MS patients with depressive symptoms exhibit affective memory biases when verbal encoding strategies are suppressed

As many as 50% of multiple sclerosis (MS) patients experience clinical or subclinical depression. A voluminous literature has documented affective memory biases (AMB) among depressed individuals. Despite this, little is known regarding how depressive symptoms may affect MS patients' ability to recall positive and negative material. The present study employed an affective list-learning task that increased cognitive load and inhibited the use of higher order encoding strategies. The purpose of the study was twofold: to determine whether MS patients exhibit AMB and to examine whether subvocal repetition and other higher order encoding strategies are essential to the formation of AMB among people experiencing depression. Results indicated a strong relationship between depression and AMB in MS. The results are discussed in relation to existing biological research that indicates limbic and/or other subcortical systems may play a role in the formation of AMB.