This research will investigate the neuropsychological mechanisms underlying the eight-week Mindfulness-based Cognitive Therapy (MBCT) programme.

Participants in remission from depression will be seen pre- and post-MBCT to assess the underlying neuropsychological mechanisms. All will be followed-up over 12 months to assess the relationship of these neuropsychological changes with relapse risk.

The research will focus primarily on changes in self-compassion, rumination, attention and structural brain changes, with secondary focus on other mechanisms of emotional processing and memory.

There will be three groups in total.

• The first group will take 36 participants in remission from major depression (rMDD) through the 8 week MBCT program.
• A control group of 36 rMDD participants will not receive the intervention.
• A group of never depressed healthy control participants will also be recruited.

Research visits for participants not undergoing MBCT will be separated by an 8 week gap.

All participants will be seen before and after the 8 weeks for completion of neuropsychological assessments and questionnaires.

rMDD participants will be followed up over the following 12 months to identify any predictors of relapse.

Inclusion Criteria:

Participants with remitted depression (rMDD):

• At least two previous episodes of DSM-IV major depression in adulthood, diagnosed using the Mini International Neuropsychiatric Interview (M.I.N.I).
• Full or partial remission for at least three months with two depressive episodes within the last five years.
• A score of less than or equal to 12 on the Montgomery Asberg Depression Rating Scale (MADRS) mood assessment.
• If on medication, no recent or planned major changes

Healthy volunteers:

• In good psychological health screened with the M.I.N.I

All participants:

• in good physical health (to reduce risk of confounding physical health problems).
• sufficiently fluent in English to ensure valid understanding and completion of the tasks.
• minimum I.Q level of 80 to ensure sufficient understanding of the neurocognitive tasks administered.
• colour vision and acuity within normal/corrected to normal limits.

Exclusion criteria:

• Any current mental health diagnosis (DSM-IV diagnosis including current major depression, bipolar disorder, psychosis, Obsessive Compulsive Disorder (OCD), substance abuse or dependence, eating disorders)
• Physical health or neurological disorders that might interfere with the interpretation of the tasks, including a history of significant head injury.
• In addition healthy volunteers will be without a history mental health disorders (DSM-IV)
• Current or previous experience of mindfulness-based treatments or extensive cognitive behavioural treatment, or planned participation in psychological treatments during the key time for the study (between pre and post visits).
• Planned major alteration in drug treatment for depression between pre and post visits.