Cognitive impairment in remission in bipolar affective disorder

Background. Although the traditional view of bipolar affective disorder is that the majority of patients have full remission between episodes, recent evidence suggests that residual cognitive deficits are present. The aim of this study was to determine whether memory and executive deficits were pres ent in a well-defined clinically remitted group of patients. Methods. This was a case-control study of bipolar patients in remission (N = 18). Subjects had to fulfil stringent clinical criteria for inclusion int o the study and had to have been in remission for at least 4 months. Subjec ts also had no history of substance dependence. The cognitive battery exami ned memory and executive function. Results. Patients in excellent clinical remission and who reported good soc ial adaptation showed impairment on tests of visuospatial recognition memor y. Accuracy on four tests of executive function was not impaired in patient s in remission compared with controls, although response latency on these e xecutive tests was still impaired. Conclusions. As our group and others have shown, patients with mania and un ipolar depression show generalized impairment on tests of memory and execut ive function. In comparison, this study has demonstrated that patients in r emission show a relatively specific impairment in memory with recovery of a ccuracy measures on executive function task. The increased response latency on the executive tasks suggests a possible small residual impairment. Thes e findings suggest that in neuroanatomical terms, more posterior cortical f unction (temporal lobe) has not improved but there is at least some recover y of frontal lobe function in remission.