Background: Neurocognitive deficits exist in euthymic patients with bipolar disorder, but relationships between symptoms, psychosocial and neurological factors remain uncertain.
Aims: To measure neurocognitive function in bipolar disorder and explore links to sub-syndromal mood symptoms, soft neurological signs and psychosocial impairment.
Method: Attention, memory and executive function were tested in 37 euthymic patients with bipolar disorder and 37 controls. Psychosocial functioning, soft neurological signs and residual mood symptoms were assessed.
Results: Performances on tests reflecting executive function and verbal memory (but not attention) were significantly poorer in the bipolar disorder group. Sub-syndromal mood symptoms produced small cognitive effects, predominantly on verbal memory. Soft neurological signs, especially frontal signs, were marked; some patients showed marked social disability which correlated strongly with soft neurological signs but weakly with executive dysfunction, which was linked to illness episodes.
Conclusions: Cognitive dysfunction, social dysfunction and soft signs occur in euthymic patients with bipolar disorder and may represent trait deficits.