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’.
Such effects are not so surprising when you consider that CBT can involve exposure therapy (ie – gradual exposure to situations that provoke anxiety) – discussing and focusing on one’s problems – reflecting on the sources of one’s stress such as difficult relationships – frustration at lack of progress and feelings of growing dependency on a therapist’s support.
The longer that a client had been in therapy the more likely she was to have experienced one or more side effects.
Also and against expectations clients with milder symptoms were more likely to experience side effects – perhaps because more serious symptoms mask such effects.
Interestingly before the structured interviews the therapists were asked to say off the top of their heads whether they felt that their client had had any unwanted effects – in this case 74 per cent said they had not.
Often it was only when prompted to think through the different examples of potential side effects that therapists became aware of their prevalence.
This chimes with earlier research that’s documented the biases which can lead therapists to believe that therapy has been successful when it hasn’t.