Many of us know the feeling: a sudden rush of anger over a seemingly minor thing like a colleague’s irksome email, getting a customer service bot, seeing dishes in the sink or bumper-to-bumper traffic when you’re running late. Disproportionate reactions follow, and it can be easy to snap at a loved one or excessively honk the car horn. Such irritable outbursts may be especially rife now due to heightened stress during the holidays.
Defined as an excessive propensity to anger, irritability is often triggered by perceived threats or frustration around things not going our way. And whenever you feel it, you’re not alone. In a 2024 survey of nearly 43,000 adults in the United States, participants on average rated their irritability at 13.6 on a scale of 5 (never feeling irritable at all) to 30 (feeling highly irritable all the time).
As the survey underscores, irritability is a common — and often normal — response to situations that are, well, irritating.
But irritability can become a real burden. It can make some people constantly cranky or prone to frequent or extreme anger outbursts. Just like sadness and nervosity can escalate into depression or anxiety, “[irritability] becomes pathological when it either causes someone great distress or it interferes with their functioning,” says Roy Perlis, a psychiatrist at Massachusetts General Hospital in Boston who conducted the survey, published in Neuropsychopharmacology. “As a physician, I see it every day in clinic. People come in and they complain that they’re irritable as much as they complain about being depressed or being anxious.”
Yet irritability has long been a neglected phenomenon in adults; research on the emotional state has largely focused on children and teenagers, where it’s a core symptom of a severe mood disorder involving explosive tantrums. Now, scientists are beginning to turn their attention to adults, searching for clues as to why some people become so cranky — and what they can do about it.
Roots of irritation
Irritability is deeply baked into our behavior — and we’re not the only animals to experience it.
Some scientists study the biological roots of irritability by intentionally frustrating mice. One way is to withhold a treat after training the rodents to expect a reward upon pressing a lever, says neuroscientist Wan-Ling Tseng of Yale School of Medicine. Frustrated mice press harder and longer on the lever — not unlike people aggressively jabbing the button of an overly slow elevator. And like irritable humans, “the frustrated mice are more likely to show aggression,” Tseng says.
These similarities across species underscore that irritability is a deep-rooted response. Tseng speculates that the reaction may be even an evolutionarily beneficial one, helping animals get what they need or want.
“Being irritable is not a character flaw. It is something people can learn to manage, but sometimes, some people will need additional help to learn to manage it.”
Roy Perlis
Psychiatrist, Massachusetts General Hospital
However, irritability can be a cause for concern when it causes someone distress. It can be upsetting to spend one’s day grumbling or having uncontrollable anger outbursts, Perlis says.
“Someone who is so irritable that they start arguments with coworkers, or even people they encounter on their way to work, is someone where we might consider the irritability to be pathological,” Perlis says. If people often find themselves thinking, “I wish I hadn’t said that, I wish I hadn’t done that,” Perlis says, “that’s one red flag.”
Clinical psychologist Maria Gröndal of Sweden’s University of Gothenburg has observed great distress among women with premenstrual dysphoric disorder, or PMDD, who often suffer from extreme irritability before their period begins. Many get into heated arguments with their partners or children. And when they do try to contain their temper, this can take a lot of energy and interfere with their ability to focus on work or other tasks, Gröndal says.
How irritability looks in the brain
What makes some adults more prone to extreme irritability than others is still a mystery. But some clues may come from studies in younger people.
The brains’ threat- and reward-processing systems seem to operate differently in children and adolescents with high irritability. In a 2018 study in American Journal of Psychiatry, Tseng and her colleagues had 195 children and teenagers play a computer game that was designed to frustrate them by unfairly subtracting points. Compared with even-tempered kids, the brains of those with irritable tendencies showed a heightened activity in the striatum, a key reward-processing region, when they became frustrated.
The team also found unusual responses in brain regions important for executing tasks, which helps explain why moody kids have a hard time focusing when they’re frustrated. Other research has documented unusual activity in the amygdala — the brain’s threat-processing center — in highly irritable kids.
While scientists are still scrutinizing the brains of irritable adults, research so far suggests that the same brain regions are involved. “What we see is that the brain circuits related to reward and threat are implicated,” says Manish Jha, a psychiatrist at UT Southwestern Medical Center in Dallas.
