How common is irritability in U.S. adults and what factors are linked to it?

By Dr. Sanchari Sinha Dutta, Ph.D.Aug 26 2024

Study: Prevalence and correlates of irritability among U.S. adults. Image Credit: TeodorLazarev / Shutterstock

Researchers analyzed an extensive survey of U.S. adults, finding that irritability is common and strongly associated with higher risks of depression, anxiety, and suicidal thoughts, particularly among women, younger individuals, and those with lower education and income levels.

A recent study published in the journal Neuropsychopharmacology reveals that higher levels of irritability can significantly trigger suicidal thoughts in adult individuals.

Background

Irritability is considered a feature of a psychiatric disorder in modern psychiatry. Around 50% of individuals with major depression have been found to experience significant irritability. Moreover, a genetic correlation between depression and irritability has also been found in the literature.

In this context, evidence indicates that the co-existence of depression and irritability can lead to anxiety issues, poor functioning and quality of life, poor treatment outcomes, and higher suicide risks.

In children and adolescents, irritability has been found to increase the risk of mood and anxiety diagnoses later in life. However, despite the significant influence of irritability on mental health, few studies investigating how and where irritability manifests among adults in the general population are currently available.      

In this study, scientists have determined the prevalence of irritability among adults in the United States. They have also assessed the co-existence of irritability with major depressive and anxiety symptoms in the U.S. general population.

Study design

The study analyzed data from two waves of a non-probability web-based survey conducted in 50 U.S. states and the District of Columbia between November 2023 and January 2024. The survey was conducted during the COVID-19 pandemic, a period noted for heightened levels of depressive symptoms. This nationally representative survey population included 42,739 adults.

Appropriate statistical analyses were carried out to determine the associations of irritability with major depression, anxiety, and suicidal thoughts. The prevalence and sociodemographic correlates of irritability were also assessed in the study.

Important observations

The study population included 58.5% women, 40.4% men, and 1.1% nonbinary individuals. The mean age of participants was 46 years. Regarding ethnicity and race, 2.8% were Asian, 14.0% were Black, 12.5% were Hispanic, 66.5% were White, and 4.2% were another race. The mean irritability score among participants was 13.6 on a scale of 5 to 30.

The analysis considering sociodemographic characteristics revealed that a higher level of irritability is associated with female gender, younger age, lower educational background, lower family income, and being White.

Further analysis controlling for sociodemographic characteristics revealed that a higher level of irritability is associated with total depression and anxiety severities and risk of suicidal thoughts. The study employed network analysis, revealing a strong correlation was observed between irritability and suicidal thoughts in participants with moderate or major depression.

The highest effect of irritability on suicidal thoughts was observed among male participants and those aged 65 years and above.

A longitudinal analysis was conducted on individuals who participated in both waves of the survey. In this analysis, a total of 1979 individuals without suicidal thoughts on the initial survey wave were assessed for such thoughts on the subsequent survey wave.

The findings revealed that higher levels of irritability in the initial survey were significantly associated with a greater likelihood of suicidal thoughts in the subsequent survey. This indicates that irritability may precedes suicidal thoughts.    

Study significance

The study finds that irritability is a common feature among U.S. adults, which frequently but not invariably co-exist with major depressive or anxiety symptoms. The study also finds that higher levels of irritability can increase the risk of suicidal thoughts.

Among study participants without major depression or generalized anxiety, 1.8% reported high levels of irritability. Sociodemographic characteristics, including younger age, female gender, lower education, and lower income, are identified as significant predictors of high irritability, irrespective of the presence of major depression or generalized anxiety.

These findings highlight the need to examine the variation in prevalence and severity of neuropsychiatric characteristics across generalizable populations and not solely on individual diagnoses.

The network analysis conducted in the study further demonstrates that the correlation between irritability and suicidal thoughts is stronger in the presence of moderate or major depression. In contrast, the correlation between concentration and interest is less intense.

According to the study findings, irritability is most common among young individuals. However, the magnitude of the association between irritability and suicidal thoughts is much stronger among older adults. This highlights the importance of broadening the focus on irritability beyond adolescents to adults.

Overall, the study findings highlight the need for incorporating irritability measurement in clinical assessment of mood or anxiety disorders and developing therapeutic interventions to address and ameliorate this symptom.

As mentioned by the scientists, future studies should consider the impact of substance abuse or other psychiatric disorders (bipolar disorder) to understand the implications of irritability among adults more conclusively.

These surveys were conducted during the COVID-19 pandemic, a time when the prevalence of depressive symptoms was notably higher than usual. Thus, further studies are needed to determine whether these symptoms reflect broader stressors or specific national circumstances during this period.