Unraveling the Threads of Trepidation: The Prevalence and Evolving Contours of Anxiety and Traumatic Stress

SPECIAL REPORT: ANXIETY & STRESS DISORDERS

Anxiety and traumatic stress are as ancient as the human limbic system but have recently taken the public spotlight.¹ Clinician and public attunement to identification and treatment of anxiety disorders and posttraumatic stress disorder (PTSD) has increased, resulting in both increased clinician screening and patient self-diagnosis. Although rigorously obtained epidemiological data arguably do not reflect the perceived burden, estimates of anxiety disorders have increased over time. Anxiety disorders and PTSD are increased with environmental stressors such as COVID-19 and perceived global instability. Moreover, well-established risk factors such as gender, age, and comorbidities remain as relevant as ever. An understanding of evolving risk factors and pathophysiology is vital to optimal clinical management.

Shifting Categorizations
A separate focus on traumatic stress

Notably, there has been some change in the psychiatric lexicon over the past decade. Anxiety and traumatic stress overlap phenomenologically—both involve typically increased levels of arousal and impaired interpersonal and occupational functioning. Moreover, biologically, many of these features derive from a shared maladaptive limbic system, or autonomic outputs that produce amygdala activation and/or elevated sympathetic drive. They nonetheless differ in their causes, degree of neuroendocrine dysregulation, and presenting symptoms, such that in 2013, PTSD was moved from the DSM-IV “Anxiety Disorders” to a new DSM-5 “Trauma- and Stressor-Related Disorders” section.² Along with their chapter relocations, diagnostic criteria for PTSD symptom clusters and generalized anxiety disorder (GAD) symptoms were also revised.^3,4

Lifetime prevalence of anxiety disorders and PTSD

Accurate estimates of lifetime prevalence are complicated by heterogeneity of sampling methods and the potential for inaccurate retrospective recall by participants. A rigorous study published by Kessler et al based on the National Comorbidity Survey Replication in 2012 examined lifetime prevalence using DSM-IV criteria.⁵ Approximately one-third of the adult and adolescent population met criteria for any anxiety disorder. Within the DSM-IV framework, PTSD and GAD showed prevalence rates of approximately 8.0% and 6.2%, respectively. Past month overall prevalence measured by the National Survey on Drug Use and Health increased from 5.1% to 6.7% between 2008 and 2018, but notably increased from 8.0% to 14.7% in the same time period among 18- to 25-year-old participants.⁶ Curiously, some of the most prevalent anxiety disorders were social phobia and specific phobia, both affecting approximately one-eighth of the sample and likely less salient to clinicians due to their relatively lesser effects on global functioning. Although anxiety and traumatic stress disorders generally have onset postdevelopmentally, their median onset is fairly young, in the 20s and 30s, with PTSD often occurring somewhat earlier and many cases occurring in late adulthood.

A 2021 systematic review of studies of PTSD prevalence noted significant variability in estimates due to heterogeneity of study design and diagnostic criteria, as well as sample variation, depending on the subpopulation being studied. Citing the National Epidemiologic Survey on Alcohol and Related Conditions-III, authors estimated a general civilian population lifetime prevalence of approximately 6%, with higher rates observed in Native American (22.9%) and non-Hispanic White populations (11.7%). Lifetime prevalence in veterans ranged from 7.7% to 17.0%, and other vulnerable groups included emergency responders and individuals with histories of substance use. Lifetime prevalence can exceed point prevalence and annual incidence in PTSD, with delayed onset after the traumatic event and illness resolution both being common clinical elements.⁷

Epidemiological and mechanistic recognition of complex and developmental trauma

Recognized in the current ICD but not the DSM, complex PTSD (CPTSD) is becoming an important subject of study both in the United States and internationally. Unlike PTSD, CPTSD arises in response to either developmental or nonisolated, prolonged trauma exposure. Additional symptoms that are not inherent to PTSD include poor affect regulation, poor self-concept, and insecurity in relationships. Although nationally representative American epidemiological data for CPTSD are difficult to come by, international data derived from a recent Irish study showed a past month prevalence of CPTSD, with PTSD estimated at 5.0% and CPTSD at 7.7%.

CPTSD seems to be associated with greater comorbidities. A recent Irish study found that approximately 25% of participants with diagnosed PTSD had either depression or anxiety, whereas 67% of those with CPTSD had comorbid depression and 50% had comorbid GAD.⁸ It is long appreciated from human and laboratory animal research that developmental trauma leads to sustained hypothalamic-pituitary-adrenal axis alterations, increased sensitivity of serotonin receptors, and structural changes in the brain such as reduced hippocampal volume and altered regional responses to stress as assessed with functional MRI.⁹ Anticipated increased recognition of CPTSD will likely lead to greater use of trauma-oriented management strategies.

