Background: Major depressive Disorder (MDD) is a severe mental disorder associated with considerable disability and high costs. Over the last decades, various psychotherapies for MDD have been developed and researched, among others Behavioral Activation (BA) and Metacognitive Therapy (MCT). MCT and BA target different maintaining factors of MDD and have not been compared to date. The PRO*MDD randomized controlled trial will compare MCT and BA in the routine clinical setting of an outpatient clinic.Methods and Design: We aim to recruit 128 MDD patients, who will be randomly assigned to either MCT or BA. In both conditions, patients will receive one individual therapy session and one group therapy session per week for a maximum of 6 months. Assessments will take place at baseline, pre-treatment, mid-treatment, post-treatment as well as at 12, 18, and 30 months after start of treatment as follow-up. The primary outcome is reduction of depression severity assessed with the Hamilton Rating Scale for Depression; secondary outcomes address quality of life, psychosocial functioning and participation as well as comorbidity.Discussion: The PRO*MDD study is the first randomized controlled trial to compare the effectiveness of MCT and BA. The outcome of this trial will increase our knowledge on the effectiveness and applicability of both treatment modalities and therefore contribute to the improvement of treatment for depressive patients.Ethics and dissemination: The study has been reviewed and approved on 11 August 2016 by the Ethics Committee of the Lübeck University (reference number: 16–176). The results will be discussed through peer-reviewed publications.Trial registration: German Clinical Trials Register DRKS-ID: DRKS00011536 (retrospectively registered)

In order to study the changing relevance of stimulus features in time and space, we used a task with rapid serial presentation of two stimulus streams where two targets (“T1” and “T2”) had to be distinguished from background stimuli and where the difficult T2 distinction was impeded by background stimuli presented before T1 that resemble T2 (“lures”). Such lures might actually have dual characteristics: Their capturing attention might interfere with target identification, whereas their similarity to T2 might result in positive priming. To test this idea here, T2 was a blue digit among black letters, and lures resembled T2 either by alphanumeric category (black digits) or by salience (blue letters). Same-category lures were expected to prime T2 identification whereas salient lures would impede T2 identification. Results confirmed these predictions, yet the precise pattern of results did not fit our conceptual framework. To account for this pattern, we speculate that lures serve to confuse participants about the order of events, and the major factor distinguishing color lures and digit lures is their confusability with T2. Mechanisms of effects were additionally explored by measuring event-related EEG potentials. Consistent with the assumption that they attract more attention, color lures evoked larger N2pc than digit lures and affected the ensuing T1-evoked N2pc. T2-evoked N2pc was indistinguishably reduced by all kinds of preceding lures, though. Lure-evoked mesio-frontal negativity increased from first to third lures both with digit and color lures and, thereby, might have reflected expectancy for T1.