Thursday, February 16, 2017

Exploring the psychosis spectrum in Parkinson's disease

Researchers from the NIHR Dementia Biomedical Research Unit (BRU) have led a major new review of psychosis in Parkinson’s disease, published in the journal Nature Reviews Neurology.

The review examines the latest research in the field, including questions of how psychosis symptoms in people with Parkinson’s disease relate to the subsequent development of dementia, and how psychosis should be treated in people with Parkinson’s.

In 2007, the clinical and research profile of illusions, hallucinations, delusions and related symptoms in Parkinson disease was raised by grouping them as a single entity - Parkinson’s psychosis.

In this new approach, symptoms previously deemed benign and clinically insignificant such as illusions, increased in importance as the first indication of a progression to severe hallucinations, delusions and dementia. This has led to increased research efforts focusing on the mechanisms of psychosis in Parkinson’s disease and on clinical aspects such as how psychosis is experienced by patients and how it should be treated.

The new publication in Nature Reviews Neurology reviews these research efforts and the evolving view of psychosis in Parkinson’s disease.

Recent developments in the field include recognition that psychosis symptoms become more common as Parkinson’s disease develops, newly-identified memory and other brain dysfunctions associated with psychosis, and novel visual symptoms considered part of the psychosis spectrum including “seeing double” when focusing on specific objects or images.

The review also highlights the approval of a new drug for the treatment of psychosis in people with Parkinson’s disease, pimavanserin.  Researchers from the NIHR Maudsley BRU played a leading role in developing pimavanserin, which was approved by the US Food and Drug Administration (FDA) in April 2016. 

The drug offers a promising alternative treatment to existing antipsychotic drugs, many of which are not suitable for people with Parkinson’s disease.  The review points out that, without effective alternatives, antipsychotic drugs are still used in clinical practice and highlights the need for further research in this area, as well as the development of new ways to treat psychosis in Parkinson’s.

Read the full Review here: The psychosis spectrum in Parkinson disease, by Dominic H. ffytche, Byron Creese, Marios Politis, K. Ray Chaudhuri, Daniel Weintraub, Clive Ballard & Dag Aarsland, Nature Reviews Neurology, 13, 81–95 (2017)