OBJECTIVE: Garcinia mangostana Linn., commonly known as
mangosteen , is a tropical
fruit with a thick pericarp rind containing bioactive compounds that may be beneficial as an adjunctive
treatment for
schizophrenia . The
biological underpinnings of
schizophrenia are believed to involve altered
neurotransmission ,
inflammation ,
redox systems,
mitochondrial dysfunction , and
neurogenesis .
Mangosteen pericarp contains
xanthones which may target these
biological pathways and improve symptoms; this is supported by preclinical evidence. Here we outline the protocol for a double-blind randomized placebo-controlled trial evaluating the
efficacy of adjunctive
mangosteen pericarp (1,000 mg/day), compared to placebo, in the
treatment of
schizophrenia .
METHODS: We aim to recruit 150 participants across two sites (Geelong and Brisbane). Participants diagnosed with
schizophrenia or
schizoaffective disorder will be randomized to receive 24 weeks of either adjunctive 1,000 mg/day of
mangosteen pericarp or matched placebo, in addition to their usual
treatment . The primary
outcome measure is mean change in the Positive and Negative Symptom Scale (total score) over the 24 weeks.
Secondary outcomes include positive and negative
symptoms, general psychopathology , clinical global severity and improvement,
depressive symptoms ,
life satisfaction , functioning, participants reported overall improvement, substance use,
cognition ,
safety and
biological data. A 4-week post
treatment interview at week 28
will explore post-discontinuations effects.
RESULTS: Ethical and
governance approvals were gained and the trial commenced.
CONCLUSION: A positive finding in this study has the potential to provide a new adjunctive
treatment option for people with
schizophrenia and
schizoaffective disorder . It may also
lead to a greater
understanding of the pathophysiology of the disorder.