Schürhoff Franck, Szöke Andrei, Méary Alexandre, Bellivier Frank, Rouillon Frédéric, Pauls David, Leboyer Marion
Service de Psychiatrie Adulte, Hôpital albert Chenevier et Henri Mondor, France.
Am J Psychiatry. 2003 Jul;160(7):1313-9. doi: 10.1176/appi.ajp.160.7.1313.
Clinical, familial, and, more recently, genetic linkage studies suggest that overlapping genetic susceptibility might contribute to both schizophrenia and bipolar disorder. To identify a potential psychotic dimension common to families of both bipolar and schizophrenia probands, the authors tested if delusional proneness was observed among first-degree relatives of bipolar and schizophrenia probands.
The authors included 32 schizophrenia probands and 61 bipolar probands and their respective first-degree relatives (N=63 and N=59). They were all interviewed with the Diagnostic Interview for Genetic Studies, and delusional proneness was assessed with a self-report questionnaire, the Peters et al. Delusions Inventory. Schizophrenia and bipolar probands were subdivided into subgroups according to the intensity of delusional symptoms assessed by Peters et al. Delusions Inventory scores, and the authors compared delusional proneness in their respective first-degree relatives.
Familial aggregation of delusional proneness was demonstrated, since Peters et al. Delusions Inventory scores were higher among nonschizophrenic first-degree relatives of schizophrenia probands with productive symptoms and among first-degree relatives of bipolar probands with psychotic features during their affective episodes. The authors also found an intrafamilial correlation of delusional proneness scores in nonaffected siblings of schizophrenia and bipolar probands.
Delusional proneness appears to be an inherited predisposition common to both schizophrenia and bipolar disorder. In the future, this dimension might be valuable when used as a quantitative phenotype in linkage and association studies.
临床研究、家族研究以及最近的基因连锁研究表明，重叠的遗传易感性可能在精神分裂症和双相情感障碍中都起作用。为了确定双相情感障碍和精神分裂症先证者家族中共同存在的潜在精神病维度，作者测试了双相情感障碍和精神分裂症先证者的一级亲属中是否存在妄想倾向。
作者纳入了32名精神分裂症先证者、61名双相情感障碍先证者以及他们各自的一级亲属（分别为63名和59名）。他们都接受了基因研究诊断访谈，并使用一份自我报告问卷——彼得斯等人的妄想量表来评估妄想倾向。根据彼得斯等人的妄想量表得分所评估的妄想症状强度，将精神分裂症和双相情感障碍先证者分为亚组，作者比较了他们各自一级亲属中的妄想倾向。
妄想倾向的家族聚集性得到了证实，因为在有明显症状的精神分裂症先证者的非精神分裂症一级亲属中以及在情感发作时有精神病特征的双相情感障碍先证者的一级亲属中，彼得斯等人的妄想量表得分更高。作者还发现，精神分裂症和双相情感障碍先证者未患病的兄弟姐妹中，妄想倾向得分存在家族内相关性。
妄想倾向似乎是精神分裂症和双相情感障碍共有的一种遗传易感性。未来，这一维度在连锁和关联研究中用作定量表型时可能具有价值。
