Premenstrual Syndrome (PMS) vs. Premenstrual Dysphoric Disorder (PMDD)

Frederick R. Jelovsek MD

Premenstrual syndrome (PMS) refers to the variation of physical and mood symptoms that appear during the last one or two weeks of the menstrual cycle and disappear by the end of a full flow of menses. This is a diagnosis used by Ob-Gyns and primary care physicians. Psychiatrists and other mental health workers tend to use the diagnosis term of premenstrual dysphoric disorder (PMDD) to describe a specific set of mood symptoms that are also present the week before menses and remit a few days after the start of menses and also interfere with social or role functioning. Is there any difference between the two or do they represent the same entity? Most doctors believe these two terms refer to the same clinical entity.

A recent educational series from the Association of Professors of Obstetrics and Gynecology, Ling FW, Mortola JF, Pariser SF st al.: Premenstrual syndrome and premenstrual dysphoric disorder: Scope, diagnosis, and treatment. 1998 Pragmaton, Chicago IL., looked at the components that go in to each of these diagnoses.

How common is PMS?

Up to 80% of women have cyclic symptoms associated with their menses but only about 3-5% have symptoms so severe that it interferes with work, school, usual activities or relationships. The average onset is 26 years of age with symptoms often becoming worse over time. Other mental health problems and diagnoses are often associated with PMS and PMDD, especially major and minor depression.

What are some of the actual symptoms of PMS and PMDD?

PMS looks more at physical symptoms such as bloating, weight gain, breast tenderness, swelling of hands and feet, aches and pains, poor concentration, sleep disturbance, appetite change, and psychologic discomfort. Premenstrual dysphoric disorder has as part of its definition, symptoms such as depressed mood or dysphoria, anxiety or tension, emotional lability, irritability, decreased interest in usual activities, concentration difficulties, marked lack of energy, marked change in appetite, overeating or food cravings, sleepiness or insomnia, and feeling overwhelmed.

What other diagnoses can be confused with PMS and PMDD?

The differential diagnosis includes:
Psychiatric disorders

• major depression
• minor depression (dysthymia)
• generalized anxiety
• panic disorder
• bipolar illness (mood irritability)
• other

Medical disorders

• anemia
• autoimmune disorders
• hypothyroidism
• diabetes
• seizure disorders
• endometriosis
• chronic fatigue syndrome
• collagen vascular disease

Many times it is extremely difficult to rule out a premenstrual exacerbation of another mood or physical disease versus a primary diagnosis of PMS or PMDD, or even the possible combination of both a medical or psychologic disorder and PMS.

What causes PMS?

There is moderate evidence to support the theory that premenstrual symptoms are caused primarily by changes in brain chemicals that transmit between nerves and cells (neurotransmitters) brought about by cyclical fluctuations in ovarian hormones. PMS does not occur before menarche, during pregnancy and after menopause, either natural or surgical.

Is PMS hereditary?

Current research indicates that there is a possible genetic factor in the development of PMS and may explain as high as 35% of symptoms. Several studies of twins indicate a higher incidence of PMS symptoms in identical female twins versus non-identical female twins. Family environment may also play a role in that a high prevalence of a history of sexual abuse has been found in women seeking treatment for PMS.

What can I do to see if I have PMS?

You need to see your doctor to make sure none of the other problems are confusing the symptoms. The doctor will probably check your thyroid studies (TSH), blood sugar for diabetes, blood count for anemia and evaluate your history and physical findings to rule out automimmune disease, vascular disease, seizures and endometriosis among others. The doctor may want you to take some psychometric written tests to see if depression, anxiety or even panic disorder are playing a role in your symptoms.

The hallmark of PMS diagnosis is prospective symptom charting. Without it, the diagnosis of PMS cannot be accurately made. The reason for this is that retrospective recall has almost always been found to be markedly different from prospective charting. While you may think there is a one-to-one variation of symptoms with your menstrual cycle, prospective charting often shows that symptoms are present all of the time and represent basically a mood disorder more than just PMS. That mood disorder is where treatment needs to be directed. The doctor will give you a chart to track the severity of some of your symptoms over one or two months. There needs to be at least a week that is symptom free in the first part of your menstrual cycle in order to diagnose PMS.

What are some of the possible treatments for PMS?

The best treatments are often the simplest. Dietary change can help dramatically. Discontinuance of all caffeine containing products, drinks and over-the-counter-medications. A low carbohydrate diet, especially avoiding any simple sugars and only sparingly having complex carbohydrates is beneficial. Calcium supplements (1200 mg/day) also have been shown to help. Vitamin B6 (pyridoxine) has contradictory evidence of its efficacy and progesterone treatment used in the past has been shown to be no better than placebo.

Common prescription medicines used are included in the table below:

Class of drug	Medicine	Dose
Antidepressants	fluoxetine (Prozac®)	20 mg/day
	sertraline (Zoloft®)	50-150 mg/day
	paroxetine (Paxil®)	10-30 mg/day
	clomipramine (Anafranil®)	25-75 mg/day (14 days before menses)
Antianxiety	alprazolam (Xanax®)	1-2 ug/day (6-14 days before menses)
	buspirone (Buspar®)	25-60 mg/day (12 days before menses)
Ovulation suppression	GnRH agonist Lupron®	3.75 - 7.5 mg/monthly I.M.
	GnRH agonist Buserelin	400-900 ug/day intranasal