In 1859, Ludvig Dahl, a Norwegian alienist, wrote a rarely referenced book entitled “Contribution to The Knowledge of Insanity.” In it, he describes a highly innovative psychiatric genetics research project with severable notable features. First, while the vast majority of 19th century psychiatric genetic studies were based on asylum hospital records, Dahl did field work to find cases of mental illness in certain defined areas within Norway, using census data, key-informants, record reviews, and personal interviews especially of suspected affected individuals. Second, for the first time in the history of psychiatric genetics, and perhaps more broadly in medical genetics, Dahl studied and graphed extensive pedigrees covering up to seven generations demonstrating a high density of psychiatric illness. Third, he proposed and conducted the first controlled investigation of familial aggregation of insanity. A 126 member 5-generation pedigree that he studied contained 8 individuals with confirmed insanity compared to 16 cases in the remaining 2,974 individuals in the Parish, a relative risk of nearly 12. Dahl also noted the co-segregation within pedigrees of mental handicap, deaf-mutism, and insanity. He evaluated familial-environmental sources of familial aggregation and noted, among nonpsychotic family members in his pedigrees, personalities that might reflect a “disposition” to insanity.

中文翻译：

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Ludvig Dahl 在他 1859 年的专着中的精神病学遗传学研究：“对挪威精神错乱知识的贡献”

1859 年，挪威外星人路德维格·达尔 (Ludvig Dahl) 写了一本鲜为人知的书，题为《对精神错乱的认识》(Contribution to The Knowledge of Insanity)。在其中，他描述了一个高度创新的精神遗传学研究项目，具有几个显着特点。首先，虽然 19 世纪的绝大多数精神病基因研究都是基于庇护医院的记录，但达尔使用人口普查数据、关键信息人、记录审查和个人访谈，在挪威的某些特定地区进行了实地工作以发现精神疾病病例尤其是疑似受影响的个人。其次，在精神遗传学的历史上，也许更广泛地在医学遗传学的历史上，达尔第一次研究并绘制了涵盖多达七代人的广泛谱系，证明了精神疾病的高密度。第三，他提出并进行了第一次对精神错乱的家庭聚集的对照调查。他研究的一个 126 名成员的 5 代血统中有 8 人被证实患有精神错乱，而教区其余 2,974 人中有 16 人患有精神错乱，相对风险接近 12。达尔还指出，精神障碍、聋哑人的血统中存在共同隔离-缄默和精神错乱。他评估了家庭聚集的家庭环境来源，并指出，在他家谱中的非精神病家庭成员中，可能反映了精神错乱“倾向”的个性。达尔还注意到精神障碍、聋哑症和精神错乱的谱系中的共同隔离。他评估了家庭聚集的家庭环境来源，并指出，在他家谱中的非精神病家庭成员中，可能反映了精神错乱“倾向”的个性。达尔还注意到精神障碍、聋哑症和精神错乱的谱系中的共同隔离。他评估了家庭聚集的家庭环境来源，并指出，在他家谱中的非精神病家庭成员中，可能反映了精神错乱“倾向”的个性。