Evolution of Treatment Modalities for Posttraumatic Stress Disorder: Top 100 Cited Articles From 1990 to 2020

Bibliometrics is a quantitative research methodology used to evaluate research productivity in a given subject area within a field over time.¹ It is an important mapping tool to establish research priorities and direct the allocation of funds by charting the emerging trends in science and technology. Moreover, bibliometric analysis can be utilized to acknowledge the major contributors in academia, whether they are authors, journals, institutions, or countries.²

Trauma is an event that exposes a person to the danger of death, physical injury, or sexual violence.^3,4 Posttraumatic stress disorder (PTSD) is defined as the cluster of symptoms caused by “somatic, cognitive, affective, and behavioral effects of trauma.”^5(p83-93) One of every 3 young people experiences trauma, and of the exposed populace, every fourth child develops PTSD by the age of 18 years.⁴ In 2017, a World Health Organization survey yielded a PTSD prevalence of 5.0% in the general population of high-income countries, 2.3% in upper-middle–income countries, and 2.1% in lower middle–income countries, respectively.⁶ Moreover, the 2019 Global Burden of Disease report revealed an alarming number of 316 million adult war survivors suffering from PTSD and/or mental disorders worldwide, leading to 3 million disability-adjusted life years.⁷ Also, the prevalence of PTSD in medical practitioners has been on a continuous rise since the onset of the COVID-19 pandemic; 25.4% of health care workers in the National Health Service screened positive for PTSD in 2021 by DSM-5 criteria.⁸ If not treated in a timely manner, PTSD is said to contribute to increased suicide rates in 53.9% of females and 67.2% of males.⁹

Owing to the subjectively varied responses of PTSD patients to their triggers, diagnosing and treating PTSD has always posed a challenge to mental health experts.¹⁰ Factors such as avoidance, social stigma, limited resources, ongoing conflicts, and wars make it difficult for trauma survivors to seek early professional help and compromise the efficacy of available treatment options.¹¹ The last couple of decades have seen significant progress in terms of PTSD research.¹² However, there has been no quantitative charting of the evolution in evidence-based treatment modalities of PTSD in terms of improved outcomes. The objective of this study was to conduct a bibliometric analysis to bridge this gap in knowledge and aid the scientific community in determining future directions for PTSD treatment.

METHODS

The database Scopus was used for the bibliometric analysis. Regarding scientific publications, the available evidence and analysis suggest that Scopus has a wider scope than other databases such as PubMed and Web of Science.^13,14 We selected 2 reviewers (M.T. and B.N.) to search the Scopus database in November 2022. The first list contained original research articles, which were segregated from review articles by Scopus filters. To yield the maximum number of articles in the analysis, the research studies on nonhuman subjects, those without abstract availability, and those in languages other than English were also included. The articles published from 1990 to 2020 were included irrespective of their publication journal. The following search term was used for retrieving articles from Scopus: “(TITLE-ABS KEY(((posttraumatic stress disorder) OR PTSD OR (traumatic stress disorders) OR (trauma-related disorders) OR (complex trauma)) AND ((treatment modalities) OR management OR therapeutics OR (treatment outcomes) OR (interventions integrated treatment) OR psychotherapy OR (pharmacological therapy) OR (drug therapy) OR psychedelics OR (diet therapy) OR (physical therapy) OR (exposure therapy) OR (neuromodulation therapy) OR (combined therapy) OR (accelerated resolution therapy) OR (eye movement desensitization and reprocessing) OR (cognitive behavioral therapy) OR (Stellate Ganglion Block)))).”

The selected studies primarily focused on the treatment modalities of PTSD. The appropriateness and relevance of the articles with the inclusion criteria were determined by thoroughly reviewing the abstracts. In case the abstracts were unavailable in Scopus, other sources were utilized to extract the abstracts and assess their suitability. The “cited by” filter was used to gather and organize the yielded articles. The most-cited 100 articles were thus compiled in the final list. Only those articles to which both reviewers agreed based on the inclusion criteria were included in the final list.

The analysis of the final list of articles was carried out using Scopus and manual screening. The total number of citations and number of citations per year were analyzed in terms of mean, median, and interquartile range (IQR). The Thomson Reuters journal citation reports were used to obtain the impact factors of the journals. Appropriate tables and graphs were generated using Microsoft Excel version 2016. SPSS version 26 was used to determine the correlation between the journal’s impact factor and its representation regarding the number of articles in the 100 most-cited articles. We considered a P value <.05 as significant. The subsequent search was conducted in the same manner to obtain the second list of most-cited review articles on the treatment modalities of PTSD.

