Key inclusion criteria
1. Aged between 15 and 45 years (inclusive).
2. Fulfil the DSM-IV criteria practice for broadly defined early psychosis, based on the Diagnostic Interview for Psychosis. This includes diagnoses such as schizophrenia, schizophreniform psychosis, delusional disorder, bipolar disorder, psychosis not otherwise specified.
3. Have had the onset of a psychotic disorder within the last two years
4. Have received antipsychotic medications for a period of at least one continuous month within the above two year period.
5. Have a Positive and Negative Syndrome Scale (PANSS) total score of at least 55.
6. Agree to participate, has capacity to consent and able to follow the study instructions and procedures.
7. If under 18 years of age, a parent or legal guardian consents to the young person’s participation.
Both males and females
Key exclusion criteria
1. Known allergies to sodium benzoate (E211) or any part of the formulation of the investigational product.
2. Suspected allergies or known adverse reactions to food preservatives in general.
3. Comorbid physical illnesses that would impair the participants’ ability to complete the trial.
4. People who are unable to understand or communicate in English.
5. For female participant, those currently pregnant, or planning to become pregnant or lactating during the study period
6. Inability to follow the study instructions and procedures.