Integrate Study

• Research type

  Research Study

• Full title

  Does cannabidiol attenuate the acute effects of delta-9-tetrahydrocannabinol intoxication in individuals diagnosed with schizophrenia? A double-blind, randomised, placebo-controlled experimental study.

• IRAS ID

  278595

• Contact name

  Edward Chesney

• Contact email

  edward.chesney@kcl.ac.uk

• Sponsor organisation

  King's College London and South London and Maudsley NHS Foundation Trust

• Duration of Study in the UK

  3 years, 11 months, 31 days

• Research summary

  Psychotic disorders cause distressing symptoms and severely impact quality of life. The development of new treatments for these disorders has been limited by our incomplete understanding of the mental processes which underlie psychotic symptoms.

  Studies in healthy individuals have shown that ∆9-tetrahydrocannabinol (THC) can temporarily cause psychotic symptoms. They have also shown that cannabidiol (CBD) can prevent THC-induced psychotic symptoms without significantly modifying other subjective effects. THC and CBD can therefore be used to explore the mental processes underlying specific psychotic symptoms such as persecutory beliefs, auditory hallucinations, delusions and lack of motivation.

  The study will be carried out at the NIHR-Wellcome Trust Clinical Research Facility at King’s College Hospital by researchers who have experience in testing cannabis in a laboratory setting. It will recruit participants with a diagnosis of schizophrenia who use cannabis recreationally and for whom cannabis use worsens their symptoms.

  Each participant will attend the laboratory on four occasions: an initial visit to check that they are safe to join the study and three days of experiments. Across the three testing days participants will be administered in a randomized order:
  - oral 1000mg CBD and then inhale cannabis containing 10mg THC
  - oral placebo and then inhale cannabis containing 10mg THC
  - oral placebo and then inhale placebo cannabis

  The THC administration will follow a standardised inhalation procedure using a medical-grade vaporiser device. Participants will then complete a series of cognitive and psychological tests while under the influence of the study drugs.

  All participants must already smoke cannabis regularly so that they are not exposed to any additional harm during the study. The researchers will closely monitor those taking part during and after experimental visits to ensure that they are safe and well.

• REC name

  HSC REC A

• REC reference

  20/NI/0074

• Date of REC Opinion

  28 May 2020

• REC opinion

  Favourable Opinion