Until 2020, only Belgium, Luxembourg, Switzerland, and the Netherlands admitted, under differentiated legal coverage, requests for euthanasia and / or assisted suicide in patients with non-terminal illnesses, and for reasons of intractable and unbearable suffering. Since March 2021 this is also possible in Spain. The objective of this work is to review the existing studies and characteristics of the practice of euthanasia and assisted suicide (ESA) in people with mental disorders (TM) and / or dementia (D) and see if the legal requirements essential in ESA applications in these patients are to be met. The hypothesis is that compliance with these requirements is especially difficult in patients with TM-D, either because of the characteristics of the disease itself, or because of the recognized legal security failures. Likewise, there may be sources of fraud not actually prosecuted by the State, either due to the complicity of society and / or due to the necessary cooperation of Medicine. As a result of this review, we raise criticaethical-deontological considerations about the approval of ESA for patients with TM-D, and its errors and consequences, to the reflection of the readers. We propose as an alternative to ESA the so-called ″palliative psychiatry″, which aims at improving the quality of life of patients and their families by facing the problems associated with severe persistent mental illness -potentially fatal- through the prevention and relief of suffering.