The structured nature of cognitive behavioural therapy (CBT) and its clearly defined principles (based on the links between thoughts, feelings and behaviours) make it relatively easy to train practitioners, ensure standardised delivery and measure outcomes. Consequently, CBT has revolutionised mental-health care, allowing psychologists to alchemise therapy from an art into a science. For many mental-health conditions, there is now considerable evidence that CBT is as, or more, effective than drug treatments. Yet, just like any form of psychotherapy, CBT is not without the risk of unwanted adverse effects.
A recent paper in Cognitive Therapy and Research outlines the nature and prevalence of these unwanted effects, based on structured interviews with 100 CBT-trained psychotherapists. ‘This is what therapists should know about when informing their patients about the upcoming merits and risks of treatment,’ write Marie-Luise Schermuly-Haupt of the Charité University of Medicine in Berlin and her colleagues.
The researchers asked each CBT therapist (78 per cent of whom were female, average age 32, with an average of five years’ experience) to recall their most recent client who had taken part in at least 10 sessions of CBT. The chosen clients mostly had diagnoses of depression, anxiety or personality disorder, in the mild to moderate range.
The interviewer – an experienced clinical psychologist trained in CBT – followed the checklist of unwanted events and adverse treatment outcomes, asking each therapist whether the client had experienced any of 17 possible unwanted effects from therapy, such as deterioration, new symptoms, distress, strains in family relations or stigma.
The therapists reported an average of 3.7 unwanted events per client. Based on the therapists’ descriptions, the interviewer then rated the likelihood of each unwanted event being directly attributable to the therapeutic process – making it a true side effect (only those rated as ‘definitely related to treatment’ were categorised as such).
Following this process, the researchers estimated that 43 per cent of clients had experienced at least one unwanted side effect from CBT, equating to an average of 0.57 per client (one client had four, the maximum allowed by the research methodology): most often distress, deterioration and strains in family relations. More than 40 per cent of side effects were rated as severe or very severe, and more than a quarter lasted weeks or months, though the majority were mild or moderate and transient. ‘Psychotherapy is not harmless,’ the researchers said. There was no evidence that any of the side effects were due to unethical practice.
Examples of severe side effects included: ‘suicidality, breakups, negative feedback from family members, withdrawal from relatives, feelings of shame and guilt, or intensive crying and emotional disturbance during sessions’.