This intervention study aims to evaluate the effectivity of web-based cognitive therapy in reducing depression and anxiety in pregnant and postpartum women. Moreover, it aims to assess treatment feasibility and usability of the treatment in the same population.

After an initial screening to determine the eligibility to participate, all participants fulfilling the inclusion criteria will receive their personal access login in order to start the intervention.

Introduction: Evidence has shown that 10-20% of women suffer from depression during gestation and after birth (Barnes, 2014; Zaers, Waschke & Ehlert, 2008), while 7-21% present clinically relevant anxiety levels prenatally and following delivery (Grant, McMahon & Austin, 2008).

Previous research has shown that if a woman has high levels of depression or anxiety during pregnancy her child is at about double the risk for attention deficit hyperactivity disorder, conduct disorders, difficult temperament and behavioural problems later in development (O'Connor et al., 2002). High levels of prenatal anxiety and depression are frequently comorbid (Amiel Castro et al., 2016) and together with stress have been shown to increase risk for preterm delivery, low birth weight, impaired memory and cognitive function among others (Talge, Neal & Glover, 2007). The important biopsychological changes brought by the perinatal period (Ehlert et al., 1990) require constant attention from health workers since they carry relevant risk factors for the mother's health and for the infant's neurodevelopment (Schetter & Tanner, 2012).

Current depression interventions are not deliverable to a large number of individuals (Andersson & Titov, 2014). As seen worldwide, the difficulty to receive proper treatment for depression and anxiety is also evident in Switzerland. About half of people suffering from depression and/or anxiety are not diagnosed and consequently do not receive any sort of psychological or pharmaceutical treatment (Baer et al., 2013).

The internet offers an opportunity to deliver tailored interventions such as those based on cognitive behavioural therapy (CBT) to a large audience, cost-effectively, while preserving intervention fidelity and anonymity. The potential effectiveness of the internet is indicated by research demonstrating the successful delivery of CBT by computer and the use of the internet in the delivery of CBT treatment (Andrews et al., 2010). Recent reviews of the evidence have recommended further research that includes long-term follow-up and evaluation of novel treatment modalities such as the ones provided by internet (Dennis et al., 2012). Moreover, online interventions have been widely explored for different mental health problems (Sourander et al., 2016) suggesting its potential to increase access to and uptake of services for women with a perinatal disorder.

The "Willkommen Mutterglück" program is an 8-session, interactive web-based cognitive behavioural intervention for prenatal and postpartum depression and anxiety.

Given the prevalence rates of depression and anxiety during the perinatal period and the rates of untreated patients, it is important to propose treatment alternatives. Several reviews on the area emphasize that topics such as type and amount of CBT material incorporated to the program, length and frequency of sessions, amount of homework given and frequency of minimal therapist intervention are related to effectivity of online interventions and warrant further research. Also, it is unclear whether therapist contact focusing on motivation to complete the program is more effective than non-therapist contact in the treatment of the disorders. Therefore, routine use of this online intervention for depressed and anxious mothers is only possible if this program/the effects are is scientifically evaluated with biomarkers.

The primary goal of this project is to investigate the effectiveness of an online cognitive behavioural intervention specifically tailored to pregnant and postpartum women in reducing depression and anxiety symptoms. The secondary goal is to assess the feasibility and usability of this intervention on the treatment of depression and anxiety.

Method: The investigators aim to recruit N=300 patients from the first gestational trimester to one year after birth. The eight intervention sessions are administered online via audio and video images. The participants are asked to actively participate during their weekly session through exercises and quizzes. Each weekly session has a duration of 40-50 minutes.

A SCID interview for screening will be conducted by a trained clinical psychologist and an experienced psychiatrist from a trusted Outpatient Clinic will verify the diagnosis. Screened and consented participants will then fill in some baseline questionnaires, provide sociodemographic information and receive a private login to access the program in order to start the intervention. After completing the second, fourth and eight intervention session participants will fill in the same and other psychological questionnaires.

Throughout the intervention, the investigators will frequently monitor patient's progress and potential worsening of depressive and anxiety symptoms. The investigating team will be particularly attentive to suicidal ideation. Patients identified with suicidal thoughts will be immediately contacted by the study team and advised to an appropriate course of action. Moreover, in all online pages of the "Willkommen Mutterglück" intervention participants can find an SOS button, providing contact information of emergency psychiatric units and suicide hotlines.

During the online intervention, participants will be contacted three times by telephone by coaches (psychotherapists in training). The content of coaching calls will adhere to a manualized script with defined aims of reviewing patient's progress, problem solving, encourage skill acquisition and introducing topics in upcoming sessions. Coaches will be trained with a specific manual developed by the investigation team. Training for the coaching role will involve reading the coach manual, knowledge of the program content and explanations from a senior researcher about the role and the tasks involved.

Importance: In view of the substantial challenge posed by the global burden of depression and anxiety, it is relevant to investigate how a disorder, which is a leading cause of disability worldwide, may affect mothers and mothers-to-be. Pregnant and postpartum women are often reluctant to take medication due to concerns about breast milk transmission or potential side effects. Therefore, non-pharmacologic interventions are a desirable first-line treatment option for this population. Given that despite frequent interactions with health workers during pregnancy and postpartum, rates of treatment for perinatal disorders are low, online therapy may be a viable treatment alternative. The planned longitudinal study is relevant in investigating the feasibility of an interactive CBT online intervention including minimal psychotherapist involvement and tailored specifically for this population. At the same time, it assesses the effectiveness of it in reducing depression and/or anxiety in pregnant and postpartum women. The results will help to better understand if an intervention (online program with coaching) with few barriers (e.g. no travel, no childcare costs, reduced stigma), may serve as an effective treatment option for pregnant and postpartum women who experience significant stigma or are underresourced in their local community.

Inclusion Criteria:

• pregnant women or women who had given birth in the last year
• between 18 and 45 years old
• minor to moderate depression and/or generalised anxiety disorder
• fluent in German
• having a computer, laptop or handheld device with internet access

Exclusion Criteria:

• women with a severe medical disorder or a severe psychological disorder such as psychosis, drug addiction and other substance abuse
• women taking psychotropic medication
• women with current suicidality
• women who are currently receiving psychological treatment for depression or anxiety