Massachusetts General Hospital, Department of Psychiatry, 149 13th Street, Charlestown, MA 02129, USA; Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA; University of Illinois at Chicago, Department of Psychiatry, 1601 West Taylor, Chicago, IL 60612, USA.
University of Illinois at Chicago, Department of Psychiatry, 1601 West Taylor, Chicago, IL 60612, USA.
Schizophr Res. 2020 Jun;220:232-239. doi: 10.1016/j.schres.2020.03.012. Epub 2020 Mar 20.
Both neurocognition and negative symptoms have demonstrated strong links to functional outcomes, such as work functioning, among those with severe mental illness (SMI). Prior models have suggested that reduced neurocognition 1) precedes or predicts greater negative symptoms and 2) indirectly influences functional outcomes via its impact on negative symptoms. The current study sought to also test a divergent model: whether greater negative symptoms predict reduced neurocognition and indirectly influence work functioning through their impact on neurocognition. Both models were tested using cross-sectional and prospective data spanning 20-years in a sample of 277 people with a SMI with psychotic features. Results showed that both models were supported in cross-sectional analyses. However, in prospective models predicting work functioning, only the models examining the indirect influence of negative symptoms on work functioning (7.5 to up to 20-years later) through neurocognition demonstrated significant mediation (i.e., a significant indirect effect); further, higher negative symptoms significantly predicted lower prospective neurocognition, while lower neurocognition did not significantly predict greater prospective negative symptoms. Although cross-sectional data were consistent with prior models, our prospective models offered greater support for a putative causal pathway running from negative symptoms to neurocognition-rather than the reverse-to work functioning. Findings have implications for mechanisms contributing to longitudinal work functioning and suggest that targeting negative symptoms prior to neurocognition could be more beneficial for long-term work outcomes.
神经认知和阴性症状都与严重精神疾病（SMI）患者的功能结果（如工作功能）有很强的关联。先前的模型表明，神经认知能力下降 1）先于或预测更大的阴性症状，2）通过对阴性症状的影响间接影响功能结果。本研究还试图测试一个发散模型：是否更大的阴性症状预测降低神经认知，并通过对神经认知的影响间接影响工作功能。在有精神病特征的 277 名 SMI 患者的样本中，使用横断和前瞻性数据跨越 20 年，对这两种模型进行了测试。结果表明，在横断面分析中，两种模型都得到了支持。然而，在预测工作功能的前瞻性模型中，只有通过神经认知检验阴性症状对工作功能的间接影响（7.5 到最多 20 年后）的模型显示出显著的中介作用（即，显著的间接效应）；此外，较高的阴性症状显著预测较低的前瞻性神经认知，而较低的神经认知则不能显著预测更大的前瞻性阴性症状。尽管横断面数据与先前的模型一致，但我们的前瞻性模型为从阴性症状到神经认知的潜在因果途径提供了更大的支持，而不是相反的因果途径到工作功能。研究结果对导致纵向工作功能的机制有影响，并表明在神经认知之前针对阴性症状进行干预可能对长期工作结果更有益。
