Scientists have identified neuromarkers of drug use-related affective and cognitive dysregulation that would help healthcare professionals determine individual psychophysiological vulnerabilities to apply personalized treatments.
The study has been published in the Addiction Neuroscience Journal.
Study: Toward neuromarkers for tailored smoking cessation treatments. Image Credit: SOLOVEVAANASTASIIA/Shutterstock.com
Background
Compulsive drug seeking and lack of control over drug intake are the characteristic features of substance use disorders. Any dysregulation in neural networks related to reward and executive control is the leading cause of substance use behaviors.
While excessive incentive salience to drug use-related stimuli contributes to compulsive drug-seeking behaviors, lack of executive control suppresses the ability to control drug intake.
Identifying neuromarkers related to incentive salience and executive control via brain activity assessment has become a major active area of research in addictive neuroscience.
In this study, scientists have discussed methodological paradigms that accurately assess how high incentive salience to drug-related stimuli and lack of executive control influence individual susceptibility to developing substance use disorders.
The scientists have proposed two vital recommendations for identifying appropriate neuromarkers related to substance use behaviors. The first recommendation focuses on considering individual reactivity to non-drug-related motivationally relevant stimuli while assessing individual reactivity to drug-related stimuli.
The second recommendation points out measuring brain activity while participants make drug-related decisions with immediate consequences. Moreover, they have mentioned that validating potential neuromarkers against drug-related behaviors is always important instead of self-reported cravings, as they cannot be objectively assessed.
Important observations
The scientists validated the clinical relevance of their recommendations using nicotine use disorder as a model. They adopted these recommendations while designing the study methodology to identify potential neuromarkers of affective and cognitive dysregulation related to drug use.
The findings indicated the clinical significance of these recommendations in identifying replicable neuromarkers of vulnerability to nicotine self-administration and smoking relapse during a quit attempt.
Using the amplitude of late positive potential (LPP), the scientists measured neurological responses to nicotine-related and non-drug-related stimuli (pleasant images) in 180 smokers during a quitting attempt. LLP is a neuromarker of affective responses modulated by a given stimulus's emotional intensity.
They analyzed LPP responses and identified two neuroaffective reactivity profiles, SCR+ and SCR-. The SCR+ profile indicated larger LPP responses to nicotine-related stimuli than pleasant images. In contrast, the SCR- profile indicated larger LPP responses to pleasant images than nicotine-related stimuli.
Smokers belonging to the SCR+ profile showed a significantly higher frequency of relapse than smokers belonging to the SCR- profile. This observation indicates that these neuroaffecting profiles can effectively determine individual differences in vulnerability to stimuli-induced drug-seeking behaviors.
Based on these findings, scientists mentioned that healthcare professionals could use these neuromarkers to identify individuals more susceptible to repeated drug-addictive behaviors. This would further help them offer personalized treatments to high-risk individuals.
The scientists organized a clinical trial involving nicotine replacement therapy or varenicline, a novel pharmacologic agent that reduces nicotine cravings and withdrawal symptoms and prevents smoking-related rewards.
Preliminary findings of the trial revealed that varenicline is more effective for smokers with the SCR- profile than those with SCR+ profile.
According to the second recommendation, the scientists measured smokers' brain activities (theta wave response patterns) using electroencephalography during the presentation of visual stimuli (drug-related and non-drug-related) and after the delivery of actual rewards.
The scientists identified two neurocognitive profiles based on the theta wave patterns. Smokers with higher theta responses during nicotine-related decision-making were more vulnerable to nicotine self-administration than smokers with the opposite neurocognitive profile.
Study significance
The study identifies specific neuroaffective and neurocognitive biomarkers that can be utilized to develop personalized treatments for various substance use disorders, including tobacco use disorders, alcohol use disorders, and cocaine use disorders.
The US Food and Drug Administration (FDA) recently approved repetitive transcranial magnetic stimulation (rTMS) for smoking cessation.
The scientists believe neuromarkers identified in the study can be used to personalize inhibitory and excitatory rTMS protocols designed to reduce reactivity to drug-related stimuli or increase cognitive control.
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