A clinical replication series to investigate if EMDR has the potential to treat clients with long term depression, its acceptability to them and possible mechanisms of change

Depression is one of the world's leading causes of disability. Current methods used to treat it, both medication and psychotherapy, are effective for some but not all; new approaches need to be developed to complement the ones already available. This need is particularly acute for chronic and recurrent depression. A single case experimental design with replications was implemented for a preparatory investigation into the potential of Eye Movement Desensitisation and Reprocessing (EMDR) to treat long term depression. Ten people with recurrent and/or chronic depression were recruited from primary care mental health services and received Standard Protocol EMDR for a maximum of 20 sessions. Levels of depression and social functioning were measured before and after treatment and at follow up, clients also rated their mood each day. Before and after treatment the participants recorded their target memories whilst recording psychophysiological parameters and after treatment they were interviewed about their experience of EMDR. Eight people engaged with the treatment, seven of these had clinically significant and statistically reliable improvement on the Hamilton Rating Scale for Depression and this improvement was linked to the progress of treatment. Heart rate variability was significantly reduced indicating a less withdrawn parasympathetic nervous system. Interviews elicited a highly favourable opinion of EMDR from the participants including all participants saying they would recommend it to others. EMDR has shown potential to be an effective treatment for depression. This phase I study has provided a platform for a phase II pilot trial and phase III randomised controlled trials to gauge efficacy and effect size in a larger sample. This study's results are consistent with the working memory taxation theory of mechanism of change in EMDR.