In the field of psychiatry, two of the most challenging diseases to differentiate are autoimmune encephalitis and frontotemporal dementia. Autoimmune encephalitis can be difficult to distinguish from schizophrenia or related conditions during the first-episode psychosis. Behavioral variant frontotemporal dementia can be misdiagnosed as various psychiatric disorders as well as other neurological disorders. The key to proper differentiation is a thorough understanding of the core psychiatric symptoms of schizophrenia and behavioral variant frontotemporal dementia. Pointing out the differences from those pathological conditions often leads to clues for making the correct diagnosis.

As knowledge of the relationship between the pathophysiology and clinical manifestations of neurological disorders increases, the overlap of the fields between neurology and psychiatry continues to grow. However, our clinical practice is still deeply divided along specialty lines, and we have not been able to adequately address the interface between the two specialties. This paper focuses on behavioral symptoms observed in Lewy body disease and motor symptoms observed in endogenous psychosis representative of the areas where collaboration between neurology and psychiatry is needed.

Japan possesses the world’s most rapidly aging population. Consequently, a rise in the number of dementia patients and a decline in the working-age population are unavoidable. It is imperative for multi-disciplinary teams to provide support to individuals with dementia and their caregivers within the community, ensuring these individuals with dementia lead lives to the fullest extent possible. Dementia disease medical centers are located in each prefecture and in ordinance-designated cities as bases for dementia care. In addition to Alzheimer’s dementia which accounts for 70% of all dementias, there are many cases of dementia due to physical diseases such as Parkinson’s disease. Therefore, it is important to confirm the diagnosis at an early stage through cooperation with neurologists and psychiatrists. In addition, it is necessary to establish a local support system with the cooperation of healthcare providers and community care professionals. In this article, dementia care and support systems, including dementia disease medical centers are described. Also, we introduce our hospital’s initiatives such as online medical consultations and iSupport, a program for people who care for people with dementia.

Based on the hub-and-spoke model of medical collaboration between psychiatric hospitals in Osaka Prefecture, centered on the Kansai Medical University General Medical Center, the “Center for Mental Disorders and Physical Complications” was established to provide psychiatric and physical complications care to the entire Osaka area. It is necessary to differentiate among disorders that present with psychiatric symptoms, bearing in mind that there are various neurological disorders, including organic mental disorders. Among them, “autoimmune encephalitis”, “symptomatic epilepsy, psychogenic non-epileptic seizures”, and “Creutzfeldt-Jakob disease”, which are difficult to diagnose and important diseases, were explained. Each of these diseases has its own characteristics and may be difficult to diagnose when treated only by psychiatry. In the future, there will be an increasing need for general hospitals that can specialize in treating physical diseases in addition to treating psychiatric disorders.

Nagasaki University Hospital serves as the central facility for psychiatry and neurology in Nagasaki Prefecture. The hospital deploys physicians to numerous medical establishments within the prefecture and collaborates closely with them. Inter-departmental relationships within the hospital are strong. Collaboration is enhanced not only through clinical case consultations but also by jointly conducting study sessions. Goto Chuo Hospital is a general hospital on Fukue Island. Because there are no neurologists on the island, Nagasaki University Hospital dispatches neurologists twice a month to the island, but this is sometimes canceled due to bad weather. Therefore, we are attempting to advance telemedicine by utilizing a humanoid robot as a foundational step towards shaping the future of telemedical practices. By accessing the robot installed at Goto Chuo Hospital, professional psychiatrists working at Nagasaki University Hospital will be able to communicate with patients in Goto Chuo Hospital and give advice to local doctors in the hospital.

