Although substantial progress has been made in the treatment of many chronic conditions in psychiatry, recurrent depression continues to cause significant disability and human suffering. An outstanding challenge remains developing cost-effective approaches to prevent depression from turning into a recurrent, relapsing condition.1 The current mainstay approach to preventing depressive relapse is maintenance antidepressants and many patient groups have advocated for accessible psychosocial approaches to help people at risk for depression. Mindfulness-based cognitive therapy (MBCT) was developed by Zindel Segal, one of us (J.M.G.W.) and John Teasdale, with the aim of helping people vulnerable to repeated episodes of depression stay well in the long term.2 The intention was to use a psychological understanding of depressive relapse to develop a targeted approach to relapse prevention for people with recurrent depression.
So what is the theoretical rationale for MBCT? During an episode of depression, low mood coexists with negative thinking, other painful emotions and unpleasant body sensations. Once the episode is past, and mood has returned to normal, the constellation of negative thinking, emotions and body sensations tends to go into abeyance. However, there is evidence that, even after recovery from an episode of depression, people remain vulnerable in that a relatively small change in mood can result in a large escalation of negative thoughts, including self-judgement (such as ‘I am worthless’), negative views of experience (such as ‘Everything is just too difficult’) and hopelessness (such as ‘There is nothing I can do to escape my situation’). Negative thoughts are accompanied by other powerful emotions in addition to low mood (e.g. anxiety, guilt, anger, frustration, shame), and by physical symptoms and body sensations such as weakness, fatigue, tension and pain. These thoughts and feelings may seem overwhelming, not least because they can seem out of proportion to the trigger situation. Individuals who thought they had recovered may feel as if now they are ‘back to square one’, and fear that this is the start of an inevitable slide into depression. In an attempt to understand what is going on and to find a solution, they begin to analyse their experience, and may end up inside a constantly circling ruminative loop, plagued by questions such as ‘What has gone wrong?’, ‘Why is this happening again?’ and ‘Where will it all end?’ Ironically, when people try to think their way out of depression in this ruminative way, it may have the effect of prolonging and deepening the mood disturbance.
In summary, there is good evidence that (a) how easily the constellation of negative thoughts and feelings remain ready for activation is a marker for vulnerability to relapse and recurrence, (b) psychological interventions can reduce this reactivity, and (c) reductions in cognitive reactivity are associated with lower risk for depressive relapse.3