Hospital del Mar Research Institute Hospital del Mar Research Institute

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ENDED study

Molecular and neuronal markers as predictors of evolution in first psychotic episodes and the modulatory effect of cannabis

The neurones in our brain communicate via receptors and neurotransmitters. Some people who use cannabis or have suffered from psychosis have an increased presence of a special type of receptor for cannabis and serotonin in their neurones. It is possible that the presence of these receptors is related to concentration difficulties, making it harder to keep on top of life, but more research is needed to find out what their function is.

What does the study involve?

The study consists of tests to evaluate your ability to concentrate, a blood test and a cranial MRI. We will also collect a small sample of the olfactory epithelium (similar to a nasal scrape).

The study lasts a total of 4 hours spread over two different days. 

If you are interested in taking part, you can write us an email and we will explain the study in more detail. After checking that you meet the criteria for the study sample, we will invite you to participate in the study.

Clinical projects


Men and women aged between 18 and 35 who regularly use cannabis

  • Written acceptance of informed consent
  • No issues in terms of MRI scanning
  • With or without active cannabis use, but without use of other drugs.
  • Belonging to one of these 3 groups:
    • People who have suffered their first psychotic episode in the last 12 months.
    • People diagnosed with schizophrenia
    • People with no psychiatric history and undergoing no current treatment.
Hospital del Mar Research Institute

Dr. Aiguader, 88, 08003 Barcelona
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Phone: 93 316 04 00 · Fax: 93 316 04 10