Cannabis, one of the most commonly used psychoactive substances globally, has garnered significant attention due to its potential impact on brain structure and function. In 2018, the United Nations estimated that 3.9% of the global population aged 15–65 had used cannabis, with 9.9% of them being daily or near-daily users.
Chronic cannabis use has raised concerns about its effects on the brain, particularly in relation to the binding mechanism between Δ9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, and Cannabinoid CB1 brain receptors.
Studies have indicated that chronic cannabis use may lead to decreased availability of CB1 receptors, particularly in the anterior cingulate cortex (ACC), a region associated with a wide range of cognitive and affective functions.
The ACC, which contains a high concentration of CB1 receptors, is considered a key hub in the salience network, playing a crucial role in processing external and internal stimuli to maintain homeostasis and assign positive or negative valences. It is involved in conflict detection, empathy, and various other functions related to cognitive and emotional processing.
Recent research has demonstrated the potential consequences of chronic cannabis use on the ACC, including altered resting-state functional brain activity and structural changes. These alterations extend to regions like the insula, thalamus, striatum, and left sensorimotor cortex.
This article explores the impact of chronic cannabis use on empathy and ACC connectivity, shedding light on the complex relationship between cannabis consumption and social and emotional processing.
Empathy and the ACC
Empathy, a complex cognitive and emotional process, involves understanding and sharing the emotional experiences of others. It encompasses the ability to perceive and comprehend the feelings of others, especially in moments of suffering, and it plays a significant role in promoting prosocial behavior. The ACC, in conjunction with other brain regions, has been identified as a core network for empathy.
Chronic Cannabis Use and ACC Alterations
Recent studies have investigated the effects of chronic cannabis use on the ACC, particularly in the context of empathy. While extensive research has explored the cognitive and affective implications of cannabis consumption, the impact on empathy-related processes has received relatively less attention.
A study by Roser et al. (2012) examined functional brain activation in cannabis users during a perspective-taking task, a cognitive component of empathy. The results showed that regular cannabis users exhibited greater activation in the left cuneus and the right anterior cingulate gyrus compared to non-users. These findings hinted at potential alterations in social cognition related to the attribution of others’ mental states, with the ACC displaying differentiated functional activation in cannabis users.
Cannabis and Empathy-Related Psychometric Differences
To gain a deeper understanding of the relationship between chronic cannabis use and empathy, it is essential to assess empathy-related psychometric differences. While limited research has focused on this aspect, there are indications that regular cannabis users may exhibit unique patterns in empathy-related measures. For instance, some studies have reported higher levels of prosocial behaviors, benevolence, fairness, and empathy among cannabis users compared to non-users.
Functional Connectivity of the ACC in Cannabis Users
In addition to evaluating psychometric differences, it is crucial to investigate the functional connectivity of the ACC in cannabis users. Understanding how the ACC interacts with other brain regions, especially within the empathy core network, can provide valuable insights into the effects of chronic cannabis use on social and emotional processing.
Enhanced Emotional Comprehension in Cannabis Users:
The study’s primary revelation that regular cannabis users exhibited higher levels of emotional comprehension compared to non-users sheds light on the complex interplay between cannabis consumption and empathetic abilities. Emotional comprehension, a critical aspect of cognitive empathy, relates to an individual’s capacity to recognize and understand the emotional states of others. This phenomenon aligns with similar findings reported by Vigil et al. (2022), where cannabis users displayed a heightened ability to perceive and interpret the emotions of others.
Furthermore, previous research has linked these psychometric findings to subjective experiences and behaviors exhibited by cannabis users. These behaviors include a greater understanding of others’ emotions, reduced verbal hostility, enhanced prosocial tendencies, and an increased empathetic disposition towards others’ situations. This is supported by studies conducted by Georgotas and Zeidenberg (1979), Salzman et al. (1976), and Tart (1970).
Brain Connectivity and Emotional Comprehension:
The study’s findings suggest a potential link between the enhanced emotional comprehension in cannabis users and increased functional connectivity (FC) between the anterior cingulate cortex (ACC) and the bilateral somatomotor cortex (SMC). The SMC, known for processing somatosensory information and representing others’ somatosensory states, plays a pivotal role in this context.
Studies have previously indicated that the activation of the somatosensory cortex is associated with heightened attention to one’s own emotional experiences. Additionally, these regions have been implicated in the simulation of others’ actions and emotions, emphasizing their role in understanding and connecting with the emotions of others.
This enhanced connectivity may add a somatosensory dimension to the representation of others’ emotions, which could contribute to the greater emotional comprehension seen in cannabis users. This notion is further supported by differences in the empathy core network (ECN), where cannabis users displayed increased connectivity between the ACC and the left anterior insula (lAi), along with overall stronger ECN connectivity.
Contrasting Findings and the Multimodal Effects of Cannabis:
While the study’s results contrast with research reporting deficits in emotional detection among chronic cannabis users, it’s important to acknowledge that the effects of cannabis consumption may be multifaceted and context-dependent. Chronic cannabis consumption may have diverse impacts, encompassing negative behaviors such as emotional dysregulation or social stress, as well as positive behaviors like social bonding and social reward. These varying effects may explain the divergence in findings across different studies (MacKenzie & Cservenka, 2023; Troup et al., 2016; Gruber et al., 2009; Wesley et al., 2016; Wei et al., 2017).
The Role of CB1 Receptors and Future Research Directions:
The ACC, one of the primary areas housing CB1 receptors, is intricately involved in representing the affective states of others. It is plausible that the differences observed in emotional comprehension scores and brain functional connectivity in regular cannabis users may be linked to their cannabis use. However, it is crucial to consider the possibility that these differences existed before cannabis use began.
The study’s reliance on subjective reports related to cannabis and other substance consumption is a limitation that could be addressed in future research by incorporating biochemical markers to more accurately assess the consumption profiles of participants. Additionally, the differences in THC concentrations between US and Mexican cannabis may have influenced the study’s outcomes, as lower-quality cannabis in Mexico may lead to different functional brain responses.
A further limitation is the absence of a comprehensive personality trait assessment, which has been shown to be correlated with substance consumption. Exploring gender differences in functional connectivity and empathic traits among cannabis users could also provide valuable insights.
The impact of chronic cannabis use on the brain, specifically on the anterior cingulate cortex, remains a complex and evolving field of study. While research has highlighted alterations in ACC function related to empathy and social cognition in cannabis users, more comprehensive studies are needed to fully comprehend the nuances of this relationship. It is clear that cannabis affects cognitive and emotional processes differently in various individuals, making it challenging to draw overarching conclusions.
As cannabis legalization continues to gain momentum globally, it is imperative to explore the long-term effects of chronic cannabis use, especially concerning its impact on social and emotional functions. By further investigating the psychometric and neural differences in empathy-related processes, researchers can contribute to a better understanding of the potential consequences of cannabis use, leading to more informed policies and interventions in the future.
reference link : https://onlinelibrary.wiley.com/doi/10.1002/jnr.25252