New challenges in the field of psychiatric disorders have emerged from the increase in life expectancy and the consequent aging of the world’s population during recent decades. Although there is a general pattern of decreasing rates of psychiatric conditions—such as psychotic, bipolar, obsessive compulsive, and major depressive disorders—with increasing age, the absolute number of individuals affected by such conditions is expected to rise rapidly as the population becomes older. Similar to what is observed at earlier ages, psychiatric disorders in late life exert a strong negative impact on functional outcomes, generating suffering and high economic costs to both affected individuals and their caregivers. For these reasons, late-life psychiatric disorders represent a public health problem requiring a special focus and specific treatment approaches. In turn, the population of individuals affected by these conditions constitutes a field that offers a unique opportunity to explore the underlying mechanisms involved in the development and maintenance of major psychiatric disorders.

Notwithstanding the lack of clear consensus regarding the definition of “late-life psychiatric disorder”, the age of 50 has recently been proposed as a demarcation criterion for research, since at that age there is an increase in the prevalence of medical comorbidities. Of note, heterogeneity is remarkably high among individuals affected by the same given late-life psychiatric disorder, with “age at illness onset” significantly accounting for such variability. While most patients undergo the onset of psychiatric disorders in adolescence or early adulthood, a sizeable minority experience new-onset psychiatric conditions during middle or old age. Early and late-onset forms of a given psychiatric disorder may be distinguishable in terms of pathogenesis, clinical and neuropsychological features, course of illness, and care needs.

This special issue aims to provide neuroscientific insight into less prevalent forms of psychiatric disorders with onset in late life. The division between psychiatric and neurologic disorders is considered an artifact of a long-held dualistic conception in the field; however, in order not to be so broad as to lack focus, the special issue particularly welcomes the submission of articles addressing recent neuroscientific advances in disorders typically considered as “psychiatric” when first becoming evident in late years.

Potential topics include but are not limited to the following:

• Clinical presentation of specific psychiatric disorders emerging in late life as compared with that of early-onset late-life psychiatric disorders
• Neuropsychological features of any specific new-onset psychiatric disorder in late life
• Neuroimaging findings for any specific new-onset psychiatric disorder in late life
• Therapeutic approaches to the treatment of any psychiatric disorder emerging in late life
• Psychiatric conditions underlying the phenocopy syndrome of behavioural-variant major frontotemporal neurocognitive disorder