Investigating the Role of the Endocannabinoid System in Early Psychosis

TY - JOUR

T1 - Investigating the Role of the Endocannabinoid System in Early Psychosis

AU - O'Neill, Aisling

AU - Bhattacharyya, Sagnik

PY - 2017/7/21

Y1 - 2017/7/21

N2 - Accumulating evidence suggests that dysfunction within the endocannabinoid (eCB) system may play a role in psychosis. However, little is understood about how this may be related to the neurocognitive abnormalities and symptoms of psychosis. In this paper, we summarize some of the evidence supporting the role of eCB system in psychosis, as well as the current understanding of the neurocognitive underpinnings of psychosis. We particularly focus on neuroimaging evidence pertaining to alteration in the functional integration between different brain regions in patients with psychosis, and then relate this to evidence from neuroimaging studies of the effects of cannabis and its main ingredients, such as delta-9-tetrahydrocannainol and cannabidiol. Specifically, we explore this in the context of the hypothesis that psychosis is a disorder of dysconnectivity between different brain regions, focusing particularly on three large scale functional networks (the default mode, central executive, and salience networks), alterations in which have been implicated in psychosis, and we discuss the gaps in this research thus far. Finally, we propose that an approach to investigating the role of the eCB system in psychosis may be to employ a pharmacological cannabinoid challenge paradigm to examine how experimental perturbation of the eCB system may be related to abnormalities in the brain networks implicated in psychosis. We discuss challenges associated with this approach, and suggest safe and practical options to overcome the main issues involved with such an experimental approach. Studies employing such an approach have the potential of offering insight into the neurocognitive mechanisms underlying psychosis, and identifying novel therapeutic targets.

AB - Accumulating evidence suggests that dysfunction within the endocannabinoid (eCB) system may play a role in psychosis. However, little is understood about how this may be related to the neurocognitive abnormalities and symptoms of psychosis. In this paper, we summarize some of the evidence supporting the role of eCB system in psychosis, as well as the current understanding of the neurocognitive underpinnings of psychosis. We particularly focus on neuroimaging evidence pertaining to alteration in the functional integration between different brain regions in patients with psychosis, and then relate this to evidence from neuroimaging studies of the effects of cannabis and its main ingredients, such as delta-9-tetrahydrocannainol and cannabidiol. Specifically, we explore this in the context of the hypothesis that psychosis is a disorder of dysconnectivity between different brain regions, focusing particularly on three large scale functional networks (the default mode, central executive, and salience networks), alterations in which have been implicated in psychosis, and we discuss the gaps in this research thus far. Finally, we propose that an approach to investigating the role of the eCB system in psychosis may be to employ a pharmacological cannabinoid challenge paradigm to examine how experimental perturbation of the eCB system may be related to abnormalities in the brain networks implicated in psychosis. We discuss challenges associated with this approach, and suggest safe and practical options to overcome the main issues involved with such an experimental approach. Studies employing such an approach have the potential of offering insight into the neurocognitive mechanisms underlying psychosis, and identifying novel therapeutic targets.

U2 - 10.14218/JERP.2017.00009

DO - 10.14218/JERP.2017.00009

M3 - Review article

VL - 2

SP - 67

EP - 74

JO - Journal of Exploratory Research in Pharmacology

JF - Journal of Exploratory Research in Pharmacology

IS - 3

ER -