does weed make you angry

Does Cannabis Make You Grumpy?

One of my coworker’s friends recently asked her whether cannabis can make its consumer “grumpy,” because sometimes he wakes up cranky after an evening of smoking. His timing was serendipitous, as I chanced upon a study from December 2014 that examined the effects of marijuana use on “impulsivity and hostility in daily life.”

For this study, researchers from the Yale University School of Medicine’s Department of Psychiatry and Penn State University’s Department of Psychology collaborated to better understand whether cannabis use affected consumers’ daily experiences. They found 43 participants with no substance dependence and asked them to report on their alcohol consumption, tobacco use, recreational cannabis use, impulsivity, and interpersonal hostility for a period of 14 days.

The participants were a mix of men and women who have previously consumed cannabis and had an alcoholic beverage at least once per week. They weren’t substance dependent, nor did they use any substances aside from cannabis, alcohol, or nicotine. After a phone screening and intake interview, they completed a carbon monoxide test and provided urine samples before being trained on how to complete their daily assessments on a smartphone.

Each night, the participants were prompted to measure the following information:

  • Daily alcohol, tobacco, and cannabis use (how many drinks were consumed, how many cigarettes or cigars were used, and how many “hits” of cannabis were taken and the method of intake)
  • Daily impulsivity as logged by a 7-item short form survey using the “Barratt Impulsiveness Scale-Brief”
  • Daily interpersonal hostility in the form of a survey every time a subject had an interpersonal interaction lasting longer than five minutes

The data showed that impulsivity increased on days cannabis was used compared to days it wasn’t used, and interpersonal hostility increased on use days as well.

According to the study’s findings:

“Our findings support a directional effect on marijuana use on increases in next day impulsivity, a result not previously described in the literature. This is consistent with prior research findings that occasional users of marijuana experience stronger effects of marijuana on attention and inhibition relative to chronic users (Theunissen et al., 2012).”

What’s the science behind this conclusion? The researchers dive into that, too:

“Laboratory studies have found that individuals under the influence of marijuana displayed systematic changes in interpersonal behavior and experience, including a pattern of interpersonal withdrawal, hostility, and diminished interpersonal skills. Despite subjective reports of enhanced sensation and perception, individuals under acute administration of THC showed objective decreases in the number of interpersonal interactions engaged in and the expression of empathetic communications. This suggests that marijuana use has a significant impact on interpersonal behaviors, of which users are not aware. Additional research has found social-emotional deficits in marijuana users, and increases in hostility or aggression.”

The study reports that chronic cannabis consumers have anterior cingulate cortex (ACC) and amygdala deactivation in response to “subconscious presentation of emotional faces,” compared to a control group displaying increased activation. The ACC plays a role in error monitoring, behavioral correction, and inhibition when responding to contextual or environmental changes, so a deactivation of the ACC and the amygdala could “manifest as inappropriate interpersonal responses or altered perceptions of interpersonal behavior in others.” In other words, chronic consumption can be deactivating the part of your brain that keeps your stinkface reaction in check.

So what’s the downside to being a grumpypus? Well, according to researchers, impulsivity is associated with a higher risk for mental health issues, addiction disorders, and risky behavior, while hostility can be tied to cardiovascular risk, stress-related health dysfunction, troubled intimacy, and other aggressive behaviors.

The study, however, is not without flaws. The sample size is incredibly small, and researchers were unable to observe any effects of alcohol use on impulsivity or hostility, despite citing previous studies that have identified such effects (to be fair, another study was cited that also failed to find alcohol effects on risk-taking behavior, though five minutes on YouTube should lend credence to the idea that alcohol and risk-taking behavior are often related).

Second, the researchers conceded that “asking participants to rate their own behaviors may have promoted a level of self-awareness that subsequently impacts either interpersonal behaviors or ratings of behaviors,” and that “future research should examine whether self-monitoring of interpersonal behaviors results in differences in actual behaviors.” In other words, the participants could have been overly self-critical since they knew they had to log their daily behavior for this study. First, the researchers’ primary predictor of interest was whether their subjects reported any cannabis use vs. specific doses, which, as we know, can vary considerably.

Finally, and quite possibly most amusingly, “…individuals may have been intoxicated while completing the surveys and this may have biased the responses for same day effects. Future research should examine whether level of intoxication changes these effects.” Translation: Our subjects could have been super drunk or super stoned or both, so their self-reported data could be skewed.

So does cannabis make you grumpy or not? According to this study, yes, but as with all cannabis findings, more research is needed because the limited number of studies that exist are only able to tell us a partial story. Also, this study was narrow in its scope and flawed in its methodology, which is another reason why we need more research so we can test, re-test, and test some more until we’re able to come to more confident conclusions. Re-scheduling cannabis would be a huge step in the right direction, as it would open up more research avenues.

Time for you to weigh in! In your personal experience, have you noticed your mood turning sour after chronic cannabis consumption, or is the outcome of this study the only thing making you angry right now?

Researchers from Yale and Penn State University collaborated to better understand whether cannabis use affected consumers' daily experiences, including impulsivity and hostility.

Can cannabis cause mania and angry rages?

