What are the differences between Premenstrual Syndrome (PMS) and Premenstrual Dysphoric Disorder (PMDD) and how are they treated?

Premenstrual Syndrome (PMS) vs. Premenstrual Dysphoric Disorder (PMDD): Differences and Treatment

PMS and PMDD are distinct conditions with different severity levels and treatment approaches, with PMDD being a more severe form that significantly impacts daily functioning and requires more intensive intervention.

Key Differences Between PMS and PMDD

Definition and Prevalence

• PMS affects 20-40% of menstruating women and is characterized by physical and psychological symptoms occurring during the luteal phase of the menstrual cycle 1
• PMDD is a more severe form affecting 3-8% of menstruating women, officially recognized as a distinct diagnostic entity by both the American Psychiatric Association in the DSM-5 and the World Health Organization in the ICD-11 2, 3

Symptom Severity and Impact

• PMS involves milder symptoms including fatigue, irritability, mood swings, abdominal bloating, breast tenderness, and food cravings 1
• PMDD involves more severe symptoms that substantially interfere with daily activities, work, school, social activities, or relationships 2, 4

Diagnostic Criteria

• PMS is primarily diagnosed clinically with characteristic symptoms occurring in the luteal phase and resolving during or shortly after menstruation 4
• PMDD requires meeting specific diagnostic criteria outlined in the DSM-5, including marked affective symptoms (irritability, mood swings, depression) that significantly impair functioning 2, 3

Diagnosis and Assessment

Symptom Tracking

• Both conditions require symptom tracking for at least two menstrual cycles using tools like the Daily Record of Severity of Problems to identify cyclic patterns 4
• For PMDD diagnosis, symptoms must be present in the majority of menstrual cycles, occur during the luteal phase, improve with onset of menses, and be absent in the week after menses 3

Treatment Approaches

First-Line Treatments

For PMDD:

• Selective Serotonin Reuptake Inhibitors (SSRIs) are the established first-line treatment for PMDD with rapid onset of improvement 5, 6
• Specific SSRIs with demonstrated efficacy include sertraline (50-150 mg/day), fluoxetine (10-20 mg/day), escitalopram (10-20 mg/day), and paroxetine (12.5-25 mg/day) 6
• SSRIs can be administered continuously, intermittently (luteal phase only), or symptom-onset dosing, with all approaches showing efficacy 3

For PMS:

• Milder interventions may be sufficient, including lifestyle modifications, supplements, and over-the-counter pain relievers 1
• SSRIs may be used for more bothersome PMS symptoms but at lower doses than for PMDD 4

Hormonal Treatments

• Drospirenone-containing oral contraceptives (3 mg drospirenone with 20 μg ethinyl estradiol) have shown efficacy for PMDD in clinical trials 7
• FDA-approved drospirenone/ethinyl estradiol formulations can treat PMDD in women who choose to use oral contraceptives for birth control 7

Non-Pharmacological Approaches

• Cognitive Behavioral Therapy (CBT) shows positive results in reducing functional impairment, depressed mood, and anxiety in PMDD patients 2, 6
• Exercise, acupuncture or acupressure may help ameliorate both PMS and PMDD symptoms 4

Supplements and Herbal Treatments

• Calcium supplementation has demonstrated consistent therapeutic benefit for PMS symptoms 5
• Vitex agnus castus (chasteberry) may be beneficial for some women with PMS or milder PMDD symptoms 4

Treatment Algorithm

1. Confirm diagnosis through symptom tracking for at least two menstrual cycles 4
2. Assess severity:
   • For PMS: Begin with lifestyle modifications, calcium supplements, and OTC pain relievers 1
   • For PMDD: Proceed to pharmacological intervention 5, 6
3. For PMDD, initiate SSRI therapy:
   • Start with sertraline 50 mg/day, fluoxetine 10 mg/day, or escitalopram 10 mg/day 6
   • Consider continuous or luteal phase dosing based on symptom pattern 3
4. If patient desires contraception:
   • Consider drospirenone-containing oral contraceptives (3 mg drospirenone/20 μg ethinyl estradiol) 7
5. For inadequate response:
   • Increase SSRI dose within recommended ranges 6
   • Add CBT or other non-pharmacological approaches 2, 6
6. For treatment-resistant cases:
   • Consider combination therapy (SSRI plus hormonal treatment) 5
   • Reassess for other underlying conditions if symptoms persist throughout the month 4

Common Pitfalls and Caveats

• Misdiagnosis is common - ensure symptoms follow a cyclical pattern by tracking for at least two months 4
• Don't confuse PMDD with exacerbation of underlying psychiatric disorders during the premenstrual phase 3
• SSRIs for PMDD work more rapidly than for depression, often within days rather than weeks 3
• Drospirenone-containing contraceptives should not be used in women with conditions that predispose to hyperkalemia 7
• Regular reassessment is necessary as symptoms can change over time and with life transitions 4