Advances in the study of drugs to combat cognitive impairment in schizophrenia

Schizophrenia is a serious, chronic mental disorder involving a series of symptoms. It is one of the leading causes of disability worldwide. Various symptoms of this disorder, such as delusions and hallucinations, have been shown to be very adequately treated by means of antipsychotics, and its symptomatology can be improved. Yet patients experience many difficulties on a social and functional level, in other words, “they have severe problems in carrying out everyday life activities ranging from personal hygiene or managing their finances to maintaining a stable social network, having a partner or holding down a job. And there is no treatment for this”, explained Arantzazu Zabala, a Doctor in Psychology specialising in neuropsychology.

Since the year 2000, explained Zabala, one of the authors of the work, “it has emerged that it is the cognitive impairments that correlate most with functional deficits, and since then, to combat these deficits, the scientific community has been developing a broad range of interventions, including cognitive enhancers. These are drugs which when added to the routine, antipsychotic treatment, could reverse or, to a certain extent, reduce the cognitive impairments displayed by patients”.

Nine clinical trials from across the world were analysed in a study conducted by researchers from the UPV/EHU, the University of La Rioja, the BioCruces Health Research Institute and Cibersam (Centre for Biomedical Research into Mental Health). The trials involved patients with schizophrenia and used three acetylcholinesterase inhibitors (deonepezil, galantamine and rivastignine)that are very effective in improving the cognitive impairments of patients with Alzheimer’s. As the researcher explained, “right now there is insufficient evidence to be able to recommend acetylcholinesterase inhibitors as a cognitive enhancer for patients with schizophrenia”. In fact, numerous limitations in the nine trials studied have emerged in this meta-analysis, and various improvements that need to be applied to studies of this type have been proposed.

Doctor Zabala is nevertheless optimistic: “Much work remains to be done, but it’s heading in the right direction.” The researcher insists that the trials analysed “are original pieces of work, are among the first ones, but right now the therapeutic targets have expanded greatly. Our work draws attention to the need for studies that will offer sufficient methodological quality to be able to guarantee the effectiveness of the compounds”. In this respect, the research conducted at the UPV/EHU proposes a series of improvements in studies of this type, which the scientific community should bear in mind “so that in addition to demonstrating the effectiveness of a drug on the patient’s functionality, aspects such as the safety and tolerance of it are also studied,” concluded Zabala.

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The research was carried out by lecturers and researchers in the field of Psychiatry in the Department of Neurosciences and the Department of Preventive Medicine and Public Health of the Faculty of Medicine and Nursing of the UPV/EHU, in collaboration with researchers from the International University of La Rioja. Various researchers who are authors of this work participate in CIBERSAM (Centre for Biomedical Research into Mental Health) and belong to the BioCruces Health Research Institute.

Borja Santos, Eduardo González-Fraile, Arantzazu Zabala, Virginia Guillén, José Ramón Rueda, Javier Ballesteros

Cognitive improvement of acetylcholinesterase inhibitors in schizophrenia

Journal of Psychopharmacology (2018)

DOI: 10.1177/0269881118805496