Alyssa Holley

It’s common knowledge that the effects of cannabis can make most users chilled out and relaxed, however many would agree that when wondering about the other effects, anger and rage would be a less assumed.

Recent reports have stated that cannabis can be a common cause for symptoms of mania, rage and anger, with the Guardian newspaper revealing a story on a 25-year-old who commonly has anger issues in connection with his cannabis addiction.

“I have a 25-year-old son, the younger of two. I believe he is addicted to cannabis, which he says he needs to combat his anxiety. He doesn’t work and has episodes of rage. I help him as much as I can financially without physically handing him cash. When I can’t help him, he turns on me. He threatens me, saying things such as: ‘I don’t want to live any more’,” the mother of the subject explains.

Often addiction can happen as a result of the individual seeking to use the drugs as a coping mechanism for underlying issues or mental problems, in which using a substance can help the person feel better in the short-term without having to directly deal with the initial problem.

The anger this person is experiencing may have more to do with the underlying issue of anxiety and feelings of uselessness that often come as a result of anxiety, as well as not having a job and relying on parents.

This is not the only time reports have distinguished a link between cannabis abuse and angry rages, with a lead researcher at Warwick University stating that cannabis can bring on symptoms of mania.

Critical period

“Cannabis is the most prevalent drug used by the under-18s,” he said.

“During this critical period of development, services should be especially aware of and responsive to the problems cannabis use can cause for adolescent populations.”

“Previously it has been unclear whether cannabis use predates manic episodes.”

However new research states there is a “significant link” between cannabis consumption and manic episodes.

It also presented a link between cannabis use and the potential onset of bipolar disorder, although the reports admits “more research is needed to consider specific pathways from cannabis use to mania”.

The report also noted that cannabis use significantly worsened mania symptoms in people who had previously been diagnosed with bipolar disorder, adding to the theory that the cannabis itself would not create mania for an individual with no underlying issues but rather exacerbates a previously existing issue.

However, in spite of the negativity from the report in terms of the potential impact on mental illnesses, it claims that consuming cannabis can aid symptoms of depression as long term stress can reduce the amount of endocannabinoids in the brain, which ultimately affect motor control, cognition, emotions and behaviour.

The endocannabinoid (EC) system is a communications system in the body and brain that affects how someone feels, moves and reacts. The EC system is active in every person’s body even if they don’t and have never used cannabis.

Endocannabinoids are molecules created by the body, which bind to receptors in the EC system and signal actions that the body needs to take, such as reliving pain or signal to the body when there is inflammation somewhere.

Endocannabinoid levels

Endocannabinoids are very similar to the chemicals present in cannabis and its most well-known active component – delta-9-tetrahydrocannabinol (THC) – which means that these external cannabinoids could potentially be used to restore the lost endocannabinoid levels in the brain in those who have suffered these affects due to long-term stress or depression.

It appears that the cannabis may not be causing mania or rage directly, but that the individuals who are experiencing these symptoms may be suffering from mental health issues regardless of the cannabis use, and using something that has documented mental-related effects may be exacerbating the underlying mental issues.

A similar argument is made for cannabis use causing psychotic disorders, in which it can seem easy to draw conclusions that this is true. However, most arguments fail to make the connection between those who are susceptible to psychosis or schizophrenia may demonstrate problematic behaviour such as smoking, abusing drugs and having poor school performance before the cannabis use has started.

The cannabis use in this case is another issue on top of the underlying problems already present, which is a result of the psychotic disorder instead of being the sole causation of it.

Research from the Alcohol and Drug Institute at Washington University also noted a link between cannabis and aggressive behaviour, although it specifically attributed to fits of anger occurring when someone was withdrawing from the drug.

The common perception is that cannabis is not physically addictive and that withdrawal doesn’t come with physical side effects. The report states that users can experience sleep disturbance, nausea, irritability, loss of appetite, sweating and anxiety, all of which could contribute to feelings of anger and aggression.

History of aggression

Someone withdrawing from heavy cannabis use is oftentimes irritable, which can subsequently lead to a higher likelihood of becoming aggressive in those who have a history of aggression.

The report goes on to explain that despite some evidence to show an association between cannabis and violence, there is no definitive correlation between the two and that the violence displayed by cannabis users and non-users often has a multitude of different causes, such as increased life stress, aggressive personality traits, multi drug use and a history of violent behaviour.

Another recent study conducted by Yale researchers found a link between cannabis use and aggressive behaviour in a specific gene which is responsible for regulating cannabis-induced aggression.

Despite the study being limited as it was conducted solely on mice, it demonstrates the potential aggressive response being linked to an individual genetic make-up, in that those subjects who had a missing 2B serotonin receptor gene were more likely to exhibit hyperactivity, aggression and impulsivity.

With more light being shed on the topic, the most recent findings demonstrate a need to study the links further in order to come to a concrete conclusion, as new information opens doors for further research, as reiterated by Juanita Montalvo-Ortiz, Assistant Professor of Psychiatry at the Yale School of Medicine.

Montalvo-Ortiz concluded that: “I think there’s a lot of research that could be done. This is just the tip of the iceberg, and it deserves deeper understanding.”

Recent reports have stated that cannabis can be a common cause for symptoms of mania, rage and anger among regular users – but what are the facts?