Evolving Risk Factors

Gender, age, and comorbid conditions

Discussion of risk factors for PTSD is long standing, with conventional understanding regarding sex differences being that although men may be more trauma exposed, women are more likely to develop PTSD. Some have explained this through differential qualities of trauma exposure between sexes or the role of gender-typical traits. One study from Switzerland found the likelihood of PTSD development after any exposure to be twice as high in women as in men, with sexual abuse being the most frequent to lead to future PTSD.¹⁰ In general, the probability of developing PTSD after any specific exposure did not vary based on sex, suggesting that the nature of exposure may be more significant than inborn sex differences.¹⁰ Bipolar disorder, alcohol use disorder, and separation anxiety disorder were considered to be significant risks for PTSD development. Notably, age of traumatic exposure or family history of mood, anxiety disorder, or PTSD were not predictive across all models. Nevertheless, the preeminent role of child abuse and neglect as a risk factor for PTSD, anxiety, and mood disorders is clear.^10,11 Overall, the clinical value of common demographic factors remains limited in explaining prevalence and assessing pretest probability.

COVID-19 as a biopsychosocial exacerbating factor

Insights regarding the long-term effects of COVID-19 on anxiety disorders are still developing, with relevant questions including direct, long-term neurotropic effects of infection with SARS-CoV-2; the effects of pandemic lockdowns; increased illness anxiety; and broader social changes. One study found 33% worsening of anxiety severity in prospective 1 year follow-up in youth with preexisting GAD who developed COVID-19 infection during the first years of the pandemic.¹² Genome-wide analyses have indicated genetic associations between anxiety phenotypes and COVID-19 outcomes, possibly indicating shared molecular mechanisms for resilience vs illness, with some genetic variants being able to predict decreased COVID-19 hospitalization in tandem with stress reactivity in human and animal subjects.¹³ It is difficult to assess the exact relative contributions of direct biological effects, increased illness anxiety, and social fragmentation to worsening anxiety, but time will tell how the epidemiology has changed.

Youth anxiety regarding climate change

In a period of perceived concomitant crises, climate anxiety likely affects the youth. Across a survey of adolescents and young adults in 10 countries, approximately 60% stated that they were very or extremely worried, with 45% stating that their feelings about climate change negatively affect their daily life and functioning, and greater than 75% endorsing negative cognitions about climate futures for themselves and their communities. Climate anxiety was also related to perceptions of inadequate trust and care from the community government.¹⁴

Patterns in Diagnosis and Treatment

Increased screening

Efforts to improve preventive medicine leverage greater availability of quantitative measures and documentation. Screening for mental health disorders has been no exception. In 2023, the US Preventive Services Task Force extended anxiety screening from children and adolescents between ages 7 and 18 years to include adults up to age 64.¹⁵ Although adoption of these recommendations may identify cases, there may be downsides. Common instruments like the GAD-7 or GAD-2 are sensitive but nonspecific for GAD and may result in inadequately resourced providers using them to assess complex and heterogeneous psychiatric presentations, including PTSD with its significant symptom overlap.¹⁶ Screening instruments may also be sensitive to transient stressors and lead to unnecessary examination, diagnosis, and treatment in otherwise healthy individuals. Recommendations for screening must be balanced against a realistic view of available mental health services for patients.

Increased self-diagnosis

Another important phenomenon in clinical practice is self-diagnosis. Patients commonly face difficulties with self-stigma and access to care, which may lead to less-reliable methods for self-diagnosis. Although online resources may increase therapeutic engagement, there is risk for the development of a medically ungrounded parallel dialogue through social media and online communities. Social media platforms such as TikTok have been shown to increase self-diagnosis with several salient disorders, such as attention-deficit/hyperactivity disorder and Tourette syndrome, as well as to create expectations around response to antidepressants and increase diagnostic identification with diagnosed peers. There is also potential for inappropriate pathologizing of transient phenomena or even inappropriate self-medication through online pharmacies.¹⁷

Concluding Thoughts

Anxiety and PTSD are highly prevalent disorders that commonly present to primary care and mental health clinicians. They represent maladaptive variations of physiologic responses to phenomena of stress induced by the world. Fundamentals of good clinical practice can endure despite the shifts in our clinical understanding, illness-modifying exposures, and patient-clinician-illness relationships. Navigating appropriate expectations while sharing decision-making, conducting psychoeducation, and being discerning in diagnosis and treatment are essential to maintaining an effective alliance with the patient, preventing pathologizing, and maintaining a focus on resilience and recovery.

Dr Shapira is a first-year resident psychiatrist in the Department of Psychiatry and Behavioral Sciences at Dell Medical School in Austin, Texas. Dr Nemeroff is Matthew P. Nemeroff Endowed Chair and professor in the Department of Psychiatry and Behavioral Sciences at Dell Medical School in Austin, Texas. He is also the director of the Institute for Early Life Adversity Research and codirector of the Center for Psychedelic Research and Therapy.

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