RESULTS

Citation Count, Citations Per Year, and Citation Trends

Table 1 shows total citations and citations per year for the top 100 most-cited articles from 1990 to 2020. The number of citations was a minimum of 215 and a maximum of 1,056, with a median of 282 and an IQR of 139. The number of citations for all the articles was summed to a total of 35,549.

The number of citations per year ranged between 7.03 and 46.5, with a mean of 20.3009, median of 17.49, and IQR of 11.215. Also, if we look at the 10 most-cited research articles in this field since 2021 as of this writing, as these are the articles that are driving research, driving research, interesting trends towards research in newer treatments such as MDMA and ketamine in the form of robust clinical trials are revealed (Table 2).Figure 1 shows the total citations of the articles per year. The analysis revealed an exponential increase in the number of citations per year, with the most notable increase occurring between 2010 and 2012 and the peak citations per year being in 2012. After 2012, there was a smaller but almost similar number of citations per year up to 2016. After 2016, the trend decreased during the next few years.

Figure 2 shows the 5-year average citations. Our analysis revealed that the average increased exponentially over the 5-year intervals. Although during the 5 years between 2009 and 2013 the average citations were notably higher than the previous intervals, the most citations per 5 years were within the years 2014 and 2018. However, the average 5-year citations notably went down between the years 2019 and 2022 compared to the previous years.

Year of Publication, Origin, and Authorship

The 100 most-cited articles regarding evolution in therapeutic modalities for PTSD were published between 1990 and 2015. These articles originated from 15 different countries, with 2 being unidentified countries of origin. More than half of these articles originated from the United States (77 articles), followed by the United Kingdom (8 articles) and Germany (7 articles) (Figure 3).

The total number of authors involved in the publication of these articles is 641, with a median of 6 authors per article (IQR = 4). The number of authors in the 100 most-cited articles included in the study ranges from 1 to 21. The authors with 5 or more articles among the most-cited articles are listed in Table 3, which shows that most of these articles included in the study were coauthored by E.B. Foa (11 articles). Table 3 also shows the authors’ H index, which demonstrates the overall impact of the authors as measured by the author-specific citation frequency.

Further, if we analyze the trends of the number of articles published during the specified period (1990-2020) and plot against the year of publication, the year 2003 was the most productive year in terms of academic outcome, with 10 publications in that year (Figure 4). Table 4 shows the journals and respective number of published articles during the study period.

DISCUSSION

We provide a bibliometric analysis of the most-cited articles on PTSD to highlight significant developments in its understanding and management. This analysis can highlight critical areas in PTSD, both where research is ongoing and where it might be conducted in the future, which can be of great use to physicians and researchers. It can also aid in the development of collaboration among researchers from many disciplines, enabling them to investigate PTSD research further.

We observed a gradual increase in the number of articles published in the last 2 decades, with the maximum research productivity seen in 2003 and 2007 with 10 and 7 articles, respectively. The leading causes of the gradual increase may be the increasing trend in the prevalence of PTSD over the last decade, as well as the increasing rates of suicide and the everyday difficulties faced by military personnel who have this diagnosis.¹²⁵ Over the years, these projects, funded mainly by US government agencies, have contributed to our improved understanding of the brain, human behavior, the consequences of chronic stress on the hypothalamic-pituitary-adrenal axis system, and improved treatment approaches. Still, the scholarly output on PTSD seems to be rising slowly compared to that on other psychiatric illnesses such as schizophrenia,¹²⁶ bipolar disorder,¹²⁷ and depression.¹²⁸

We chose citations per year as a more trustworthy metric to determine an article’s current influence because citation count alone is not an accurate indicator of an article’s scientific value.¹²⁹ When articles were arranged according to citations per year, the most-cited article was by Resick et al (2002).¹⁷ However, the article with the maximum number of citations was a relatively older article (1991) by Foa et al.¹⁵ This result confirms that, even if an article’s impact is greater than that of an older article, it is likely to rank lower when evaluated only based on its citation count, as newly published articles take time to generate citation count. The author with the maximum number of articles among the top 100 was a female senior researcher, E.B. Foa, while 5 of 6 top performing authors were also female. This is a quite promising finding that female researchers have outpaced their male colleagues in research on PTSD. Still, we cannot negate the traditional gender disparity found in psychiatry¹³⁰ and other fields of medicine,^131–133 with only 42% of female psychiatrists in the United States.

