Highlights
• Anxiety increased from 2008 to 2018 among American adults
• Nearly 7% of adults and 15% of young adults reported anxiety in 2018
• Anxiety increased most rapidly among young adults ages 18-25 years old
• Anxiety did not significantly increase among individuals 50 years old and older
Abstract
Introduction In a time of global uncertainty, understanding the psychological health of the American public is imperative. There are no current data on anxiety trends among adults in the United States (US) over time. This study aimed to investigate prevalence of anxiety among US adults from 2008-2018.
Methods Data from the National Survey on Drug Use and Health (NSDUH), which is an annual, cross-sectional survey on substance use and mental health in the US, were analyzed in 2020. Prevalence of past-month anxiety was estimated among those ages ≥18, by survey year from 2008 to 2018. Time trends were tested using logistic regression.
Results Anxiety increased from 5.12% in 2008 to 6.68% in 2018 (p<.0001) among adult Americans. Stratification by age revealed the most notable increase from 7.97% to 14.66% among respondents 18-25 years old (p<.001), which was a more rapid increase than among 26-34 and 35-49 year olds (differential time trend p<.001). Anxiety did not significantly increase among those ages 50 and older. Anxiety increased more rapidly among those never married and with some college education, relative to their respective counterparts. Apart from age, marital status and education, anxiety increased consistently among sociodemographic groups.
Conclusions Anxiety is increasing among adults under age 50 in the US, with more rapid increase among young adults. To prepare for a healthier adulthood and given direct and indirect (via 24/7 media) exposure to anxiety-provoking world events, prophylactic measures that can bolster healthy coping responses and/or treatment seeking seem warranted on a broad scale.
Keywords: anxietynervousnessmental healthepidemiologyNSDUH
DISCUSSION
Overall, our results are consistent with and extend prior findings that mental health has worsened in the US by showing that anxiety, too, has broadly increased among adults in the US over the past decade. Anxiety appears most common among young adults and has increased more rapidly among 18 to 25-year-olds than among any other age group. Anxiety also increased more rapidly among those never married versus married and among those with a high school diploma or some college versus those who did not complete high school. Anxiety increased consistently across racial/ethnic, gender and income subgroups. Adults over age 50 was the only demographic subgroup amongst whom anxiety did not change from 2008 to 2018.
The overall increase in anxiety in the US population was broad and consistent across sociodemographic groups, suggesting that large-scale public health approaches to mitigate anxiety may be needed, in addition to outreach and increasing accessibility of mental health services. In terms of education, the increase in anxiety was slower among those who did not complete high school vs. those with higher formal education. Of all subgroups, unmarried adults and young adults showed the most rapid increases in anxiety. Being married has been consistently associated with health benefits (Curtin and Tejada-Vera, 2019; Kaplan and Kronick, 2006; Rendall et al., 2011). These findings may relate to many factors including differences in social isolation, social support and financial stability (Cacioppo et al. 2014; Holt-Lunstad et al. 2015; Petitte et al. 2015). Some data suggest a link between loneliness and anxiety (Igbokwe et al., 2020), though there is little research on the relationship between social isolation and anxiety. Especially considering extended social isolation across the world due to the COVID-19 pandemic, this is an issue that may gain even more salience in protecting the mental health of the country (Elran-Barak and Mozeikov, 2020).
Anxiety is most common and has increased most rapidly among young adults. Anxious temperament and subclinical anxiety earlier in life is associated with increased risk of subsequent onset of anxiety disorders, depression, substance use disorders and physical health problems (e.g., Bittner et al., 2004; Goodwin, 2002; Goodwin et al., 2004a, b; Olafiranye et al., 2011; Ringbäck Weitoft and Rosén, 2005; Roy-Byrne et al., 2008; Taha et al., 2014; Wittchen et al., 2003). Young adulthood is the key period of vulnerability for the onset of these conditions. Therefore, increasing anxiety in this vulnerable group would be expected to have a greater impact on longer-term mental health and functional outcomes than increases in anxiety in older age groups. In addition, anxiety or stress has been shown to influence brain development, which is not completed until approximately age 25 (e.g., McEwen, 2011; Piccolo and Noble, 2018; Saleh et al., 2017). Increased persistent anxiety among young adults therefore could have long-term impact on academic, psychological and social development. Further, the explosion of social media, which is associated with increased anxiety and depression among young people, may be a contributing factor to the increase in anxiety over time, especially after 2011 (Barthorpe et al., 2020; Hollis et al., 2020; Riehm et al., 2019).
