A study of verbal memory in a sample of euthymic patients with bipolar disorder

Recent studies have confirmed the presence of cognitive impairment in euthymic patients with Bipolar Disorder (BD). A significant relationship between memory difficulties and poor psychosocial adjustment has also been found in these subjects. While some studies suggest that these memory deficits may be secondary to executive functioning instead of being directly related to a primary impairment of the memory systems, others suggest that these memory deficits may be secondary to clinical symptoms. Some authors reject the existence of any relationship between clinical state and neurocognitive impairments and suggest that this relationship may be mediated by other factors. The goal of this research was to replicate the findings of verbal memory impairment in euthymic patients with Bipolar Disorder and relate these impairments with neocortex structures.

We carried out a cross-sectional study. The sample was made up of 44 BDI and 9 BDII euthymic patients and 32 healthy subjects, aged 18-65 years. Both groups were evaluated with the California Verbal Learning Test.

Both bipolar patients performed worse than healthy control subjects in most memory measures and showed difficulties in components of memory that are associated with both frontal (semantic organization) and temporal lobe function (recall and recognition).

We have hypothesized that verbal memory could be a trait marker of bipolar disorder.