Cognition in bipolar disorder
background Bipolar patients suffer from cognitive dysfunctions, mainly in attention, verbal memory and executive functioning. These cognitive dysfunctions are suspected to be related to social functioning. However, due to relatively few comparative studies and many methodological pitfalls, the exact extent and kind of cognitive dysfunctions in bipolar disorder is unknown. Also, the relationship between cognitive dysfunctions and social functioning has not been sufficiently studied.
aim Assessment of the extent and kind of cognitive dysfunctions in bipolar patients compared to healthy controls. Other objectives are to study the relationship between cognitive functioning and illness characteristics, as well as psychosocial outcome parameters.
method 150 bipolar patients (umc Groningen) and 75 controls (local newspaper Groningen) will be included. Data contain the cognitive function (both objective tests and subjective complaints), evaluation of illness- and patient characteristics and outcome measurements. Cognitive dysfunction in one of the cognitive tasks is defined as a score of 2 standard deviations below the average of the healthy control group in the same task..
results We will present the latest data at the Congress in April 2008 in Amsterdam. Preliminary results from 64 bipolar patients and 41 healthy controls revealed that almost 55% of bipolar patients were cognitive impaired, with lower scores on different measurements of attention, memory and executive functioning. Cognitive disturbed bipolar patients reported more previous manic episodes and surprisingly less depressive symptoms. No relationship was found between objective cognitive functioning and subjective complaints or psychosocial outcome measurements. Subjective cognitive functioning was related to depressive symptoms and to some outcome parameters of social functioning.
conclusion Preliminary results do confirm cognitive dysfunctions in around 50% of bipolar patients, mainly in attention, memory and executive functioning. Cognitive dysfunctions seem to be related to the number of manic episodes. Objective cognitive functioning may not be related to psychosocial outcome, while subjective complaints about cognitive functioning are related to psychosocial outcome.