Do reward-processing deficits in schizophrenia-spectrum disorders promote cannabis use? An investigation of physiological response to natural rewards and drug cues.
|Title||Do reward-processing deficits in schizophrenia-spectrum disorders promote cannabis use? An investigation of physiological response to natural rewards and drug cues.|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Cassidy CM, Brodeur MB, Lepage M, Malla A|
|Journal||J Psychiatry Neurosci|
|Date Published||2014 Sep|
|Keywords||Adult, Brain, Cannabis, Cues, Electroencephalography, Electromyography, Evoked Potentials, Visual, Facial Muscles, Galvanic Skin Response, Heterosexuality, Humans, Male, Marijuana Abuse, Neuropsychological Tests, Photic Stimulation, Prognosis, Psychotic Disorders, Reward, Schizophrenic Psychology, Tobacco Use Disorder, Visual Perception|
BACKGROUND: Dysfunctional reward processing is present in individuals with schizophrenia-spectrum disorders (SSD) and may confer vulnerability to addiction. Our objective was to identify a deficit in patients with SSD on response to rewarding stimuli and determine whether this deficit predicts cannabis use.METHODS: We divided a group of patients with SSD and nonpsychotic controls into cannabis users and nonusers. Response to emotional and cannabis-associated visual stimuli was assessed using self-report, event-related potentials (using the late positive potential [LPP]), facial electromyography and skin-conductance response.RESULTS: Our sample comprised 35 patients with SSD and 35 nonpsychotic controls. Compared with controls, the patients with SSD showed blunted LPP response to pleasant stimuli (p = 0.003). Across measures, cannabis-using controls showed greater response to pleasant stimuli than to cannabis stimuli whereas cannabis-using patients showed little bias toward pleasant stimuli. Reduced LPP response to pleasant stimuli was predictive of more frequent subsequent cannabis use (β = -0.24, p = 0.034).LIMITATIONS: It is not clear if the deficit associated with cannabis use is specific to rewarding stimuli or nonspecific to any kind of emotionally salient stimuli.CONCLUSION: The LPP captures a reward-processing deficit in patients with SSD and shows potential as a biomarker for identifying patients at risk of heavy cannabis use.
|Alternate Journal||J Psychiatry Neurosci|
|PubMed Central ID||PMC4160363|
|Grant List||/ / Canadian Institutes of Health Research / Canada|