A simple and inexpensive psychotherapy or talking therapy known as behavioural activation (BA) is as effective at treating depression in adults as the gold-standard cognitive behavioural therapy (CBT), and can be delivered by non-specialist staff with minimal training at far less cost, according to new research published in The Lancet.

With long waiting lists and limited access to services, many people who need CBT for depression cannot get treatment. The findings from this new study - one of the largest trials of psychological treatment for depression to date - suggest that behavioural activation therapy could be delivered by junior mental health workers, leading to considerable savings for the NHS and other health services.

"Our findings challenge the dominance of CBT as the leading evidence-based psychological therapy for depression", says David Richards, lead author and Professor of Mental Health Services Research at the University of Exeter, UK. "Behavioural activation should be a front-line treatment for depression in the UK and has enormous potential to improve reach and access to psychological therapy worldwide."

Depression is a common mental health disorder affecting around 350 million people worldwide. Untreated depression is expected to cost the global economy US$5.36 trillion between 2011 and 2030. Currently, talking therapies like CBT are delivered by specialist clinicians and therapists who are expensive to train and employ. In many countries, access is limited to people who can afford to pay, or those with health insurance, and waiting lists can be long. For example, in England, 1 in 10 people have been waiting over a year to receive talking therapy, whilst in the USA, only about a quarter of people with depression have received any type of psychological therapy in the last 12 months.

Until now, the UK National Institute for Health and Clinical Excellence (NICE) has said there is insufficient evidence to recommend behavioural activation as a first-line treatment in clinical guidelines, and has called for a large non-inferiority study to establish whether behavioural activation is an effective alternative to CBT for treating depression.

The Cost and Outcome of Behavioural Activation versus Cognitive Behavioural Therapy for Depression (COBRA) trial recruited 440 adults with depression from primary care and psychological therapy services in three areas of England. Participants were randomly assigned to receive either a maximum of 20 sessions of behavioural activation treatment delivered by junior mental health workers [3] (221 participants), or CBT delivered by experienced psychological therapists (219). Between 20-30% of participants in each group did not attend the minimum number of 8 therapy sessions or dropped out, a common problem in psychological therapy services, and were not included in the analysis.

"Behavioural activation is an 'outside in' treatment that focuses on helping people with depression to change the way they act. The treatment helps people make the link between their behaviour and their mood. Therapists help people to seek out and experience more positive situations in their lives. The treatment also helps people deal with difficult situations and helps them find alternatives to unhelpful habitual behaviours," explains Professor Richards. "In contrast, CBT is an 'inside out' treatment where therapists focus on the way a person thinks. Therapists help people to identify and challenge their thoughts and beliefs about themselves, the world, and their future. CBT helps people to identify and modify negative thoughts and the beliefs that give rise to them."

One year after the start of treatment, behavioural activation was found to be non-inferior (not worse than) CBT, with around two-thirds of participants in both groups reporting at least a 50% reduction in depressive symptoms (tables 2 and 3). Participants in both groups also reported similar numbers of depression free days and anxiety diagnoses, and were equally likely to experience remission. Three participants receiving behavioural activation and eight receiving CBT reported depression-related, but not treatment-related, serious adverse events (self harm and overdose).

Importantly, the average intervention costs were significantly lower for behavioural activation than CBT (£974.81 vs £1235.23 per person); amounting to a 20% financial saving for health care systems (table 4). Additionally, cost-effectiveness analysis showed that behavioural activation is highly cost-effective and affordable compared with CBT, mainly due to the low cost of non-specialist mental health providers.

According to Professor Richards, "Our findings indicate that health services worldwide, both rich and poor, could reduce the need for costly professional training and infrastructure, reduce waiting times, and increase the availability of psychological therapies. However, more work still needs to be done to find ways to effectively treat up to a third of people with depression who do not respond to CBT or behavioural activation."

Writing in a linked Comment, Dr Jonathan Kanter from the University of Washington, Seattle, USA, and Dr Ajeng Puspitasari from Indiana University, Indiana, USA, say, "Now that we have support for BA as a treatment that is clinically effective and cost-effective, we can shift our efforts to focus on what is necessary to produce sustainable large-scale BA implementation across diverse geographical and cultural settings."

They add, "Substantial obstacles to successful international dissemination and implementation of any evidence-based practice exist at multiple provider, patient, organisational, and sociopolitical levels...Common obstacles include lack of training and support for providers, patients' low acceptability of and stigma towards treatment, organisational climates and cultures that are incompatible with evidence-based practices, and an absence of governmental policies and support for mental health service delivery. BA is a promising treatment to consider in international research efforts to overcome these obstacles."