Rapid response to fluoxetine in women with premenstrual dysphoric disorder

Selective serotonin reuptake inhibitors (SRIs) relieve irritability within days in women with premenstrual dysphoric disorder (PMDD); however, the effects on other affective symptoms in PMDD remain to be demonstrated.

We performed hourly ratings in women with PMDD to test the specificity of the therapeutic effects of SRIs and to determine whether the kinetics of these effects differ from those of the symptom offset accompanying menses. Twelve women with PMDD received fluoxetine (20 mg daily) during the luteal phase of the menstrual cycle. Twelve other women with PMDD received no treatment. Outcome measures included a visual analogue scale completed hourly before and after either the start of SRIs or at menses-onset in the untreated women and the premenstrual tension syndrome (PMTS) scale completed daily. Data were analyzed by ANOVA-R.

Hourly VAS scores significantly improved after SRI in irritability as well as sadness, anxiety, and mood swings. Compared with the symptomatic pretreatment baseline, PMTS scores significantly improved on the second day after the start of SRI (p < .01). An identical time course of symptom improvement occurred after both SRI and menses-onset.

These data document that the rapid response to SRI was not limited to irritability. The similar kinetics in the remission of PMDD after SRIs and after menses-onset suggest both a phenotype reflecting the relative capacity to rapidly change affective state, and a possible therapeutic mechanism by which SRIs recruit this endogenous capacity to change state, normally expressed around menses-onset in women with PMDD.