🎗️What Does Serotonin Have To Do With Anger And Impulse Control Before Menstruation?

What if premenstrual irritability wasn't just about mood, but also about how the brain controls our impulses? A study involving women with severe premenstrual irritability found that escitalopram, in addition to reducing anger and irritability, also altered performance on a task assessing response control. These results help reveal a fascinating connection between the menstrual cycle, serotonin, emotions, and behavior.

Many women notice significant mood changes in the days leading up to menstruation. For some, however, these changes are far more intense: irritability, anger, mood swings, difficulty concentrating, and a feeling of losing control can interfere with work, relationships, and daily life.

When various symptoms repeatedly appear during this phase of the cycle and vanish after menstruation begins, the condition may be premenstrual dysphoric disorder. While it is already known that medications increasing serotonin availability in the brain can alleviate symptoms, particularly irritability and anger, it was previously unclear whether such treatment could also modify behaviors related to impulsivity when measured directly in a laboratory setting.

To investigate this issue, researchers monitored 27 women over the course of three menstrual cycles. First, the women regularly recorded how they were feeling, using scales to rate the intensity of various mood-related symptoms. This initial phase was crucial, as it allowed researchers to determine whether the symptoms actually tracked with the menstrual cycle rather than occurring randomly.

Particular emphasis was placed on irritability and anger: to proceed to the main part of the study, participants had to exhibit a change clearly linked to the premenstrual phase.

Over the next two cycles, participants received either escitalopram or a placebo at different times, without knowing which one they were taking. Escitalopram is a medication that increases the amount of serotonin available for communication between nerve cells. The study employed a crossover design: each participant experienced both conditions at different times, enabling a comparison of the same individual's response while taking the medication versus the placebo.

Treatment was administered only during the phase of the cycle when symptoms typically appeared, rather than continuously throughout the month. This is particularly interesting because previous studies had already shown that premenstrual symptoms can respond rapidly to this type of medication.

However, the researchers wanted to go beyond the participants' self-reports. During the premenstrual phase of the cycles in which they were receiving either escitalopram or a placebo, the participants performed a computerized test of attention and response control. The task presented stimuli on a screen and required participants to respond quickly, but only when specific signals appeared.

The goal was to observe what happened when a person needed to control the impulse to respond prematurely and maintain a steady response speed throughout the task. In other words, the test allowed for a more objective investigation of aspects related to attention and behavioral control. Participants also completed an impulsivity questionnaire at two points in the cycle during the placebo condition: before menstruation and during the phase of the cycle following menstruation.

This questionnaire assessed various characteristics of impulsivity, as being impulsive does not merely mean acting quickly; it can also involve difficulty resisting intense emotions or a greater tendency to seek out new and stimulating experiences.

The results showed that escitalopram did indeed reduce irritability and anger during the premenstrual phase. However, an interesting difference also emerged in the laboratory test: while taking the medication, the women exhibited fewer anticipatory responses, meaning they made fewer errors by responding before the appropriate moment.

Furthermore, their response speed became more consistent. The questionnaires also revealed that, during the premenstrual phase of the cycle in which they received a placebo, the participants showed a greater tendency toward "urgency", a heightened propensity to act under the influence of intense emotions, compared to the post-menstrual phase of the cycle.

Interestingly, the comparison also showed a lower tendency toward sensation-seeking. This demonstrates that impulsivity related to the menstrual cycle is not necessarily a single, simple phenomenon but can involve various aspects of behavior.

The study, therefore, suggests that premenstrual irritability may be accompanied not only by a subjective change in mood but also by measurable alterations in how the brain controls impulsive responses. Since serotonin plays a role in the circuits involved in regulating emotions and behavior, the effects observed with escitalopram raise the possibility that these mechanisms are linked to the behavioral changes some women experience before menstruation.

However, it is important not to interpret the results as proof that all premenstrual impulsivity is caused by a serotonin deficiency, nor that the medication is indicated for every woman experiencing irritability.

The study was small and specifically evaluated women with severe premenstrual irritability. The main finding was that treating emotional symptoms also appeared to modify an objective measure of response control, reinforcing the idea that premenstrual dysphoric disorder involves a complex interaction between the menstrual cycle, the brain, emotions, and behavior.

READ MORE:

The effects of intermittent escitalopram treatment on impulsivity and inattention in women with premenstrual irritability and anger

Gröndal M, Englund C, Näslund J, Ask K, Eriksson E, and Winblad S. Psychological Medicine. 2025;55:e301. 

doi:10.1017/S0033291725102055

Abstract: 

Women diagnosed with premenstrual dysphoric disorder (PMDD) report significant symptom relief when treated with selective serotonin reuptake inhibitors, but few studies have addressed the possibility of capturing this effect in behavioral, laboratory-based tests. This study examined the effects of intermittent treatment with escitalopram (vs. placebo) on a behavioral measure of impulsivity and inattentiveness in women reporting high levels of premenstrual irritability and anger. Participants (N = 27) rated cardinal PMDD mood symptoms over three menstrual cycles using Visual Analogue Scales. In Cycles 2 and 3, participants displaying cyclicity with respect to the irritability/anger item received escitalopram (20 mg) or placebo in a randomized, single-blind, crossover design. The participants completed the Conners Continuous Performance Test (CPT 3) in the luteal phase of the intervention cycles. Additionally, they filled out the UPPS Impulsive Behavior Scale, once in the luteal phase and once in the follicular phase of the placebo cycle. In line with previous reports, escitalopram caused a significant reduction in self-rated irritability and anger in the luteal phase. When on escitalopram, the participants demonstrated a lower frequency of anticipatory responses and greater consistency in response speed in the CPT 3. With respect to self-reported impulsivity, participants reported higher levels of urgency and lower levels of sensation seeking in the luteal placebo phase versus the follicular phase. The finding that escitalopram impacted the outcome of the CPT 3 test in women with premenstrual irritability highlights the possible role of impulsivity in this condition.