Neuropsychological dysfunction, soft neurological signs and social disability in euthymic patients with bipolar disorder

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.