What causes these kinds of brain responses is still not clear, but research points to underlying health conditions as one possible factor. Irritability has been likened to a fever — a general sign that something in the brain or body is out of balance, such as in many mental health disorders, Gröndal says. For instance, about half of adults who have depression — and up to 90 percent of youth with anxiety — report being highly irritable.
These conditions may often occur together because irritability — which is moderately heritable — arises from the same genetic factors as depression and anxiety. Or, it could have to do with the fact that all three conditions have been linked to dysfunctions in people’s threat and reward systems, Tseng says.
Notably, frequent irritability is a risk factor for developing suicidal thoughts, Jha and colleagues reported in 2020 in Neuropsychopharmacology. It’s such a reliable factor, in fact, that Jha is exploring using irritability as a way of gauging the risk of depressed people experiencing an increase in suicidal thoughts. Irritability also pops up in conditions like attention-deficit/hyperactivity disorder and bipolar disorder, and in women undergoing hormonal fluctuations, including during the period leading up to menopause.
Problematic anger tendencies in general — including irritability — are also common in people who have experienced traumatic events such as physical abuse and get “stuck” in feelings of anger, says Olivia Metcalf, a behavioral scientist at the University of Melbourne in Australia.
Perlis notes, though, that extreme irritability doesn’t always signal a deeper mental health condition; in some cases it could just boil down to temperament. In his survey, a small percentage of people who didn’t have anxiety or depression, for instance, were extremely irritable. Factors like being sick, stressed, sleep-deprived, hungry, in pain, lonely or in the process of giving up smoking, can also make people cranky or exacerbate irritability in those who are already moody. And Perlis recently documented a strong association between irritability and social media use, perhaps in part because excessive scrolling could make people feel worse.
Relieving irritability
Whatever the underlying cause, scientists have recognized the importance of finding treatments for people with impairing levels of irritability.
Some researchers are investigating a nose spray containing the “love hormone” oxytocin, which has shown some promise in treating certain irritable kids and teens ages 10 to 18 years. Tseng, meanwhile, is currently testing a technique called transcranial magnetic stimulation — placing a coil around people’s heads that releases magnetic pulses — to restore normal activity in reward-processing brain regions.
For now, Jha recommends anyone with severe irritability to see a mental health professional to get a full psychiatric evaluation to see if they have underlying mental health conditions; treating these can often help reduce crankiness.
In a 2020 study, Jha and his colleagues observed that giving depressed adults antidepressants not only lowered their irritability symptoms, but — perhaps by virtue of lowering their irritability, Jha suspects — subsequently also their levels of suicidal ideation.
Antidepressants called selective serotonin reuptake inhibitors also have proven remarkably useful in reducing aggressive behavior in PMDD–afflicted women when they receive the medications in the days leading up to their period, says Gröndal. Her 2025 study found the treatment was especially effective in women who tended to express their anger outwardly rather than bottling it up.
Cognitive behavioral therapy, a kind of talk therapy, can also help treat irritability by teaching people to pick up on early signs of anger and find constructive ways to manage their aggressive impulses, Perlis says.
Metcalf has found promise for an even simpler approach. In a 2025 study in JMIR Human Factors, she and her colleagues gave 98 anger-prone trauma survivors a smartphone app that prompted them four times a day to evaluate their anger levels. They were also given a simple wearable device to track their heart rate and blood pressure, both of which can indicate stress levels.
While people with problem anger often focus on triggers in their environment, the simple act of self-reflection helped them direct their attention inward. They were able to recognize impending anger episodes — by tracking both emotional and physiological changes — and take action to calm themselves down, for instance through breathing techniques, removing themselves from triggering situations or reminding themselves that the annoying behaviors of others aren’t intentional. “We saw this really big reduction in their problem anger,” Metcalf says.
Irritable people who feel prone to anger outbursts can do this by setting a timer to remind themselves to regularly screen their mental and bodily state for signs of increasing anger. “Am I holding tension in my muscle that I’m not even noticing? Are my teeth gritted? Do I feel a palpitation or a tightness in my chest?” Metcalf asks.
Being aware of external factors that can exacerbate irritation, like hunger or being sleep-deprived, is also crucial. That way, people can address those factors wherever possible, Jha says.
Science reveals that being anger-prone doesn’t mean we need to get angry, Perlis says. “Being irritable is not a character flaw,” he says. “It is something people can learn to manage, but sometimes, some people will need additional help to learn to manage it.”
If you or someone you know is facing a suicidal crisis or emotional distress, call or text the 988 Suicide & Crisis Lifeline at 988.
