ABSTRACT
Objective To examine the heritability of neurocognitive functions in bipolar I disorder(BD-I)families and BD-associated cognitive endophenotypes. Methods Seventy-nine nuclear families consisting of euthymic BD-I probands and their healthy parents were recruited. Cognitive functions including attention, working memory, processing speed and executive function were evaluated by 7 classic neurocognitive tests, and the heritability of neuroconitive functions in these families was estimated using parent-offspring regression indexes of quantitative traits.Furthermore,the heritable cognitions were compared between 79 BD probands and 140 normal controls. Results After adjusted by age and education,mistake numbers of Trail Making Test A(TMT-A),total score and completed mission numbers of Tower of Hanoi (TOH) were significantly heritable (P<0.05). The comparison of these heritable cognitions between patients and normal controls showed that TOH total score and TOH completed mission numbers were significantly impaired in the patient group (P<0.05). Conclusion Processing speed and executive function are probably heritable in BD nuclear families. Executive function impairments may be disease-related which could be candidate endophenotypes for bipolar disorder.