The study providing that the first evidence of a blunting response to stress inducing dopamine signaling; in the brain’s prefrontal cortex in individuals at high risk for psychosis who regularly using cannabis. But the little is knowing about the effects of cannabis on brain neurochemistry; and specifically about its impact on dopamine signaling.
Cannabis is one of the most widely using recreational drugs world wide and the most commonly using illicit drug in patients on the psychosis spectrum including those with schizophrenia and those at elevated risk. The longitudinal studies link cannabis use to a significantly; that increasing risk of subsequent development of psychotic symptoms or psychotic illness.
As the stress and cannabis use are risk factors for the development of psychosis. We have previously shown that subjects at clinical high risk for psychosis exhibit a higher striatal dopamine response to stress compared with healthy volunteers; with chronic cannabis use blunting this response. However, it is unknown if this abnormal dopamine response extends to the prefrontal cortex.
Risk for psychosis using cannabis
Drugs of abuse such as cocaine, amphetamine, methamphetamine, and alcohol are associating with decreasing striatal dopamine release when using regularly. This has also been reporting for individuals with cannabis dependence showing blunting dopamine release in stria-tum upon amphetamine challenge compared with non‐users and for cannabis abusers showing a blunted dopamine response in stria-tum after methylphenidate challenge compared with non‐user’s people.
But the recent analysis found a dose response relationship between higher cannabis use and increased risk for schizophrenia, a condition associated with abnormal dopamine synthesis and release in the brain. Moreover, cannabis users at clinical high risk for psychosis had lower stress‐induced striatal dopamine release as compared with non‐users, which was associating at trend level with the age of onset of cannabis use in associative striatum.
The neurocognitive functions
Cannabis use is associated with deficits in both emotional processing; and neurocognitive function; consistent with observations in patients with schizophrenia. This latest study’s results are important giving the global trend to legalize cannabis and the growing evidence of the increasing risks for psychosis in vulnerable youth. However, it is unknown if this abnormal dopamine response extends to the prefrontal cortex.
Regular cannabis use has a profound effect on cortical dopamine function; in particular in relation to the stress response, which is critical for young adults at risk for psychosis. These results highlight the need for further research on the impact of cannabis on brain neurochemistry; especially in populations at risk for psychosis.