The brains of women and men may be affected in different ways by bipolar disorder.  Specifically, according to one recent study, the effect of the disorder on memory is more severe in men.

Dr. Sophia Frangou, of the section of Neurobiology of Psychosis, at the Institute of Psychiatry, King’s College in London, and her colleagues found that compared to women, men with type I bipolar disorder had more difficulty with performing on exams testing their immediate memory, as well as visual and auditory memory.

Many previous studies have shown the negative effects of bipolar disorder on cognition (thought processes), although the exact cause of this is difficult to pinpoint. It is known, however, that untreated illness can cause cognitive defects, as can certain treatments and/or medications.

To analyze the effect of gender on cognition in patients with bipolar disorder, Frangou and her colleagues enrolled 132 patients in the study.  86 patients had bipolar I disorder (a subtype which is characterized by more extreme mania).  This group included 36 men with bipolar and 50 women with the disorder.  46 healthy controls were included (21 men and 25 women.)  All of the patients with bipolar I disorder were similar in age of onset, number of episodes or hospitalizations, illness duration, and global assessment of functioning (GAF) scores.

All participants in this study were asked to complete a variety of tests to assess their cognitive function, including tasks to measure general intellectual ability, recognition, memory encoding, response inhibition, retrieval, and executive function (abstraction and perseveration).

The effect of bipolar disorder on patients’ daily lives was assessed using the global assessment of functioning (GAF) scale.

Research found that a difference in the test results of the men compared both to the women with bipolar illness and to the control (healthy) individuals.  Cognitive defects were noted particularly in the areas of immediate memory (similar to short-term memory), retrieval, and encoding processes.  (NOTE:  Memory encoding is the ability to store new memories.)

In addition, as regards the men, there was a statistically significant association between a decreased immediate memory function and an overall decreased GAF score, which indicates that the more severely affected men with bipolar I disorder  would have a harder time dealing with their daily function.

Research also found that there were no apparent differences in general intellectual function, perseverance, ability to form concepts, or the ability to appropriately inhibit a response.

“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,” says Frangou.

Dr. Frangou’s results can be found in the journal Psychological Medicine.

Source: Psychological Medicine