When someone is offered therapy for depression, the approach on offer often depends on where they were referred rather than on any clear evidence that one method suits them better. A trial by Malkomsen and colleagues compared two of the main options directly.
One hundred patients attending psychiatric outpatient clinics were randomly assigned to either cognitive behavioural therapy, which focuses on the thoughts and behaviours that maintain low mood, or short-term psychodynamic psychotherapy, which works with recurring emotional patterns and relationships. The CBT group was offered 16 weekly sessions followed by 3 monthly booster sessions. The psychodynamic group was offered 28 weekly sessions. Unusually, the trial accepted people who were taking antidepressants or had strong suicidal thoughts, so the group looked more like the people clinicians actually see.
Neither therapy came out ahead on any measure. Both produced large improvements in depression scores, and moderate to large improvements in work, social functioning and general wellbeing. Around three-quarters of patients improved reliably on each of the two main depression measures. A small number, 6% on one measure and 10% on the other, got reliably worse.
Short-term therapy does not work for everyone, and that is worth knowing at the outset. If depression is affecting your life, talking to a psychologist about the options is a reasonable first step.
Why the comparison was worth making
Cognitive behavioural therapy and short-term psychodynamic psychotherapy are both used for major depressive disorder, and both have supporting evidence. What has been in shorter supply is head-to-head research with a low risk of bias, conducted in the kind of clinic where most people are actually treated.
The two approaches differ in what they treat as the engine of depression. Cognitive behavioural therapy works on current thinking patterns and behaviour, including withdrawal from activity and the habit of interpreting events in self-critical ways. Short-term psychodynamic psychotherapy works on recurring emotional and relational patterns, including those a person is not fully aware of, and on how these play out in present relationships.
What the study did
One hundred patients with major depressive disorder in psychiatric outpatient clinics were randomly allocated to one of the two treatments. Those in the cognitive behavioural arm were offered 16 weekly sessions followed by 3 monthly booster sessions. Those in the psychodynamic arm were offered 28 weekly sessions.
Inclusion criteria were deliberately broad. Participants using antidepressants were eligible, as were those with strong suicidal ideation. Trials often exclude both groups, which produces cleaner data and a sample less like the people sitting in a waiting room. Widening entry costs some statistical tidiness and buys relevance.
The primary outcomes were the Hamilton Depression Rating Scale, completed by a clinician, and the Beck Depression Inventory-II, completed by the patient. Using both matters, since a clinician's judgement and a person's own account of their mood do not always move together. Secondary measures covered work and social adjustment, anxiety symptoms, overall functioning and general health.
What it found
There were no significant differences between the two treatments on any measure. Within each group, improvement on the primary depression measures was large by the usual convention for effect sizes, where 0.2 is small, 0.5 moderate and 0.8 large. Improvement on the secondary measures was moderate to large.
The researchers also applied the reliable change index, a method that asks whether an individual's change is bigger than the measurement error of the instrument. It is a more demanding and more honest test than a group average, because it counts people rather than shifts in a mean. On this basis, 79% of patients reliably improved on the clinician-rated scale and 76% on the self-report scale. The same method identified deterioration: 6% got reliably worse on the first measure and 10% on the second.
What follows from it
Two findings sit alongside each other. Both therapies work, and both work about equally well in ordinary outpatient conditions, including with people taking medication or experiencing serious suicidal thoughts. That widens what can reasonably be offered and makes fit, preference and availability legitimate grounds for choosing between them.
The second finding is less comfortable and the authors state it plainly. Not everyone responds to short-term treatment. A minority were reliably worse at the end, which is a reason to track progress during therapy rather than assume a course will help simply because it has been started.
This was a single trial of one hundred patients, so it is a contribution to the evidence rather than the last word. If you are weighing up therapy for depression, or a course of therapy has not helped as you hoped, a psychologist can help you think through what to try next.