[Definition and Decision-Making in the Determination and Detection of Side Effects of Psychotherapy]

There is no generally accepted definition of side effects, which causes problems in research and clinical practice. Not even the distinction between main and side effects is always clear. Several judgments are needed in the assessment of side effects. First, it must be decided where to look for unwanted events. Events are defined by the temporal contingency with the treatment. Second, it must be made a judgement whether it is an unwanted or wanted event. Everything is unwanted, which would be problematic, if it would be possible to do without it. Thirdly, a causal relationship with the treatment must be made plausible. Fourthly, a decision must be made that the treatment has been adequate and not malpractice or other unethical behavior. Side effects can be defined as unwanted consequences of correct treatment. The relevance of side effects is depending on severity and duration.