OBJECTIVE At first hospitalization, a long duration of untreated psychosis (DUP) predicts illness severity and worse treatment outcomes. The mechanism of this association, however, remains unclear. It has been hypothesized that lengthy untreated psychosis is toxic or that it reflects a more severe form of schizophrenia. Alternatively, the association may be an artifact of lead-time bias. These hypotheses are tested in a longitudinal study of schizophrenia with 2,137 observations spanning from childhood to 20 years after first admission. METHODS Data were from the Suffolk County Mental Health Project. The cohort included 287 individuals with schizophrenia or schizoaffective disorder. DUP was defined as days from first psychotic symptom to first psychiatric hospitalization. Psychosocial function was assessed using the Premorbid Adjustment Scale and the Global Assessment of Functioning Scale. Psychosocial function trajectories were estimated using multilevel spline regression models adjusted for gender, occupational status, race, and antipsychotic medication. RESULTS Both long- and short-DUP patients experienced similar declines in psychosocial function, but declines occurred at different times relative to first admission. Long-DUP patients experienced most of these declines prior to first admission, while short-DUP patients experienced declines after first admission. When psychosocial function was analyzed relative to psychosis onset, DUP did not predict illness course. CONCLUSIONS The association between DUP and psychosocial function may be an artifact of early detection, creating the illusion that early intervention is associated with improved outcomes. In other words, DUP may be better understood as an indicator of illness stage than a predictor of course.

中文翻译：

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前置时间偏误混淆了未治疗的精神病持续时间与精神分裂症病程之间的关联。

目的首次住院时，长期未治疗的精神病（DUP）会预测疾病的严重程度和较差的治疗结果。但是，这种关联的机制仍不清楚。据推测，长期未治疗的精神病是有毒的，或者反映出一种更严重的精神分裂症。替代地，该关联可以是提前期偏差的伪像。这些假设在精神分裂症的纵向研究中得到了检验，从儿童期到首次入院后的20年间共进行了2137项观察。方法数据来自萨福克县精神卫生项目。该队列包括287例精神分裂症或精神分裂症患者。DUP被定义为从第一次精神病症状到第一次精神病住院的天数。使用病前调整量表和整体功能量表评估心理社会功能。使用针对性别，职业状况，种族和抗精神病药物调整后的多级样条回归模型估算社会心理功能的轨迹。结果长期和短期DUP患者的社会心理功能均有相似的下降，但相对于首次入院，下降的时间不同。长DUP患者在首次入院前经历了大部分下降，而短DUP患者在首次入院后经历了下降。当分析与精神病发作有关的社会心理功能时，DUP不能预测病程。结论DUP与社会心理功能之间的关联可能是早期发现的产物，产生一种幻想，即早期干预与改善预后有关。换句话说，DUP可能比预测因子更好地理解为疾病阶段的指标。