A 440-person depression trial where the less-trained therapists did just as well
The 2016 COBRA trial in The Lancet randomized 440 adults with depression to behavioral activation or CBT. Junior workers matched therapists at 12 months.
In this article10 sections
Ten junior mental health workers delivered behavioral activation (BA) in the COBRA trial. They averaged 18 months of mental health experience, they had no professional training in psychological therapies, and at the 12-month mark their patients scored 8.4 on the PHQ-9 depression questionnaire. Patients treated by CBT therapists also scored 8.4.
That is the short answer to a question that matters if you are stuck and wondering whether a plain, structured approach to doing things can be enough. In Richards et al. (2016, The Lancet, 388(10047), 871-880), a therapy built around monitoring and scheduling activity, handed to junior staff with a manual, was no worse than CBT delivered by qualified therapists. It is a result about a clinical treatment for diagnosed depression, and the last section covers how far it stretches.
Who was in it
The trial randomized 440 adults between September 2012 and April 2014: 221 to BA and 219 to cognitive behavioral therapy (CBT). Everyone met DSM-IV criteria for major depressive disorder and was recruited from primary care and psychological therapy services in Devon, Durham and Leeds. People were excluded if they were already receiving psychological therapy, were dependent on alcohol or drugs, had bipolar disorder or psychotic symptoms, or had been acutely suicidal or attempted suicide in the previous two months. Treatment was open label, since nobody can hide which therapy they are getting, but the staff who assessed outcomes were masked.
What the junior workers actually did
The BA manual covered five jobs, as the authors list them: identifying depressed behaviors, analyzing what sets them off and what follows, monitoring activities, developing alternative goal-oriented behaviors, and scheduling activities. There was also work on responses to rumination. Up to 20 sessions were offered over 16 weeks, with four optional boosters.
The CBT arm worked on beliefs. Therapists helped participants identify and test negative thoughts, which is a different job from planning Tuesday’s walk. The workers in both arms got 60 minutes of clinical supervision every two weeks from experienced NHS psychological therapists.
The CBT therapists were not veterans either. They averaged 22 months since qualifying, against 18 months of mental health experience for the BA workers. One CBT therapist was removed early for not meeting the competency standard. The BA workers were graduates trained to deliver guided self-help, without a professional qualification in mental health.
The result, and what “non-inferior” means
At 12 months the mean PHQ-9 was 8.4 in both arms in the main analysis (CBT SD 7.5, BA SD 7.0). The difference was 0.1 points, with a 95% confidence interval of -1.3 to 1.5, inside the pre-set margin of 1.9 points. In the per-protocol analysis, restricted to people who attended at least eight sessions, it was 7.9 for CBT and 7.8 for BA.
“Non-inferior” is a narrower claim than “equal”. It means BA could not be shown to be worse by more than the margin. Because the trial had no placebo or waiting-list arm, it does not tell you how far either therapy beat doing nothing. The authors also followed people to 18 months for the cost analysis, and the costs came out lower for BA: the intervention averaged £974.81 per participant against £1,235.23 for CBT, a difference of £262.29 (95% CI £143.19 to £381.40).
The number that is easy to skip
Of 440 participants, 135 (31%) completed fewer than eight sessions, and that group averaged about 2.5 sessions each. The rate was 33% in the BA arm and 28% in the CBT arm, and the authors describe it as a problem well known to routine psychological therapy services. Nearly a third of the people offered treatment had barely started it by the time the minimum dose was counted.
For a stuck stretch of ordinary life, that is probably the most transferable fact in the paper. The technique (write down what you do, schedule something, do it before the mood agrees) was simple enough for a graduate with a manual to teach. Getting people to the second and third appointment was the hard part.
What carries over
COBRA came a decade after the Dimidjian trial of 2006, which pitted scheduling against medication. Its added lesson is about delivery. Three pieces transfer without a therapist, and each is a workaround for waiting to feel ready: record what you did for a few days before changing anything, which is the monitoring step; put one activity at a fixed time before the day starts; and make it hard to skip silently, since skipping is what the attendance figures above show happening.
DontSnooze, an iOS alarm, applies that last piece to one slot of the day: the alarm asks for a short video of you awake, and the friends in your group can see whether it arrived (how it works). Nothing in COBRA tested friends as a substitute for a supervised worker, and I found no study testing that app against low mood, so treat it as a way to make the first scheduled action visible, not as treatment. For what a first action looks like at the lowest point, getting out of bed when depressed goes through it in steps.
Limits of the trial
The participants were diagnosed adults treated in three English regions, and complete 12-month data existed for 175 of 221 people in the BA arm and 189 of 219 in the CBT arm. Medication was not controlled. A manual-following junior worker with fortnightly supervision is a long way from a phone reminder. If low mood has lasted more than a couple of weeks or is making daily life hard, see a clinician; this is general information, not medical advice.
Three details the abstract skips
Did the COBRA trial include a group that got no treatment or a placebo?
No. Both arms received an active therapy, so the trial can say that BA (behavioral activation) was not worse than CBT, but it cannot say how either compared with doing nothing. The 1.9-point margin was set at half of the 3.8 PHQ-9 points by which earlier meta-analysis data showed BA beating control conditions.
Were antidepressants held constant across the two groups?
No. Medication use was one of three stratification variables used when assigning people (with severity and site), so the arms were balanced on it, but the authors say they could not quantify or control what medication contributed. Most participants on medication had been taking it for a considerable time before enrolling.
How much did the two kinds of worker cost?
The authors costed staff time from NHS pay bands. Band five, used for the junior workers, spanned 21,909 to 28,462 pounds a year in salary; band seven, used for the CBT therapists, spanned 31,383 to 41,373 pounds. Employer pension and insurance contributions, plus overheads, were added on top before the per-patient figures were calculated.