Premenstrual Dysphoric Disorder (PMDD) & Premenstrual Syndrome (PMS)

Introduction

For MCCQE1 preparation, understanding the spectrum of premenstrual disorders is crucial. These conditions range from mild physiological symptoms to severe impairment known as Premenstrual Dysphoric Disorder (PMDD).

As a Canadian medical graduate, you must be able to distinguish these conditions from primary psychiatric disorders (like Major Depressive Disorder) and underlying medical conditions. This topic bridges Psychiatry and Gynecology, reflecting the integrative nature of the Medical Council of Canada (MCC) objectives.

Definitions

• Premenstrual Syndrome (PMS): A cluster of physical and distinct mood symptoms that occur in the luteal phase of the menstrual cycle and resolve with menstruation. It causes some level of distress or impairment.
• Premenstrual Dysphoric Disorder (PMDD): A severe form of PMS characterized by significant affective symptoms (irritability, anger, dysphoria) that cause marked functional impairment. It is classified in the DSM-5-TR under Depressive Disorders.

Epidemiology and Pathophysiology

Canadian Context

• PMS: Affects up to 75% of reproductive-age women in Canada to some degree; clinically significant PMS affects 20-30%.
• PMDD: Affects approximately 3-8% of menstruating women.

Etiology

The exact mechanism is unknown, but the prevailing theory suggests an abnormal neurotransmitter response (specifically serotonin and GABA) to normal hormonal fluctuations (estrogen and progesterone) during the luteal phase.

Clinical Presentation

Symptoms must follow a specific temporal pattern to meet diagnostic criteria.

Timing

• Onset: Luteal phase (typically 1-2 weeks before menses).
• Resolution: shortly after the onset of menstruation (follicular phase).
• Symptom-Free Interval: There must be a symptom-free period in the follicular phase (after menses stops and before ovulation).

Symptomatology

Diagnosis

Diagnosis is clinical but requires prospective documentation. Retrospective reporting is often unreliable due to recall bias.

Diagnostic Criteria (DSM-5-TR for PMDD)

To diagnose PMDD, symptoms must be present in the final week before onset of menses, start to improve within a few days after the onset of menses, and become minimal or absent in the week post-menses.

At least 5 symptoms must be present (with at least one from “Core Affective Symptoms”):

1. Core Affective Symptoms (Must have at least one):
   • Marked affective lability
   • Marked irritability/anger
   • Marked depressed mood
   • Marked anxiety/tension
2. Additional Symptoms:
   • Decreased interest in activities
   • Difficulty concentrating
   • Lethargy
   • Appetite change
   • Sleep change
   • Overwhelmed feeling
   • Physical symptoms (bloating, breast tenderness)

The Diagnostic Gold Standard

The MCCQE1 often tests the initial management of a patient presenting with these symptoms. The correct answer is often prospective charting before starting medication.

Differential Diagnosis

It is vital to rule out PME (Premenstrual Exacerbation) of an underlying disorder.

Management

Management should follow a stepwise approach, aligning with SOGC (Society of Obstetricians and Gynaecologists of Canada) guidelines.

Canadian Guidelines (SOGC)

The Society of Obstetricians and Gynaecologists of Canada (SOGC) emphasizes:

1. Prospective charting is mandatory for a definitive diagnosis.
2. SSRIs are the first-line pharmacologic treatment for severe PMDD.
3. Calcium (1200mg) and Vitamin D are recommended as supportive therapy.
4. Drospirenone-containing OCPs are the preferred hormonal option.

Key Points to Remember for MCCQE1

• Symptom-Free Interval: If the patient has symptoms during the follicular phase (after menses ends), it is likely not PMDD. Consider MDD or PME.
• Documentation: Do not diagnose PMDD on the first visit based on recall. Order a symptom diary (DRSP) for 2 months.
• Suicide Risk: PMDD is associated with increased suicidality in the luteal phase; assess safety.
• Treatment Response: SSRIs work rapidly for PMDD (unlike in MDD). Luteal phase dosing is unique to this condition.
• Abbreviations:

  PMDD: Premenstrual Dysphoric Disorder
  PMS: Premenstrual Syndrome
  DRSP: Daily Record of Severity of Problems
  SSRIs: Selective Serotonin Reuptake Inhibitors
  GnRH: Gonadotropin-Releasing Hormone

Sample Question

Case Scenario

A 29-year-old female presents to her family physician with a complaint of “severe mood swings” that have been worsening over the past year. She reports feeling extremely irritable, bloated, and hopeless starting about 10 days before her period. These symptoms result in her missing 1-2 days of work monthly. She states that “within a day or two” of her period starting, she feels “completely back to normal” and functions well at work and home. She has no prior history of psychiatric hospitalization. Physical examination is unremarkable.

Question

Which one of the following is the most appropriate next step in management?

Options

• A. Initiate treatment with Fluoxetine 20 mg daily
• B. Initiate treatment with a combined oral contraceptive pill
• C. Request the patient complete a daily symptom diary for two menstrual cycles
• D. Order TSH, CBC, and Ferritin levels
• E. Refer to a psychiatrist for evaluation of Bipolar II Disorder

Explanation

The correct answer is:

• C. Request the patient complete a daily symptom diary for two menstrual cycles

Detailed Explanation: The clinical presentation is highly suggestive of Premenstrual Dysphoric Disorder (PMDD) given the timing (luteal phase onset, resolution with menses) and the severity (functional impairment). However, Canadian guidelines and standard of care dictate that a diagnosis of PMDD should be confirmed with prospective charting (using a tool like the DRSP) for at least two cycles to distinguish it from Premenstrual Exacerbation (PME) of another disorder or retrospective recall bias.

• Option A: While SSRIs are first-line treatment, diagnosis must be confirmed first.
• Option B: OCPs are second-line to SSRIs for PMDD and, again, diagnosis requires confirmation first.
• Option D: While ruling out medical causes is important, the history is classic for PMDD. However, the most appropriate specific step for the suspected PMDD is the diary. Basic labs might be done concurrently, but the diary is the diagnostic gold standard for the specific complaint.
• Option E: Bipolar disorder is a differential, but the strict cyclic nature with a clear symptom-free interval points more strongly to PMDD. Referral is not the initial step.

References

1. American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev.).
2. Reid, R. L., et al. (2023). “Premenstrual Dysphoric Disorder: Clinical Practice Guideline.” Journal of Obstetrics and Gynaecology Canada (JOGC). (Based on SOGC Guidelines).
3. Medical Council of Canada. (2024). MCCQE Part I Clinical Decision-Making and Objectives.
4. UpToDate. (2024). Clinical manifestations and diagnosis of premenstrual dysphoric disorder.
5. Toronto Notes. (2024). Psychiatry & Gynecology Sections.