Several risk factors make older adults more prone to psychosis. The persistent growth in the elderly population makes important the necessity of accurate diagnosis of psychosis, since this population has special features especially regarding to the pharmacotherapy and side effects.

To review the medical literature related to late-life psychosis.

Medline search and ulterior review of the related literature.

Reinhard et al. [1Reinhard M.M. Late-life psychosis: diagnosis and treatment Curr Psychiatry Rep 2015 ;  17 (2) : 1

Cliquez ici pour aller à la section Références] highlight the fact that up to 60% of patients with late onset psychosis have a secondary psychosis, including: metabolic (electrolite abnormalities, vitamines defficiency…); infections (meningitides, encephalitides…); neurological (dementia, epilepsy…); endocrine (hypoglycemia…); and intoxication. Colijn et al. [2Colijn M.A., et al. Psychosis in later life: a review and update Harv Rev Psychiatry 2015 ;  23 (5) : 354-367 [cross-ref]

Cliquez ici pour aller à la section Références] describe the epidemiological and clinical features of the following disorders: schizophrenia (0.3% lifetime prevalence>65years); delusional disorder (0.18% lifetime prevalence); psychotic depression (0.35% lifetime prevalence); schizoaffective disorder (0.32% lifetime prevalence); Alzheimer disease (41.1% prevalence of psychotic symptoms); Parkinson's disease (43% prevalence of psychotic symptoms); Parkinson's disease dementia (89% prevalence of visual hallucinations); Lewy body dementia (up to 78% prevalence of hallucinations) and vascular dementia (variable estimates of psychotic symptoms). Recommendations for treatment include risperidone, olanzapine, quetiapine, aripiprazole, clozapine, donepezil and rivastigmine.

Differential diagnosis is tremendously important in elderly people, as late-life psychosis can be a manifestation of organic disturbances. Mental disorders such as schizophrenia or psychotic depression may have different manifestations in comparison with early onset psychosis.