Background:

Major changes in female sex hormone concentrations influence the development of depressive symptoms in women. This hypothesis has been thoroughly investigated with regard to the menopause, the postpartal phase and also premenstrual dysphoric disorder. However, much less is known regarding the impact of female sex hormone fluctuations on depression during the regular menstrual cycle. There are indications that during the luteal phase, women might be more vulnerable to the development of depressive symptoms, while during the follicular phase and at ovulation, hormone concentrations might present a protective factor against depressive symptomatology. Subjective stress could mediate the relationship between depressive symptom development and the menstrual cycle phases. The complex interaction between sex hormones and psychological symptoms in the course of menstrual cycle phases is still understudied.

Method:

74 women (37 with and 37 without current depressive episode), will take part in a smartphone-based ambulatory assessment. Women will provide daily ratings of depressive symptoms and perceived stress for a period of one menstrual cycle (approx. 26-30 days). Three menstrual cycle phases will be assessed - the follicular phase, ovulation and the luteal phase. An ambulatory assessment will be used for these daily assessments. To assess the menstrual cycle phase participants will use ovulation tests on five days in the late follicular phase.

The following research questions will be investigated:

Research question 1: Do depressive symptoms (number and severity) change in the course of the menstrual cycle within the two groups? Research question 2: Which depressive symptoms are particularly sensitive to changes in the course of the menstrual cycle phases? Research question 3: Does the subjective stress change in the course of the menstrual cycle within the two groups? Research question 4: Are there differences between depressive and healthy women in terms of changes in depressive symptoms and subjective stress experience?

Implications:

The aim of the study is to investigate women-specific psychobiological factors influencing depression. Therefore, fluctuations in depressive symptoms and subjective stress experience will be investigated as a function of the respective menstrual cycle phases. The identification of cycle phases associated with increased or reduced vulnerability to depressive symptoms will support the development of women-specific prevention and treatment programs.

For participants with major depressive episode:

Inclusion criteria:

• female sex
• current diagnosis of a major depression episode
• minimum age of 18 years
• regular menstrual cycle.

Exclusion criteria:

• Pregnancy less than one year ago;
• women who are breastfeeding;
• bipolar disorder;
• acute suicidal tendencies;
• schizophrenic disorders (F20-29);
• substance use disorders
• psychotropic drugs in the last six months;
• chronic somatic diseases.

For participants without major depressive episode:

Inclusion criteria:

• female sex;
• minimum age of 18 years;
• regular menstrual cycle.

Exclusion criteria:

• current or lifetime mental disorder;
• pregnancy less than one year ago;
• women who are breastfeeding;
• psychotropic drugs in the last six months;
• chronic somatic diseases.

Sample will be recruited all over Germany.