Uppsala University: symptom diaries of 90 women reveal three subtypes of premenstrual dysphoric disorder

Researchers led by Erika Comasco, professor of Molecular Psychiatry at Uppsala University, report that premenstrual dysphoric disorder (PMDD) has three subtypes with different symptom patterns. The study was published in Nature Communications and covered by miragenews.com miragenews.commiragenews.commiragenews.comOpen source ↗. It involved 90 women with PMDD and 40 healthy controls.

PMDD is a more severe form of premenstrual syndrome that affects women in their childbearing years. Unlike other mood disorders, it is tied to the menstrual cycle: symptoms can start shortly after ovulation and continue until menstruation begins.

Three subtypes from two months of diaries

For two months, participants kept a diary and rated the severity of anxiety, depression, irritability and mood swings. Using statistical methods, the researchers analysed when each symptom appeared and subsided, and how changes in one symptom affected the others.

The three subtypes were as follows [1]:

• Severe PMDD with early onset: symptoms begin roughly two weeks before menstruation and are strongest about five days before it.
• Severe PMDD with late onset: symptoms start increasing about ten days before menstruation and peak around its beginning.
• Moderate PMDD with late onset: symptoms also start rising about ten days before menstruation, peak about four days before it, and are less severe than in the other two subtypes.

According to Comasco, two people with the same diagnosis can differ in symptom onset, severity and offset, and different symptoms in the same person can follow different patterns miragenews.commiragenews.commiragenews.comOpen source ↗.

Interaction of symptoms and open questions

The researchers also observed a temporal interaction between the four most common symptoms. For example, an increase in anxiety was followed by increased irritability, depressive symptoms and mood swings. The authors note that more research is needed before this can be used to predict the course of PMDD in an individual.

The study does not explain why the subtypes differ. The group plans to examine the biological mechanisms and their link to brain function, combining the symptom timeline with brain studies and the effects of pharmacological treatment. They will also test whether the subtypes are associated with differences in brain function and treatment response.

Some of the participants also took part in a brain imaging study published in the British Journal of Psychiatry. It reported that treatment with the SSRI escitalopram reduced irritability, anger and aggression, and made the anterior insula less reactive to social provocation miragenews.commiragenews.commiragenews.comOpen source ↗. The authors say they hope the findings will eventually allow more individualised monitoring and treatment.