A study led by Dr. Schermuly-Haupt of the Psychosomatic Rehabilitation Research Group at Charité University Medicine Berlin examines the prevalence of side effects for Cognitive-Behavioral Therapy (CBT). The researchers, whose results were published in Cognitive Therapy and Research, found that 43% of CBT patients in their sample experienced side effects, which they define as “negative reactions to an appropriately delivered treatment.”

“Knowledge about the side eﬀect profile [of psychotherapy] can improve early recognition of side effects, safeguard patients, and enhance therapy outcome,” the researchers write.

Researchers have long recognized that psychotherapy has positive as well as negative consequences. Estimates of side effect (SE) rates for psychotherapy vary from 5% to 20% of cases. One such side effect — deterioration of symptoms due to therapy — has been found to occur in 3 to 10% of patients. Psychological distress and marital/family conflict are two common side effects of treatment; others include the appearance of new symptoms, suicidality, stigmatization, and tension or changes in a patient’s social relationships.

Despite historical recognition of psychotherapy’s side effects, there is currently little data on their features and rate of occurrence. Dr. Schermuly-Haupt and colleagues sought to address this gap. They interviewed one hundred CBT therapists, asking them to describe “unwanted events” (UEs) experienced by a recent patient who had undergone 10 or more sessions of CBT.

Therapists were prompted to distinguish between unwanted events (i.e., any unwanted event that occurs during therapy, which may or may not be related to the therapy), adverse treatment reactions (i.e., an unwanted event related to treatment), and side effects (i.e. an unwanted event related to treatment that met “professional standards”) through the use of an Unwanted Events-Adverse Treatment Reactions Checklist, which differentiates between these treatment reaction categories.

The researchers found a curious discrepancy between the percentages of side effects identified by psychotherapists who were first asked for a “spontaneous report,” versus the percentage later identified during interviews when the various categories of unwanted events were “systematically evoke[d]” through use of the checklist. Initially, 74% of therapists stated that they didn’t know of any UEs or SEs that had occurred during treatment.

After the structured interview, however, therapists reported that 43% of patients experienced one or more SE (Average .57, SD = .81). This difference in reported side effects may point to a blind spot on the part of psychotherapists, which perhaps owes to difficulty recognizing one’s ability to harm, as well as a lack of training and awareness about psychotherapy’s adverse side effects.

The most commonly reported side effects included “negative well-being/distress,” “deterioration of symptoms,” and “strains in family relations.” According to qualitative data, examples of “negative well-being/distress” included crying uncontrollably in session, discomfort, and fear when engaging in interventions in session (e.g., exposure activities, role plays), difficulty discussing specific topics, and strong feelings experienced in response to the therapist (e.g. anger, tension, stress, and anxiety).

Examples of family strain that emerged as a result of treatment included a spouse who was distressed after his wife became less attentive and took more time for herself after being in therapy and a client who felt guilt and sadness after choosing to distance herself from a parent.

The authors note that there is some debate regarding whether “ordinary reactions” to CBT, such as the distress reactions and changes in patients’ social relationships described above, should be characterized as side effects, particularly since they may be essential to successful treatment outcomes. They argue that even though these responses “may be unavoidable, justified, or even needed or intended,” they should nevertheless be categorized as side effects. These side effects, although “unavoidable” and even “intended,” should be studied and should serve as motivation to develop treatments that “are better tolerated,” they write.

The authors also note that although the majority of the side effects identified in their study were rated as mild to moderate (59.6%) and not lasting (89.6%), over 40% of side effects were classified as severe or very severe, and 8.8% were persistent. Reflecting on these findings, they conclude, “Psychotherapy is not harmless.”

The study has several limitations. As psychotherapists reported side effects, reports may have been influenced by therapist bias; the authors suggest that future studies use a blend of stories from patients, therapists, and outside interviewers. The study’s sample was composed of patients with various diagnoses, and as such, results would likely be different in a more homogenous sample, or with a different form of therapy. Additionally, as approximately half of the patients whose cases were reported on in the study were taking psychotropic drugs, and it is thus impossible to rule out the effect of medication on the observed side effects.

The authors hope that the results of their study will increase psychotherapists’ awareness of treatment side effects and that this will contribute to improved care. In alignment with the recent call for an enhanced psychotherapy informed consent process, the authors also state that their data can be used to strengthen informed consent in psychotherapy, as well as to support “risk monitoring” throughout treatment.

****

Schermuly-Haupt, M. L., Linden, M., & Rush, A. J. (2018). Unwanted Events and Side Effects in Cognitive Behavior Therapy. Cognitive Therapy and Research, 42(3), 219-229. (Link)