Convergent evidence suggests a link between cannabis use and psychosis. However, cannabis comprises a combination of cannabinoids and these different constituents may have distinct effects, not all of which are detrimental to mental health. the main component of smoked cannabis is D9-tetrahydrocannabinol (D9-THC), which is thought to be responsible for the majority of the psychotomimetic effects of the drug: it has been shown to elevate levels of anxiety and psychotic symptoms in healthy individuals. In contrast, cannabidiol (CBD), another major constituent of some strains of cannabis, has been found to be anxiolytic and to have antipsychotic properties, and may be neuroprotective in humans. the ratio of these two compounds in smoked cannabis varies – there are higher levels of D9-THC in ‘skunk’ or genetically modified strains of the plant. Cannabis users are often unaware of the ratio of CBD to D9-THC because CBD has no psychotomimetic effect in humans. Elevated levels of psychosis proneness and delusions have been found in people who use cannabis regularly. despite suggestions about the different psychological properties of these two constituents of smoked cannabis, no prior research has examined the link between psychosis proneness and delusions and the CBD/D9-THC ratio in those who use cannabis. This study aimed to use hair analytic techniques to examine levels of D9-THC and CBD, and relate these objective indices of cannabis use to measures of psychosis proneness and delusional thinking.

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Copyright: the British Journal of Psychiatry

Schizophrenia is a debilitating mental disorder affecting one in 100 people worldwide. most cases are not detected until a person starts experiencing symptoms like delusions and hallucinations as a teenager or adult. by that time, the disease has often progressed so far that it can be difficult to treat.

In a paper published recently online by the American Journal of Psychiatry, researchers at the University of North Carolina at Chapel Hill and Columbia University provide the first evidence that brain abnormalities associated with schizophrenia risk are detectable in babies only a few weeks old.

“It allows us to start thinking about how we can identify kids at risk for schizophrenia very early and whether there things that we can do very early on to lessen the risk,” said lead study author John H. Gilmore, MD, professor of psychiatry and director of the UNC Schizophrenia Research Center.

The scientists used ultrasound and MRI to examine brain development in 26 babies born to mothers with schizophrenia. Having a first-degree relative with the disease raises a person’s risk of schizophrenia to one in 10. among boys, the high-risk babies had larger brains and larger lateral ventricles—fluid-filled spaces in the brain—than babies of mothers with no psychiatric illness.

“could it be that enlargement is an early marker of a brain that’s going to be different?” Gilmore speculated. larger brain size in infants is also associated with autism.

The researchers found no difference in brain size among girls in the study. this fits the overall pattern of schizophrenia, which is more common, and often more severe, in males.

The findings do not necessarily mean the boys with larger brains will develop schizophrenia. Relatives of people with schizophrenia sometimes have subtle brain abnormalities but exhibit few or no symptoms.

“this is just the very beginning,” said Gilmore. “We’re following these children through childhood.” The team will continue to measure the children’s brains and will also track their language skills, motor skills and memory development. they will also continue to recruit women to the study to increase the sample size.

This research provides the first indication that brain abnormalities associated with schizophrenia can be detected early in life. Improving early detection could allow doctors to develop new approaches to prevent high-risk children from developing the disease. “The research will give us a better sense of when brain development becomes different,” said Gilmore. “And that will help us target interventions.”

Material adapted from University of North Carolina School of Medicine by CFisher.