Science · Psychiatry & evidence
Understanding the clinical question
Psychiatry studies mental health conditions, their causes, their effects on people’s lives and how care can help. This section focuses on psychosis and clinical high risk, the setting for NWPharmaTech’s current public research programme.
Risk is not a diagnosis
Being considered at clinical high risk is not a diagnosis of schizophrenia. Risk, present symptoms, functioning and longer-term outcomes are different things. A useful research summary makes clear which of these a study measures.
An updated meta-analysis estimated that about one in four people identified as CHR-P (pooled estimate, 25%) developed psychosis within three years; most do not. Sources: Salazar de Pablo et al. 2021
Choose a question
- What does clinical high risk of psychosis mean?The clinical-need explainer
- What does current guidance recommend?Current care, with the NICE guidance entries
- What have CBD studies in psychiatry found?Positive, negative and inconclusive results together
- What has NWPharmaTech studied?The Phase 1 study, and the Programme Room
- What would the planned study establish?The proposed Phase 2B design and its limits
In England, psychological therapy is the recommended first step. NICE advises against antipsychotics to prevent psychosis in this group. Sources: NICE CG178
CBD studies in psychiatry: small, mixed and product-specific
Small trials of other CBD preparations have produced mixed results. These are different trials, not proof that one dose always works and another does not. They studied other products and populations, not NWPT-SM32300 in people at clinical high risk. A reason to investigate a treatment is not an established benefit.
| Study | Evidence type | Who or what was studied | Preparation and route | What was found | Limit |
|---|---|---|---|---|---|
| McGuire et al. 2018 | Human trial | 88 adults with schizophrenia already taking antipsychotics | Oral CBD solution, 1,000 mg/day (not NWPT-SM32300) | Positive psychotic symptoms fell more with CBD than placebo (small difference), and clinicians more often rated patients as improved. Generally well tolerated. | Small, short, add-on treatment in established schizophrenia; not people at clinical high risk. |
| Leweke et al. 2012 | Human trial | 42 inpatients with acute schizophrenia | Oral CBD up to 800 mg/day (not NWPT-SM32300) | Symptoms improved similarly with CBD and amisulpride; CBD had fewer movement side effects, less weight gain and a smaller prolactin rise. | Small and short; no placebo group, so the size of any CBD effect alone is uncertain. |
| Boggs et al. 2018 | Human trial | 36 outpatients with chronic schizophrenia | Oral CBD 600 mg/day (not NWPT-SM32300) | No improvement in cognition or symptoms compared with placebo. | Small; lower dose than some other studies; stable chronic patients. |
| Bhattacharyya et al. 2024 | Human trial | 33 people at clinical high risk (16 CBD, 17 placebo) | Oral CBD 600 mg/day for 21 days (not NWPT-SM32300) | After adjusting for starting scores, symptom and distress scores were lower with CBD than placebo; CBD was well tolerated. | Very small, three weeks, short-letter format; not yet confirmed in a larger trial. |
| Bhattacharyya et al. 2018 | Brain imaging | 33 people at clinical high risk (16 CBD, 17 placebo) and 19 healthy volunteers | Single oral CBD 600 mg dose (not NWPT-SM32300) | During a memory task, brain activity with CBD was intermediate between the placebo group and healthy volunteers in several regions. | Single dose; brain-activity measures, not symptoms or outcomes. |
Summaries are taken from the Evidence library entries. McGuire et al. 2018 and Boggs et al. 2018 are supported at abstract level.
Reading a result
A change in a brain scan is not the same as improved daily functioning. A short-term symptom change does not prove prevention of a future illness. A study in healthy volunteers cannot establish treatment benefit in people with a psychiatric condition.
When reading a study, look for:
- Population: who took part?
- Treatment: which product, dose and route?
- Comparison: compared with what?
- Duration: for how long?
- Outcome: which measure changed?
- Uncertainty: how large, and how certain, was the difference?
The Evidence library uses a consistent format to make these easier to compare.
Our programme. NWPT-SM32300 is investigational. General cannabinoid research does not establish that it is effective. The Programme Room explains what has been studied, what is planned and what remains unknown; the NWPT formulation section explains what the formulation is designed to do and what has been measured.