Gender differences in bipolar I disorder are associated with memory function and may contribute to poor functional outcome particularly in men, UK researchers report.

They found gender by diagnosis interactions in patients with bipolar I disorder were present in immediate memory, both auditory and visual, but not in general intellectual ability, concept formation, and perseveration or response inhibition.

The researchers also note that it is unlikely that their findings “relate to potential differences in illness severity between men and women with bipolar I disorder,” because both patient groups were comparable in terms of age of onset, duration of illness, number of episodes or hospitalizations and global assessment of functioning (GAF) scores.

They evaluated the performances of 86 remitted patients with bipolar I disorder (36 men and 50 women) and 46 mentally healthy individuals (21 men and 25 women) on a series of cognitive tasks.

On the Weschler Memory Scale-III (WMS-III), patients with bipolar I disorder performed significantly worse than mentally healthy controls in immediate visual and auditory memory and auditory delayed memory, but not in visual delayed memory or auditory recognition delayed memory.

When the effects of gender were assessed, women with bipolar I disorder did not perform significantly worse than control women on any of these WMS-III variables, whereas men with bipolar I disorder performed significantly worse than men without the disorder in auditory (average score 96.5 vs 113.2) and visual immediate (92.2 vs 110.7) memory, and marginally worse in auditory delayed memory (92.3 vs 103.3).

Compared with women with bipolar I disorder, men with the condition performed worse in immediate memory (102.4 vs 93.4, respectively) and auditory delayed memory (105.8 vs 92.3), but not significantly so. Immediate memory was significantly correlated with male patients’ overall level of functioning, however, underscoring the importance of memory function in the outcome of bipolar disorder.

Further analysis of the abnormalities in immediate memory test performance, which could reflect either encoding or retrieval, showed that it was retrieval deficits that were greater in men than women with bipolar I disorder.

“This is further supported by the finding of gender differences in delayed auditory memory in bipolar disorder,” say Sophia Frangou, from King’s College London, and colleagues in the journal Psychological Medicine.

They conclude: “Our results support the notion that gender may modulate the degree of immediate memory dysfunction in bipolar disorder and its impact on overall level of function.

MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

Free abstract

• ">
• Mood Dysfunction Improved In Gene Knockout Mice
• Eurand Announces FDA Approval Of EUR-1048 (Lamictal(R) ODTTM), Co-Developed With GlaxoSmithKline
• New Certified Reference Materials Offer Greater Certainty In Monitoring 3 Therapeutic Medications