By Christian Jarrett

Heralded as a revolution in mental health care – a cost-effective way to deliver evidence-based psychological help to large numbers – low-intensity Cognitive Behavioural Therapy (CBT) is recommended by NICE, the independent health advisory body in England and Wales, for mild to moderate depression and anxiety and is a key part of the “Improving Access to Psychological Therapies” programme in those countries. Prior studies into its effectiveness have been promising. However, little research has looked at whether the benefits last.

A new study in Behaviour Research and Therapy has done that, following a cohort of people with depression and anxiety over time. Disappointingly, the team led by Shehzad Ali at the University of York, found that after completing low-intensity CBT, more than one in two service users had relapsed within 12 months.

Low-intensity CBT is based on the same principles as full or high-intensity CBT – clients reflect on and strive to change their habits of thought that could be contributing to their mental distress, and they also learn coping strategies and other skills. However, it’s delivered in such a way as to reduce the need for extended one-on-one time with a qualified psychotherapist. It typically incorporates self-help books and internet exercises, usually completed under the guidance of a “well-being practitioner” or coach who is trained to follow a highly structured programme rather than having any formal psychotherapy training.

To test the longer term outcomes for low-intensity CBT, Ali and his colleagues recruited hundreds of people at a primary care service in West Yorkshire in England. The participants were diagnosed with depression or anxiety, or both, and had enrolled in low-intensity CBT. Some dropped out prematurely and were not included in further analysis.

For current purposes, the researchers were interested in the 439 participants who had recovered during their low-intensity CBT (improvements in their symptoms meant they no longer met the diagnosis for anxiety or depression) and who had ended their course of treatment in agreement with their practitioner or coach – on average this was after seven contacts with their practitioner, including the initial assessment. For comparison, high-intensity CBT with a psychotherapist can last up to 20 sessions.

After finishing their low-intensity CBT, the recovered participants (average age 41, 60 per cent were female, over 90 per cent were white British) completed monthly questionnaires that measured their levels of anxiety and depression symptoms. As time went on, an increasing proportion of the participants showed evidence of having relapsed – that is, their symptoms had deteriorated to a point that suggested they would likely be diagnosed as having anxiety or depression again. By twelve months after the end of their low-intensity CBT, nearly 53 per cent had relapsed; half of these relapses had occurred within two months, 80 per cent within six months (for comparison, a meta-analysis of high-intensity CBT found that 29 per cent of recovered clients with depression had relapsed within 12 months, which is a better outcome than for patients who stop taking anti-depressants) .

Is it possible to predict who is likely to relapse? In the current study, recovered participants who still showed some symptoms of depression at the end of their course of low-intensity CBT (but not enough to justify a diagnosis) were far more likely to relapse over the ensuing year. Residual anxiety symptoms were not predictive in this way. The finding for residual depression symptoms suggests many low-intensity CBT users would benefit from some kind of on-going after care, such as booster sessions or other lower-intensity support.

“It seems hasty to consider patients ‘recovered’ at the point of discharge without assessing full remission symptoms over a longer period,” Ali and his colleagues concluded. “It could be argued that many of the relapse cases in this study actually had partial (rather than full) remission at the time of treatment completion, and thus never actually ‘recovered'”.

The findings from this study will fuel the fears of some experts that low-intensity CBT is a form of false economising. It may be quick and cheap but the results suggest that many people are being sent on their way before they are fully recovered.

One counter to that argument is that prior to the roll out of low-intensity CBT, many of the kinds of people who took part in this research (i.e. people with mild to moderate mental health problems) would have received no treatment at all or given powerful drugs. They might have spent months or years on a waiting list for a psychotherapist, during which time their problems may well have worsened. Another point to bear in mind was that this research was conducted in just one service in England, and more research is needed in other areas.

“It is clear that relapse prevention is an overlooked aspect of routine stepped care in Improving Access to Psychological Therapies services and an important area for further policy and research developments,” the researchers said.

—How durable is the effect of low intensity CBT for depression and anxiety? Remission and relapse in a longitudinal cohort study

Christian Jarrett (@Psych_Writer) is Editor of BPS Research Digest