Table 1 Brief information given to participants about internet-based interventions (adapted and translated from German)

• Cognitive behavioural therapy (CBT) has long been shown to be effective in reducing symptoms of depression and anxiety disorders. It explores the links between thoughts, emotions and behaviour, being a time-limited, structured approach used to treat several mental health disorders.

• CBT aims to help patients to understand their ways of thinking and behaving, and provides patients with the resources to alter their maladaptive cognitive and behavioural patterns. As a consequence, it alleviates patients’ distress. Due to its structured nature, CBT is the most widely researched and empirically supported psychotherapeutic method.

• Driven by advances in technology, for some years, there has been internet-based cognitive behavioural therapy (iCBT). iCBT is delivered through an online platform where patients log in regularly to a secure website, have access to online materials usually organized in 6–12 modules and go through the treatment protocol via audio and video lessons.

• iCBT can be delivered in sessions/themes comparable to face-to-face psychotherapy sessions. Patients can also receive homework assignments to be completed before the next module and fill out computer-administered questionnaires assessing their symptoms. iCBT programs are particularly easy to access, and patients are able to determine the pace at which they wish to complete them, which can improve learning and retention.

• Numerous studies have shown that particularly for depression and anxiety disorders, iCBT is effective in reducing symptoms in the general adult population and also in the postpartum population. The effects seem to be similar to face-to-face cognitive behavioural treatment.

• Improved effects have been observed especially in guided iCBT (e.g. psychotherapist/clinician support or coaching) for anxiety and depression. In a guided intervention, the patient is supported by a psychotherapist or coach when working through the online treatment protocol. The support given should be facilitative in nature. Interaction between patient and therapist can take place by telephone, email or any other communication method.

• In an unguided intervention, feedback is provided by the computer based on the patient’s achievements and there is no contact, personal or online, involved.

• Common disadvantages associated with both guided and unguided iCBT include: data security issues, high withdrawal rate, not applicable for all patients, failure to detect problems in the therapeutic process.

• The National Institute for Health and Care Excellence (NICE) guidelines actively suggest iCBT for women with mild to moderate depression or anxiety during the perinatal period. According to the NICE, iCBT could improve low treatment rates and increase privacy and anonymity while reducing stigma.