Hyogo Medical University Hospital has a medical center which specializes in dementia treatment. Generally, many facilities often have either psychiatrists or neurologists, but our hospital has two psychiatrists and three neurologists. We can execute specialized tasks by leveraging the expertise of each department. We reported one case in which a psychiatrist diagnosed mild cognitive impairment, but the neuroimaging results indicated the presence of corticobasal syndrome. Since suspicious findings were collected, further scrutiny was carried out at the medical center’s Department of Neurology. Consequently, we undertook this case, which continues to be regularly monitored by both a psychiatrist and a neurologist from their respective departments.

In a memory clinic, psychiatrists are confronted with patients exhibiting a wide array of symptoms. In addition to typical cases of dementia, psychiatrists must also manage atypical cases, necessitating consideration of various neurodegenerative disorders. Collaboration with neurologists should be needed in this regard. Conversely, psychiatric symptoms and disorders can also impact neurological disorders. Thus, psychiatrists have a responsibility to provide suggestions to neurologists regarding psychiatric disorders, particularly neurodevelopmental disorders. The integration of these perspectives can enable more effective management of patients with dementia.

Recently, advances have emerged in our understanding of psychiatric disorders at the level of the so-called connectome, a map of the neural circuitry of the entire brain. Neurological diseases are also on the same map. Here, we have described what was known about the mechanism of psychiatric symptoms in multiple sclerosis, NPSLE, and anti-NMDAR antibody encephalitis (autoimmune encephalitis) from the viewpoint of the brain’s immune system. In the future, the mechanism of psychiatric symptom expression in other neurological disorders will be elucidated as well. We have entered an era in which both departments are joining forces to provide medical care, research, and education to translate the recent remarkable developments in neuroscience into clinical practice.

Background: Online psychotherapy is extensively practiced given the shortage of doctors and in consideration of the COVID-19 pandemic. This study aimed to evaluate the applicability of video analyses using an automated facial coding software to assess the empathetic facial expressions of health professionals during online psychotherapy. Methods: University lecturers specializing in clinical psychology or medicine (n = 4) and university students (n = 4) participated as health professionals in the demonstrations of online psychotherapy. A simulated patient appeared to be suffering from insomnia and fatigue caused by care burden in the first medical examination. Psychotherapy videos were recorded by an online conference system and analyzed using an automated facial coding software called “Face Reader.” Results: The “Face Reader” could detect all facial action units of the health professionals except for their line of sight. The facial expression scores for neutral, anger, and disgust were significantly higher among university lecturers than university students. Conclusions: These results show that video analyses using an automated facial coding software can detect the facial expressions of health professionals. The concentrated expression of what appears to be anger or disgust is probably the typical facial expression among health professionals during online psychotherapy.

Traumatic brain injury (TBI) results in prognostic symptoms, including brain dysfunction. However, only a few cases manifest psychotic symptoms several years after a single severe TBI (ssTBI). We report a case suffering from hallucinations six years after TBI with brain dysfunction, and two years after the death of his son. A 45-year-old man developed a psychotic disorder following TBI. At the age of 39, he was struck by a car, resulting in bilateral frontal lobe cerebral contusions and a subsequent coma. He regained consciousness and was discharged after 7 months of hospitalization. He was rehabilitated in his home and was able to return to work. However, a psychological test revealed that he had residual higher brain dysfunction. At 42, his second-oldest son died young of heart disease. At the age of 45, he experienced auditory hallucinations, hearing phrases like “Dad, Mom” in a boy’s voice distinct from that of his deceased son. Initially, he recognized these as hallucinations, but over time, he became increasingly agitated and lost insight into his condition. He made his first visit to our department and received intensive examination and treatment in hospital. Cerebral blood flow scintigraphy showed decreased blood flow in the frontal lobe, and electroencephalogram (EEG) showed θ waves in the frontal area, consistent with a psychotic disorder following traumatic brain injury (PDFTBI). His psychotic symptoms improved with pharmacotherapy and he became aware of the disease. Although the clinical course and laboratory findings were consistent with a psychotic disorder following TBI, it is important to differentiate this case from schizophrenia and auditory hallucinations in a dissociative disorder.