PMS vs. PMDD - Whats' the Difference?

Medical Author: Carolyn Janet Crandall, M.D., FACP
Medical Editors: Melissa Conrad Stöppler, MD and William C. Shiel Jr., MD, FACP, FACR

Ms. B.T. is 38 years old. Her co-workers always seem to know when she has her period. During this time, she becomes extremely irritable. She feels guilty because she gets very angry at her children for no logical reason or for apparently trivial reasons. In fact, one of her coworkers, with whom she is quite friendly, suggested she come in before her supervisor noticed problems on the job. She heard that there is a severe version of PMS that requires special treatment. Ms. B.T. wants to know if this is her problem.

Premenstrual syndrome (PMS) has been the term used for mood, and sometimes physical, symptoms that occur cyclically (predictably in relation to menses) in the second half of the menstrual cycle and interfere with a woman's quality of life. Some women experience even more severe symptoms. These women may have a conditions known as premenstrual dysphoric disorder (PMDD).

In order to determine what condition is affecting Ms. B.T., the doctor first requests that she keep a symptom diary, which is required for the diagnosis of PMDD. In the diary, she records in detail her mood and physical symptoms, and eating and sleeping patterns over two menstrual cycles.

Ms. B.T. returns to the doctor with her diary. The doctor is interested in the10 symptoms listed below, regarding her premenstrual symptoms. For the diagnosis of PMDD, she must have at least five symptoms on the list (including at least one of the first four) cyclically in the time prior to her menstrual period.

1. markedly depressed mood, feelings of hopelessness, or self-deprecating thoughts (thoughts of being "harsh" on herself, feeling like she is worthless);
   
   
2. significant anxiety or tension;
   
   
3. marked swings in emotions (for example, becoming tearful easily and frequently);
   
   
4. persistent and pronounced anger or irritability, or increased conflicts with other people;
   
   
5. decreased interest in usual activity;
   
   
6. difficulty concentrating;
   
   
7. sluggishness, easy fatigue, lack of energy;
   
   
8. substantial change in appetite, food cravings, overeating;
   
   
9. excessive sleeping or insomnia; and
   
   
10. physical symptoms such as breast pain, bloating, or headaches.

In her diary, Ms. B.T. confirms that she becomes extremely anxious and tense just before her period begins. At that time, she has trouble concentrating at work. She develops insomnia, breast pain, and bloating. She keeps sweets in her drawer at work because she craves them monthly. Ms. B.T. has the symptoms of PMDD. However, the doctor needs to confirm with her that these symptoms are not due to the worsening of a physical or emotional disorder that was already present, such as depression.

In some patients, it may be difficult to distinguish PMDD from depression. Furthermore, a woman with PMDD is at an increased risk of having depression at some point in her life. Because alcohol and drug use can cause a variety of mood symptoms, including anxiety, the doctor asks Ms. B.T. about alcohol and drug use. She states that she avoids alcohol because of concern that alcohol will make her more moody and angry. She denies any drug use.

Lastly, Ms. B.T. has her blood drawn for thyroid function tests. This is because women with an overactive thyroid can have significant anxiety and insomnia. Her thyroid test comes back normal.

Well, it looks like Ms. B.T. does have PMDD. When women are diagnosed with PMDD, they may be relieved to know that they are not alone, and that PMDD is not a sign of any serious medical illness. PMDD is often treated simply because it interferes with a woman's daily life, not because it will place her in any physical danger. Fluoxetine (Sarafem) and (paroxetine) Paxil CR are among the drugs that have been effective for treating PMDD, but there are other medications that are sometimes used. These drugs are not approved for the treatment of PMS, but only for severe PMDD symptoms.

There are behavioral therapy techniques that can help women with PMDD as well, such as anger and stress management. Women who are concerned that they have PMDD should be evaluated by a health care practitioner to determine what treatments are available for them. For those who have PMS and not PMDD, a doctor can also discuss general strategies that might be helpful.

Reference: Harrison''s Principles on Internal Medicine, 14th edition, 2006