To further improve clinical activities in psychiatry by early diagnosis and early intervention with novel mechanism-guided treatments, there is a great need for biomarkers that reflect 'trait' and 'state' in major mental disorders. Stable trait biomarkers would allow early diagnosis, prognosis, and hopefully early intervention in these disorders, while dynamic state markers that reflect symptomatic changes would help to develop treatments that target these molecular mechanisms. However, in the search for such biomarkers, and eventually translating them to the clinic and industry, challenges currently exist at multiple levels, from basic scientific understanding, patient sample collection, and sample and data management, to bridging the gap between basic and clinical research and industry. To address these challenges, we propose an infrastructure that emphasizes: (i) a research and educational framework to facilitate translation between basic neuroscience, clinical research, and industry; (ii) patient recruitment and collection of disease-relevant samples to study trait and state biomarkers; and (iii) a comprehensive database to integrate patient and sample information with biological and clinical data. We believe that such an approach would bolster: research into the biological mechanisms of psychiatric disorders; and collaboration among the laboratory, clinic, and industry to translate these findings into successful treatments.

Biopsy is an essential procedure of clinical medicine in which we obtain tissues and cells that are supposed to directly reflect pathological changes of each disease. Biopsy from the brain is difficult at both practical and ethical levels. Nasal biopsy that captures tissues with olfactory neurons has been considered as an alternative method of obtaining neurons from living patients with brain disorders. However, insufficient characterization of biopsied cells/tissues has hampered a wider use of nasal tissues as surrogate resources for the brain. By conducting single cell and bulk RNA-sequence analysis of olfactory neuronal cells (ONCs) enriched from nasal biopsied tissues and using multiple pubic datasets in comparison, we now report precise characterization of ONCs at the molecular levels. These cells are easily and reproducibly prepared and have two major strengths. They are homogeneous and neuronal, resembling excitatory neurons in the dorsolateral prefrontal cortex and anterior cingulate cortex in molecular signatures.