Cannabis use is steadily rising among college students. As legalization expands and stigma fades, marijuana has become a normalized part of student life from dorm rooms to parties and even casual hangouts. Alongside this shift, conversations about personal boundaries and sexual ethics are also evolving. Yet while alcohol has long been a focus in campus discussions around consent, cannabis often remains an afterthought.
That needs to change. THC, the psychoactive compound in cannabis, affects critical cognitive functions like judgment, memory, emotional awareness, and communication. All of these are vital for giving, and recognizing clear and meaningful consent. In an era of changing norms, students need better tools and language to navigate the gray areas that cannabis can create in intimate situations.
Understanding Consent: Clear, Freely Given, and Informed
Consent, at its core, must be clear, voluntary, and informed. It’s not something to assume based on mood, past experience, or body language. It’s a mutual agreement made when both people are capable of understanding the situation and their own feelings about it. This means that consent must be given in a sober, coherent state. Someone who is significantly impaired, whether by alcohol, cannabis, or anything else, cannot give valid consent.
While cannabis might make someone feel relaxed, open, or even affectionate, those emotional effects are not the same as genuine, conscious agreement. The moment substances affect a person’s capacity to assess risk, communicate clearly, or understand what’s being asked of them, the conditions for true consent start to break down.
The Physiological Effects of THC on Cognitive Function
Understanding why requires a look at how THC works in the brain. When someone consumes cannabis, THC binds to receptors in parts of the brain that control memory, decision-making, and emotional regulation. As a result, people may find it harder to track conversations, evaluate outcomes, or interpret social cues. The sativa doesn’t make people sleepy, but the indica stain of marijuana does: not a good effect for consent.
Several specific impairments often occur with cannabis use. Short-term memory may become unreliable, which can lead someone to forget what they said or agreed to just minutes earlier. Decision-making is dulled; users tend to become more impulsive and less aware of long-term consequences. Social perception is also affected, which means a person might miss or misread signs of discomfort, or interpret friendliness as flirtation. Emotional interpretation can become skewed, too. THC can make experiences feel more intense or confusing than they really are. And time perception often becomes distorted, making it difficult to understand how fast or slowly events are unfolding.
A study in JAMA Psychiatry found that cognitive impairments from cannabis use can last for several hours after consumption. Importantly, these effects were present even in moderate doses, and even when users no longer “felt high.” So even if someone appears lucid, their internal cognitive function may still be altered in ways that matter.
Judgment and Communication Under the Influence
When it comes to real-life sexual situations, these effects can create serious misunderstandings or risks. Someone under the influence may agree to something they wouldn’t while sober not out of true willingness, but because their usual sense of boundaries is dulled. They may struggle to express discomfort or say “no” clearly. They may believe they’re fine to proceed, even if their ability to reflect on the situation is impaired.
The other person in the situation may face their own challenges, especially if they are less impaired or completely sober. Cannabis can make a partner appear more relaxed or enthusiastic than they actually are. In these cases, relying on vague cues, like body language, tone, or past behavior, can easily lead to misinterpretation. Without direct, verbal communication, assumptions can fill the gaps, and that’s where the risks escalate.
The Risk Factor: When Impaired Judgment Meets Sexual Situations
This dynamic becomes especially risky when both people are under the influence. With mutual impairment, communication often drops off entirely. Neither person may be thinking clearly or able to set or interpret boundaries. While there may be no intent to cause harm, the conditions are ripe for confusion, regret, and sometimes even sexual assault.
Real-world statistics reflect this concern. A 2019 survey from the Association of American Universities reported that 26% of undergraduate women and nearly 7% of men experienced nonconsensual sexual contact during college often involving situations where the victim could not consent due to intoxication. While alcohol is still the most common factor, cannabis is increasingly part of the picture. A study published in Addictive Behaviors in 2018 found that nearly half of young adult cannabis users reported having sex while high, and many described lower awareness and communication during those encounters.
This isn’t about demonizing cannabis. Plenty of people use it responsibly. But in the context of sex and consent, even mild impairment matters. A calm, relaxed demeanor isn’t enough to assume someone is thinking clearly or able to communicate what they really want. For that reason, the safest approach is to wait until both people are fully sober before engaging in anything intimate.