Urban-Kowalczyk M, Śmigielski J, Strzelecki D
Department of Affective and Psychotic Disorders, Medical University of Lodz, Czechosłowacka 8/10, 92-216 Lodz, Poland.
Department of Geriatrics, Healthy Aging Research Centre (HARC), Medical University of Lodz, Lodz, Poland.
Eur Psychiatry. 2017 Mar;41:16-20. doi: 10.1016/j.eurpsy.2016.09.004. Epub 2017 Feb 3.
The relationship between the olfactory system and emotional processing is an area of growing interest in schizophrenia research. Both the orbitofrontal cortex and amygdala are involved in the processing of olfactory information, and olfactory deficits may be also influenced by endogenous opioids and calcitonin gene-related peptide (CGRP), which is probably involved in dopaminergic transmission. However, the relationship between endorphins and dopaminergic transmission has not been fully explored.
Odor identification performance and valence interaction was evaluated among 50 schizophrenic patients and 50 controls. Schizophrenia symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS). All study participants were subjected to the University of Pennsylvania Smell Identification Test (UPSIT), blood β-endorphin (BE) and CGRP measurement.
Insignificantly higher BE concentrations were observed in the patient group, while significantly higher UPSIT scores were seen in controls (mean UPSIT 32.48 vs 26.82). The patients demonstrated significantly more identification errors for pleasant (P=0.000) and neutral (P=0.055) odors than for unpleasant odors. Patients with higher BE concentrations made more identification errors concerning pleasant (R=-0.292; P=0.04) and neutral odors (R=-0.331; P=0.019). Although the concentration of CGRP was significantly higher in the patient sample (P<0.001), no relationship was observed between concentration and UPSIT performance. A strong negative correlation was observed between PANSS N score and UPSIT total score (R=-0.646; P=0.000), between PANSS N score and identification by valence for pleasant and neutral odors (UPSIT n/16: R=-0.450, P=0.001; UPSIT n/15: R=-0.586, P=0.000), and a weak negative correlation between PANSS N score and identification of unpleasant odors (UPSIT n/9: R=-0.325, P=0.021).
Schizophrenic patients present a unique pattern of smell identification characterized by aberrant hedonic ratings for pleasant odors but not unpleasant ones. Individuals with predominant negative symptoms and higher BE concentrations are most able to identify negative odors.
嗅觉系统与情绪加工之间的关系是精神分裂症研究中一个日益受到关注的领域。眶额皮质和杏仁核均参与嗅觉信息的处理，嗅觉缺陷可能也受内源性阿片类物质和降钙素基因相关肽（CGRP）的影响，后者可能参与多巴胺能传递。然而，内啡肽与多巴胺能传递之间的关系尚未得到充分探索。
对50例精神分裂症患者和50名对照者进行气味识别能力及效价交互作用评估。采用阳性和阴性症状量表（PANSS）评估精神分裂症症状。所有研究参与者均接受宾夕法尼亚大学嗅觉识别测试（UPSIT）、血液β-内啡肽（BE）和CGRP测量。
患者组BE浓度略高，但对照组UPSIT得分显著更高（UPSIT平均分32.48对26.82）。患者对愉悦（P = 0.000）和中性（P = 0.055）气味的识别错误显著多于不愉快气味。BE浓度较高的患者对愉悦（R = -0.292；P = 0.04）和中性气味（R = -0.331；P = 0.019）的识别错误更多。虽然患者样本中CGRP浓度显著更高（P < 0.001），但未观察到浓度与UPSIT表现之间的关系。PANSS阴性症状评分与UPSIT总分之间（R = -0.646；P = 0.000）、PANSS阴性症状评分与愉悦和中性气味按效价识别之间（UPSIT n/16：R = -0.450，P = 0.001；UPSIT n/15：R = -0.586，P = 0.000）呈强负相关，PANSS阴性症状评分与不愉快气味识别之间（UPSIT n/9：R = -0.325，P = 0.021）呈弱负相关。
精神分裂症患者呈现出独特的气味识别模式，其特征为对愉悦气味而非不愉快气味的享乐评级异常。以阴性症状为主且BE浓度较高的个体最难以识别负面气味。