On a population level, our findings are consistent with recent data from Sweden reporting that adults, and young adults in particular, experienced an increase in poor sleep, stress and poorer general health from 2000 to 2016 (Blom et al., 2020). Data from US adults also suggest increased levels of stress, with work and money articulated as the most common reasons for anxiety (American Psychological Association, 2014, 2016). The time frame of the current study included the 2016 presidential election, which was reported by more than half of US adults, including more than half of Millennials (ages 20 to 35), as a significant source of stress (American Psychological Association, 2017; Hoyt et al., 2018; Zeiders et al., 2019). No direct relationship between specific events and changes in anxiety can be drawn from this study. Therefore, similar to findings regarding increases in mental health problems and the 2008 financial crisis (e.g., Case and Deaton, 2015), any connection between changes in anxiety and the effect of national events on a population level would be speculative but may be important to consider in individual-level clinical efforts to address and reduce anxiety. Such relationships may be worthy of consideration in both public health and clinical planning to address the increasing anxiety that appears widespread in the US, especially among young adults. Young people are confronting more potentially anxiety-provoking world events than prior generations, and exposure to such events is now pervasive with access to 24/7 media.
While symptoms of anxiety are associated with increased likelihood of subsequent anxiety disorders and depression, treatment for subclinical anxiety has also been shown to reduce the risk of these outcomes (Goodwin and Gorman, 2002; Goodwin and Olfson, 2001). The assessment of anxiety in the current study (self-reported nervousness) is not diagnostic of either subclinical or clinical anxiety, but the finding that over 40% of those classified as having anxiety in these analyses (i.e., those reporting nervousness most or all of the time) reported past-year treatment suggests that their anxiety was related to distress or impairment, given that a minority of individuals with anxiety are seen for treatment in the US. Treatment for anxiety is delayed in the vast majority of cases (Iza et al., 2013; Kessler et al., 1998), and most anxiety symptoms or disorders go untreated due to various issues including, but not limited to, lack of awareness of symptoms and effectiveness of treatment, stigma, and lack of parity in mental health coverage (Christiana et al., 2000; Wang et al., 2004).
Limitations
Limitations of this study must be considered when interpreting these results. First, although technically synonymous with “anxiety,” “nervousness” is one expression of anxiety and neither encompasses all types of anxiety nor is reflective of a clinically diagnosed anxiety disorder. Yet, in light of the fact that a substantial percentage of respondents with anxiety reported seeking mental health treatment—on par with those with mental health problems who receive specialized treatment—supports the likelihood that this variable is capturing clinically significant anxiety (Olfson et al., 2019). There is a relative paucity of anxiety measures in national surveys assessed consistently over time. To our knowledge, this is the only measure that could be considered an indicator of anxiety that has been assessed consistently over the past decade in a nationally representative sample. Second, it is possible that the increase observed is due to differences in reporting related to decreasing stigma associated with mental disorders. However, it seems less likely that differences in age groups and other sociodemographics would be observed were that the case, and the fact that “nervousness” is not a disorder seems to reduce the likelihood that this is the sole reason for this finding, though it is possible. Third, NSDUH data are repeated cross-sectional samples and longitudinal data would be important for examining changes in anxiety, changes in variables potentially associated with anxiety, and the timing of changes in anxiety and associated variables among individuals. Finally, while this study was designed to examine sociodemographic differences in anxiety over time, there may be other variables associated with anxiety that may be useful to identify vulnerable subgroups.