I think it is becoming clear that the serotonin reuptake blockers do not seem to be as significant in their impact directly on cognitive performance and cognitive function. There are short-term and long-term studies that may begin to give us some explanation, some based on the fact that the cognitive performance and cognitive function effects relate to the general efficacy of selective serotonin reuptake inhibitors (SSRIs).

The other piece is that there is a proportion of patients – probably small, but significant – for whom continued serotonin reuptake blockade may actually lead to some associated apathy and cognitive performance issues. That phenomenon, I think, is something that we’ve known about for some time, and I think it plays out in terms of long-term studies with SSRIs.

It is a very interesting range of cognitive dysfunctions that you see in patients with mood disorders and especially in the group of patients for whom depressive symptoms are getting better, but the cognitive performance is not. Those patients find themselves actually puzzled because their depression is improving, they are sleeping better, and their mood is better, but their ability to perform at work remains significantly impaired.

In the elderly, the possibility of concomitant cognitive impairments associated with vascular events and with dementias is real, and that is something that should be pursued in the differential diagnosis.

But that doesn’t mean that elderly patients with depression would require different assessments for cognition in depression. There, I think it is the same: working memory, reaction time, etc, and these deficits need to be measured if we are going to make an impact.