Microdosing LSD in Women With Premenstrual Disorders

Inclusion crtieria:

* Between 18-45 years.
* Are menstruating and have cycles with a duration between 21 - 35 days.
* Meet DSM-V criteria for PMDD or criteria for severe PMS with daily ratings over 2 cycles to confirm luteal symptoms.

  1. For PMDD, participants must have a minimal average luteal phase score of mild (≥3 on a 6-point scale) for at least 5 Symptoms on the DRSP including 1 mood symptom during the 5 most symptomatic of the final 7 luteal phase days and the first 2 days of menses onset, and the average follicular phase score must not be \>2 on these same items.
  2. For severe PMS, participants must have a minimal average luteal phase score of mild (≥3 on a 6-point scale) for at least 4 Symptoms on the DRSP including 1 mood symptom, during the 5 most symptomatic of the final 7 luteal phase days and the first 2 days of menses onset, and the average follicular phase core must not be \>2 on these same items.
* Have reported PMDD/PMS symptoms for the majority of menstrual cycles (\>9 of 12) during the year prior to screening.
* Sufficient understanding of the German language
* Sufficient understanding of the study procedures and risks associated with the study.
* Participants must be willing to adhere to the study procedures and sign the consent form.
* Willing not to drive or operate heavy machinery during the acute treatment phases of the study.
* Willing to refrain from more than 7 standard alcoholic drinks a week, more than 10 cigarettes a day, and any illicit substances.
* Willing to use effective contraceptive measures throughout study participation.

Exclusion Criteria:

* Known hypersensitivity to LSD
* Current treatment for PMS/PMDD
* Use of an oral hormonal contraceptive \< 6 months.
* Past or present bipolar or psychotic disorder, including depressive disorder with psychotic features.
* First degree relative with a psychotic disorder.
* Significant prodromal psychotic symptoms (Prodromal Questionnaire-16 symptoms ≥ 6).
* Borderline personality disorder.
* Current post-traumatic stress disorder.
* Pregnant or breastfeeding
* Planned pregnancy.
* Current or recent history of significant suicide ideation or suicide behavior within the past 6 months.
* Current substance use disorder (\< 12 months) other than tobacco smoking.
* Other illness that excludes repeated LSD administration or requires interfering medication.
* Participation in another clinical trial (currently or within the last 30 days)