe mood symptoms (irritability, mood swings, anxiety, low mood) in luteal phase (days 18-28), symptom-free follicular phase (days 1-14)
  • Functional impairment: Sick days from work, relationship strain
  • Meets ≥5 DSM-5 criteria including core mood symptoms
  • Diagnosis: Premenstrual Dysphoric Disorder (PMDD)
Question 2: How is PMS/PMDD managed?

Management of PMS/PMDD - Stepwise Approach:

1. Lifestyle Modifications (First-line for ALL patients):

  • Exercise: Regular aerobic exercise (30 mins, 5x/week) - proven to reduce PMS symptoms
  • Diet:
    • Complex carbohydrates (whole grains) - stabilize blood sugar, reduce cravings
    • Reduce caffeine, alcohol, salt, refined sugar
    • Frequent small meals (reduce bloating)
  • Sleep hygiene: Regular sleep pattern, 7-9 hours/night
  • Stress management: Cognitive behavioural therapy (CBT), relaxation techniques, mindfulness, yoga

2. Dietary Supplements (Evidence-based):

  • Vitamin B6 (pyridoxine) 50-100mg daily: May reduce mood symptoms
  • Calcium 1000-1200mg daily: May reduce physical and mood symptoms
  • Magnesium 200-400mg daily: May reduce bloating, breast tenderness
  • Evening primrose oil: Weak evidence (not routinely recommended)

3. Pharmacological Management:

A) For Mild-Moderate PMS:

  • NSAIDs (mefenamic acid 500mg TDS): For physical symptoms (breast pain, headaches, dysmenorrhoea)
  • Combined Oral Contraceptive Pill (COCP):
    • Continuous regimen (back-to-back, no pill-free interval) - suppresses ovulation, eliminates luteal phase
    • Yasmin (drospirenone + ethinylestradiol) - anti-mineralocorticoid progestogen, reduces bloating/fluid retention
    • Takes 3-6 months to see full benefit

B) For Severe PMS / PMDD (First-line pharmacological):

  • SSRIs (Selective Serotonin Reuptake Inhibitors) - MOST EFFECTIVE for PMDD:
    • Fluoxetine 20mg, sertraline 50-150mg, citalopram 20mg, escitalopram 10-20mg
    • Dosing options:
      • Continuous daily: Take every day throughout cycle
      • Luteal phase only (days 14-28): Start after ovulation, stop when period starts (as effective as continuous, lower side effects)
    • Mechanism: Low serotonin implicated in PMDD - SSRIs rapidly (within days) improve mood symptoms
    • Efficacy: 60-70% symptom improvement
    • Onset: Effect within 1-2 days (unlike depression where takes 2-4 weeks)
    • Side effects: Nausea, sexual dysfunction, insomnia (usually mild)

C) For Refractory PMDD (Second-line if SSRIs + COCP fail):

  • GnRH analogues (goserelin, leuprorelin) + Add-back HRT:
    • Induce temporary medical menopause (suppress ovulation completely)
    • Very effective (70-80% improvement)
    • Requires add-back HRT (low-dose oestrogen + progestogen) to prevent menopausal symptoms and bone loss
    • Trial for 6 months - if effective, consider definitive treatment
  • Bilateral oophorectomy + HRT:
    • Definitive treatment - surgical menopause
    • Reserved for severe, refractory PMDD unresponsive to all other treatments
    • Requires lifelong HRT (until natural menopause age)
    • Only if GnRH analogue trial successful (confirms symptoms ovarian-hormone dependent)

4. Psychological Therapy:

  • Cognitive Behavioural Therapy (CBT): Evidence-based for PMDD - helps manage mood symptoms, coping strategies
  • Can be combined with pharmacological treatment

Treatment Algorithm Summary:

  1. All patients: Lifestyle (exercise, diet, stress management) + symptom diary
  2. Mild-moderate PMS: Lifestyle + supplements (B6, calcium) ± continuous COCP (Yasmin)
  3. Severe PMS/PMDD: Lifestyle + SSRI (luteal or continuous) ± CBT
  4. COCP + SSRI combination: If either alone insufficient
  5. Refractory PMDD: GnRH analogues + HRT → If successful, consider oophorectomy (last resort)

This patient's management plan (PMDD):

  1. Education and reassurance:
    • Explain PMDD is a real, treatable condition
    • Cyclical hormonal sensitivity (not "just in your head")
    • Excellent response to treatment expected
  2. Lifestyle modifications:
    • Regular exercise (30 mins, 5x/week)
    • Dietary changes (complex carbs, reduce caffeine/alcohol)
    • Stress management techniques
  3. First-line pharmacological: SSRI
    • Sertraline 50mg (luteal phase days 14-28) OR continuous daily
    • Start low, increase to 100-150mg if needed
    • Review in 3 months - expect 60-70% improvement
  4. Consider COCP (Yasmin) continuous:
    • Can add to SSRI if partial response
    • Suppresses ovulation, eliminates luteal phase
    • Provides contraception (family complete)
  5. CBT referral: Complement pharmacological treatment, coping strategies
  6. Follow-up: Continue symptom diary, review in 3 months, adjust treatment as needed
  7. Prognosis: Excellent - combination of SSRI + lifestyle ± COCP should provide significant relief

Key Learning Points