About three-fourths of the scholarly output came from the United States, followed by the United Kingdom and Germany. Moreover, 5 of 6 authors and institutes with maximum research output were also from the United States. This trend aligns with many other studies conducted in various research fields.^{126,128,134–137} This trend has several causes, the most significant of which is the financial support any nation provides. The US government, private sector organizations, and foundations such as the National Institutes of Health and National Science Foundation invest heavily in research and development. A robust higher education system, an elaborate collaborative network, a research infrastructure, and a competitive peer-review process contribute as well.¹³⁸ Although the burden of PTSD in low- and middle-income countries is high,¹³⁹ not even a single country with low resources was the primary contributor or leader of these highly impactful studies.¹⁴⁰ The lack of high-impact studies in low- and middle-income countries is attributable to limited human development and expenditure in education and scientific research, limited access to technology and quality education, language barriers, political and social instability, and limited collaboration opportunities.¹⁴¹ Also, prioritizing basic needs such as health care, nutrition, and sanitation over research is common in low-income countries. Therefore, it highlights the importance of developing a comprehensive health financing policy for these countries, allocating at least 15% of the national budget to health development.^142,143 The journal that published the maximum number of articles was the Journal of Consulting and Clinical Psychology (25 articles), while the journal with the maximum impact factor was the American Journal of Psychiatry (17.7 in 2022). This pattern suggests that a journal’s relevance to the subject matter is more important than its impact factor.

Our results have some limitations. First, some articles might be missed, as only the Scopus database was utilized. Articles published before the 1980s, when a computerized system was put in place, are frequently overlooked by Scopus.¹⁴⁴ Second, self-citations were not removed. Third, most articles were published in English, which could result in bias in the publishing language selection process. Interestingly, the publication of newer editions of the DSM often coincides with a surge in research in the relevant areas, as researchers and clinicians try to adapt to newer diagnostic criteria and explore their use. Futher analyses and research might investigate how these updates correlate with the trends in clinical practice.

CONCLUSION

The observed decline in citations in recent years may suggest a redirection of focus toward alternative areas of interest. Furthermore, the data indicate that most reviewed publications were produced in economically affluent nations, underscoring the importance of facilitating research specifically tailored to the unique contexts of emerging and underdeveloped regions.

Article Information

Published Online: December 12, 2024. https://doi.org/10.4088/PCC.24nr03767
© 2024 Physicians Postgraduate Press, Inc.
Submitted: May 11, 2024; accepted August 20, 2024.
To Cite: Ali M, Naseer B, Siddal MT, et al. Evolution of treatment modalities for posttraumatic stress disorder: top 100 cited articles from 1990 to 2020. Prim Care Companion CNS Disord. 2024;26(6):24nr03767.
Author Affiliations: King Edward Medical University, Lahore, Pakistan (Ali, Naseer, Ahmed); Shaikh Khalifa Bin Zayed Al Nahyan Medical and Dental College, Lahore, Pakistan (Siddal); CMH Medical College, Lahore, Pakistan (Talha); Jinnah Sindh Medical University, Karachi, Pakistan (Jabeen); Sargodha Medical College, Sargodha, Pakistan (Mehmood); Dow University of Health Sciences, Karachi, Pakistan (Hashmi); University of Nevada, Las Vegas, Nevada (Shad).
Corresponding Author: Mohsan Ali, MBBS, King Edward Medical University, Neelagumbad, Anarkali, Lahore 54000, Pakistan ([email protected]).
Relevant Financial Relationships: None.
Funding/Support: None.

Clinical Points

• The increased research output following the DSM updates suggests that clinicians should stay informed about DSM changes, as they may drive significant advancements in understanding and treating posttraumatic stress disorder (PTSD).
• A substantial portion of PTSD research and its clinical applications originate in the United States, highlighting the need for international collaboration to address PTSD in diverse populations effectively.
• Barriers to high-impact PTSD research in low- and middle income countries include limited resources and funding, emphasizing the importance of developing comprehensive health financing policies to improve PTSD treatment outcomes globally.