Functional Magnetic Resonance Imaging (fMRI) scans measure brain activity from changes in blood flow. fMRI scans have many uses and have allowed researchers to study neural signatures associated with suicidal thoughts, determine the effectiveness of certain treatments on depression, and to determine which areas of the brain are activated during specific activities, to name but a few.
Researchers have also shed light to the effects of drugs on brain activity, with one recent study examining the potential medicinal benefits of cannabis, or more specifically, a constituent of cannabis called cannabidol (CBD).
Cannabidol is a nonintoxicating component of cannabis which has long been thought to have a range of therapeutic properties, including helping to reduce psychotic symptoms. A recent study has helped to explain how cannabidol exerts an effect on the brain and how it could be used as a treatment for patients who are experiencing psychotic symptoms.
The fMRI study was conducted by researchers at King’s College London on 33 participants, none of whom had received a diagnosis of psychosis, but all of whom were experiencing distressing psychotic symptoms. A one-time dose of cannabidol was given to 16 individuals with the remaining 17 given a placebo. The same dose of cannabidol was given to 19 individuals in a control group, none of whom had experienced any psychotic symptoms.
After receiving the treatment/placebo, the study participants were asked to complete memory tasks while undergoing an fMRI scan. The tasks were designed to engage three regions of the brain – the parahippocampal, striatal and midbrain regions – known to be involved in psychosis.
The fMRI scans showed that brain activity in all three areas was abnormal in patients who were experiencing psychotic symptoms, compared to those in the control group. Patients who were given a single dose of cannabidol had their abnormal brain activity reduced to near-normal levels. Cannabidol therefore has considerable potential to be used in the treatment of psychosis to normalize dysfunction.
An alternative treatment is necessary as the drugs currently used to treat people experiencing psychotic symptoms do not work on all patients. “There is an urgent need for a safe treatment for young people at risk of psychosis,” said Sagnik Bhattacharyya, lead author of the study. “One of the main advantages of cannabidiol is that it is safe and seems to be very well tolerated, making it in some ways an ideal treatment.
Use of cannabis has been associated with the development of psychosis, although it is a different compound in the drug – tetrahydrocannabinol (THC)- that is believed to trigger psychosis. THC is the compound that creates the high. CBD does not create a high and has the opposite effect.
The study – Effect of Cannabidiol on Medial Temporal, Midbrain, and Striatal Dysfunction in People at Clinical High Risk of Psychosis: A Randomized Clinical Trial – was recently published in the journal JAMA Psychiatry. doi:10.1001/jamapsychiatry.2018.2309