Steiger Howard, Richardson Jodie, Schmitz Norbert, Joober Ridha, Israel Mimi, Bruce Kenneth R, Gauvin Lise, Dandurand Cathy, Anestin Annelie
Eating Disorders Program, Douglas University Institute in Mental Health, Quebec, Canada.
J Psychiatr Res. 2009 Sep;43(13):1086-94. doi: 10.1016/j.jpsychires.2009.03.009. Epub 2009 Apr 21.
Efforts to classify eating-disordered individuals based on concurrent personality traits have consistently converged on a typology encompassing "over-regulated", "dysregulated", and "low psychopathology" subgroups. In various populations, evidence has associated personality variations of an "over-regulated/dysregulated" type with differences on serotonin-system indices, and specifically, with different loadings of serotonin transporter promoter regulatory region polymorphism (5HTTLPR) genotypes and alleles. We explored the extent to which an empirical, trait-defined typology of eating-disordered individuals coincided systematically with variations in 5HTTLPR, assayed using biallelic and triallelic models.
We tested 185 women with a DSM-IV eating disorder (108 with Bulimia Nervosa, 17 Anorexia Nervosa, and 60 an Eating Disorder Not Otherwise Specified) and 93 with no eating disorder on measures reflecting psychopathological traits and 5HTTLPR (biallelic and triallelic) genotypes and alleles.
The highest-function, triallelic (L(A)/L(A)) genotype occurred significantly more frequently among eating-disordered individuals than among controls. However, a more fine-grained analysis suggested that this association was attributable to the fact that, among eating-disordered participants, those displaying an "Inhibited/Compulsive" profile (derived using latent class analysis) were more likely than those of a "Dissocial/Impulsive" or a "Low Psychopathology" group to carry the triallelic 5HTTLPR gain-of-function L(A) allele and to be L(A)/L(A) homozygotes.
This study's empirically derived classes coincide with interpretable differences on genetic indices-associating an "Inhibited/Compulsive" group with 5HTTLPR gain-of-function genotypes (and alleles) that have elsewhere been linked to trait compulsivity. The findings, furthermore, suggest that 5HTTLPR, by influencing personality-trait manifestations may, in turn, influence eating-disorder risk and symptom expression.
基于并发的人格特质对饮食失调个体进行分类的研究一直聚焦于一种包含“过度调节型”“调节失调型”和“低精神病理学型”亚组的类型学。在不同人群中，有证据表明“过度调节/调节失调型”的人格差异与血清素系统指标的差异相关，具体而言，与血清素转运体启动子调控区多态性（5HTTLPR）基因型和等位基因的不同负荷有关。我们探讨了基于实证、由特质定义的饮食失调个体类型学与使用双等位基因和三等位基因模型检测的5HTTLPR变异在多大程度上系统地相符。
我们对185名患有《精神疾病诊断与统计手册》第四版（DSM-IV）饮食失调的女性（108名神经性贪食症患者、17名神经性厌食症患者和60名未另行规定的饮食失调患者）以及93名无饮食失调的女性进行了测试，检测反映精神病理学特质以及5HTTLPR（双等位基因和三等位基因）基因型和等位基因的指标。
功能最高的三等位基因（L(A)/L(A)）基因型在饮食失调个体中出现的频率显著高于对照组。然而，更细致的分析表明，这种关联归因于以下事实：在饮食失调参与者中，表现出“抑制/强迫”特征（通过潜在类别分析得出）的个体比“反社会/冲动”或“低精神病理学”组的个体更有可能携带三等位基因5HTTLPR功能获得性L(A)等位基因并成为L(A)/L(A)纯合子。
本研究通过实证得出的类别与基因指标上可解释的差异相符，即将“抑制/强迫”组与5HTTLPR功能获得性基因型（和等位基因）联系起来，而这些基因型（和等位基因）在其他地方已与特质强迫性相关联。此外，研究结果表明，5HTTLPR通过影响人格特质表现，可能反过来影响饮食失调风险和症状表达。
