INGENIO, IRCE, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), CELLEX, Department 2B, Villarroel 170, 08036, Barcelona, Catalonia, Spain.
Centre for Biomedical Investigation in Respiratory Diseases (CIBERES), Health Institute Carlos III, Madrid, Spain.
Curr Allergy Asthma Rep. 2023 Mar;23(3):153-164. doi: 10.1007/s11882-023-01068-z. Epub 2023 Jan 25.
Olfactory dysfunction contributes to the psychopathology of mental illness. In this review, we describe the neurobiology of olfaction, and the most common olfactory alterations in several mental illnesses. We also highlight the role, hitherto underestimated, that the olfactory pathways play in the regulation of higher brain functions and its involvement in the pathophysiology of psychiatric disorders, as well as the effect of inflammation on neurogenesis as a possible mechanism involved in olfactory dysfunction in psychiatric conditions.
The olfactory deficits present in anxiety, depression, schizophrenia or bipolar disorder consist of specific alterations of different components of the sense of smell, mainly the identification of odours, as well as the qualifications of their hedonic valence (pleasant or unpleasant). Epidemiological findings have shown that both environmental factors, such as air pollutants, and inflammatory disease of the upper respiratory tract, can contribute to an increased risk of mental illness, at least in part, due to peripheral inflammatory mechanisms of the olfactory system. In this review, we describe the neurobiology of olfaction, and the most common olfactory function alterations in several psychiatric conditions and its role as a useful symptom for the differential diagnosis. We also highlight the effect of inflammation on neurogenesis as a possible mechanism involved in olfactory dysfunction in these psychiatric conditions.
嗅觉功能障碍是精神疾病发病机制的一个重要组成部分。在这篇综述中，我们描述了嗅觉的神经生物学，以及几种精神疾病中最常见的嗅觉改变。我们还强调了嗅觉通路在调节大脑高级功能方面的作用（迄今为止被低估了），以及其在精神疾病发病机制中的作用，同时也强调了炎症对神经发生的影响，这可能是精神疾病嗅觉功能障碍的一个潜在机制。
焦虑症、抑郁症、精神分裂症或双相情感障碍患者存在的嗅觉缺陷主要表现为嗅觉的不同成分（主要是气味识别）出现特定改变，以及对其愉悦性（愉快或不愉快）的评定改变。流行病学研究表明，环境因素（如空气污染物）和上呼吸道炎症性疾病都可能导致精神疾病的风险增加，至少部分原因是嗅觉系统的外周炎症机制。在这篇综述中，我们描述了嗅觉的神经生物学，以及几种精神疾病中最常见的嗅觉功能改变，以及其作为鉴别诊断的有用症状的作用。我们还强调了炎症对神经发生的影响，这可能是这些精神疾病嗅觉功能障碍的一个潜在机制。
