Tackling Depression and Anxiety: A Working Memory Intervention

Anxiety and depression are both associated with impairments in executive functions, including working memory (WM) which is needed to maintain and manipulate goal-relevant information. Due to these WM impairments anxious and depressed individuals have difficulties inhibiting and shifting from irrelevant (negative) information and updating goal relevant information. This study explored whether training WM decreases these impairments and reduces clinical symptoms and rumination. Eighty-four individuals diagnosed with major depression and forty-nine individuals with an anxiety diagnosis executed WM or control tasks three times a week, during four weeks. Before, after training and at a two months follow-up measurement depression and anxiety symptoms, WM capacity and rumination behaviour were assessed. Training WM did only result in a reduction of anxiety symptoms in the depression group. These findings are inconsistent with promising results of individual studies showing training WM result in an enlarged WM capacity and a decrease of psychopathological symptoms. However, our results are in line with recent meta-analyses and reviews which show that WM training do not lead to generalized effects and therefore, doubt the clinical relevance of WM training programs.

The WM consisted of two tasks; the Number-letter task (Rogers & Monsell, 1995) and an Updating task. The Number-letter task trains the ability to shift between task relevant stimuli. Participants need to shift between four categories. In the Updating task participants receive a set of three words in which they have to compare the two consecutive words on emotional valence (positive or negative) to train their updating skills. Participants executed the training three times a week during four weeks.

Both the WM and the placebo training consisted of two tasks; the Number-letter task (Rogers & Monsell, 1995) and an Updating task. To prevent training WM the placebo training was a simplified version of the Number-letter task in which shifting was not required. In the Updating task the placebo group only had to count the number of positive or negative words. Participants executed the training three times a week during four weeks.

Beck Depression Inventory Second Edition (BDI-II) score change between pre and post training and at follow-up measurement (2 months after post measurement)

Pre training (baseline), post training (4 weeks after baseline, training starts 1 day after baseline) and follow-up (2 months after post-test)

State-Trait Anxiety Inventory (STAI) scores change from pre to post training and to follow up measurement (2 months after post measurement)

Pre training (baseline), post training (4 weeks after baseline, training starts 1 day after baseline) and follow-up (2 months after post-test)

Ruminative Response Scale (RRS) score change between pre and post training and follow up (two months after post)

Pre training (baseline), post training (4 weeks after baseline, training starts 1 day after baseline) and follow-up (2 months after post-test)

Symmetry Span score change between pre and post training and at follow-up measurement (2 months after post measurement)

Pre training (baseline), post training (4 weeks after baseline, training starts 1 day after baseline) and follow-up (2 months after post-test)

Internal shift task score change between pre and post training and at follow-up measurement (2 months after post measurement)

Pre training (baseline), post training (4 weeks after baseline, training starts 1 day after baseline) and follow-up (2 months after post-test)

Inclusion Criteria: Major depression diagnosis Anxiety disorder diagnosis Exclusion Criteria: Current psychosis Current substance dependency