The causes of PMDD (premenstrual dysphoric disorder) remain unknown, but the nature of PMDD symptoms is strongly suggestive of an interaction between hormonal fluctuations and brain chemistry. Some evidence also suggests a genetics play a role in PMDD.
Hormones, Serotonin, and Symptoms of PMDD
It’s reasonable to assume that premenstrual dysphoric disorder occurs due to imbalances in ovarian hormones and their fluctuation during the menstrual cycle. After all, PMDD symptoms are closely tied to menstruation. The truth is more complex.
Studies of PMDD symptoms reveal no difference between the ovarian hormone levels of women with and without premenstrual dysphoric disorder, yet hormones must play some role in PMDD symptoms: menopause or removal of the ovaries end symptoms of PMDD.
The most common explanation is that chemical messengers in the brain called neurotransmitters react abnormally to changes in hormone levels. Low levels of the neurotransmitter serotonin are thought to cause depression, and may be one of the causes of PMDD. This may explain why SSRRIs, antidepressants that regulate serotonin, are an effective PMDD treatment. The link to brain chemistry is why premenstrual dysphoric disorder is considered a mental health disorder rather than a hormonal disorder.
Genetic PMDD Causes
There are some indications that genetics cause PMDD, or at least increase the risk of PMDD symptoms. Identical twins have a 93 percent chance of both having PMDD symptoms, as opposed to 44 percent of fraternal twins. Daughters of women with PMDD are at a higher risk of developing PMDD symptoms themselves.
While this evidence suggests a genetic cause of PMDD, no genetic cause of premenstrual dysphoric disorder has yet to be identified.
Discredited Causes of PMDD
Over the years a number of possible PMDD causes have been ruled out. While stress certainly worsens symptoms of PMDD it is no longer considered to cause the disorder. Suggestions that premenstrual dysphoric disorder were somehow caused by personality disorders or certain personality types have also been discredited, as have theories that PMDD symptoms somehow reflected a woman’s attitude towards menstruation.
While the causes of PMDD remain unproven, PMDD treatment is very effective, especially with the realization that SSRI antidepressants reduced premenstrual dysphoric disorder. PMDD diagnosis can be difficult, but diagnostic tools should improve when the root cause of premenstrual dysphoric disorder is finally identified.