The Modulatory Role of Communicated Treatment Rationale on Treatment Expectation Effects in Depression.

Depression is described as a brain disorder and the role of monoamine, brain structures, and brain functions are reported as central mechanisms of relevance for its etiology and treatment. Biological processes are illustrated using typical charts and visualizations. Psychological influences are mentioned, but only as a byproduct of the disorder.

Depression is described as a psychological disorder resulting from emotion regulation deficits. The suppression of emotions receives a special role in explaining depression. The psychological processes are illustrated using charts and visualizations. Biological aspects are mentioned, but only as a byproduct of the disorder.

"The active placebo pill does not have direct effects on the brain. Buscopan (butylscopolamine, 10 mg daily, 1 pill in the morning) does not cross the blood-brain barrier, yet induces some smaller side effects that resemble those of antidepressants (e.g., mouth dryness, fatigue, nausea). Treatment duration is 4 weeks. The rationale is briefly explained to participants as stimulating the biological balance in humans with depression, using a well-tolerated drug similar to Buscopan, which is well-known from pain treatments."

"Emotional writing consists of writing about emotional experiences (4 sessions, one per week, 30 minutes each). The study instructor will be present displaying standard psychotherapeutic attitudes but will not read the participant's notes. The rationale for this treatment is briefly explained as improving the dealing with emotions to achieve a psychological balance in humans with depression."