ABSTRACT
In psychology, psychiatry, and general medicine there are certain beliefs about depression that have become so widely accepted that they have rarely been questioned. One of them is that depression causes cognitive impairment or, at least, that the two are very strongly correlated with each other. Cognitive deficits, typically impaired memory and concentration, are assumed to coincide with the onset of depression and to resolve as the depression remits. Such cognitive deficits are listed as diagnostic criteria for depression in the psychiatric diagnostic manual, DSM-IV (Frances, Pincus, First, & DSM-IV task force, 1994). However, no distinction is made in DSM-IV between subjective cognitive complaints and objective memory deficits, as if the two were equivalent, when they are not. The reader of DSM-IV would be led to assume that a person in a major depressive episode (1) would complain of impaired memory (subjective impairment), (2) would show deficits on memory tests (objective impairment), and (3) would have impairment of memory in day-to-day life. Finally, (4) the more severe the depression, the greater the objective memory deficits we might expect on objective testing. In this chapter, it will be argued that assumptions (1) to (4) above are usually false. To illustrate how certain general principles apply in clinical practice, the case of a depressed woman making a Worker’s Compensation Board (WCB) claim for cognitive impairment and depression after a motor vehicle accident will be presented.
