Phytotherapy and psychiatry: bibliometric study of the scientific literature from the last 20 years

Trends in the St. John's wort (Hypericum perforatum) research literature: a bibliometric analysis

OBJECTIVES

St. John's wort (Hypericum perforatum) has been used in traditional medicine for centuries for different conditions, including kidney and lung ailments, insomnia, depression, and to aid wound healing. The objective of the present bibliometric analysis is to capture the characteristics of research publications on the topic of St. John's wort.

METHODS

Searches were run on April 09, 2021, and results were exported on the same day to prevent discrepancies between daily database updates. Trends associated with this subset of publications were identified and presented. Bibliometric networks were constructed and visualized using the software tool VOSviewer.

RESULTS

A total of 1,970 publications were published by 5,849 authors across 961 journals from 1859 to 2021. Beginning in the late 1990s, a steep increase was found in the volume of publication on this topic. The journal that published the largest number of publications was Phytotherapy Research. The most productive countries included Germany and the United States.

CONCLUSIONS

The present study provides the characteristics of the St. John's wort literature that allows understanding of the past, present, and future of research in this area. It is a useful evidence-based framework on which to base future research actions and academic directions.

A Bibliometric and Mapping Analysis of Glaucoma Research between 1900 and 2019

PURPOSE

To explore the relevance of scientific production on glaucoma using bibliometric tools.

DESIGN

Bibliographic study.

PARTICIPANTS

Original articles published from 1900 through 2019.

METHODS

We performed a search in Web of Science for documents published between 1900 and 2019. We used bibliometric indicators to explore documents production, dispersion, distribution, time of duplication, and annual growth, as characterized by Price's law of scientific literature growth, Lotka's law, the transient index, and the Bradford model. We also calculated the participation index of different countries and institutions. Finally, we explored with bibliometric mapping the co-occurrence networks for the most frequently used terms in glaucoma research.

MAIN OUTCOME MEASURES

Bibliometric indicators for individuals, institutions, and countries.

RESULTS

A total of 33 631 original articles were collected from the timeframe 1900 through 2019. Price's law showed an exponential growth. Scientific production was adjusted better to exponential growth (r = 0.967) than linear growth (r = 0.755). Literature on glaucoma research increased its growth in the last 30 years at a rate of 5.1% per year with a production that doubled its size every 13.9 years. The transience index was 60.08%; this indicates that most of the scientific production is the output of very few authors. Bradford's law showed a high concentration of articles published in a small core of specialized journals. Lotka's law indicated that the distribution of authors is concentrated heavily in small producers. The United States and University of London demonstrated the highest production of original articles. Map network visualization showed the generated term map detailing clusters of closely related terms.

CONCLUSIONS

Glaucoma literature has grown exponentially. A very high rate of transience was found that indicates the presence of numerous authors who sporadically publish on this topic. No evidence of a saturation point in the glaucoma literature was observed.

Worldwide Research on Land Use and Land Cover in the Amazon Region

Land cover is an important descriptor of the earth’s terrestrial surface. It is also crucial to determine the biophysical processes in global environmental change. Land-use change showcases the management of the land while revealing what motivated the alteration of the land cover. The type of land use can represent local economic and social benefits, framed towards regional sustainable development. The Amazon stands out for being the largest tropical forest globally, with the most extraordinary biodiversity, and plays an essential role in climate regulation. The present work proposes to carry out a bibliometric analysis of 1590 articles indexed in the Scopus database. It uses both Microsoft Excel and VOSviewer software for the evaluation of author keywords, authors, and countries. The method encompasses (i) search criteria, (ii) search and document compilation, (iii) software selection and data extraction, and (iv) data analysis. The results classify the main research fields into nine main topics with increasing relevance: ‘Amazon’, ‘deforestation’, ‘remote sensing’, ‘land use and land cover change’, and ‘land use’. In conclusion, the cocitation authors’ network reveals the development of such areas and the interest they present due to their worldwide importance.

Effects of Passiflora incarnata Linnaeus on polysomnographic sleep parameters in subjects with insomnia disorder: a double-blind randomized placebo-controlled study

The purpose of the present double-blind randomized placebo-controlled clinical study was to investigate the effects of Passionflower on polysomnographic sleep parameters in subjects with insomnia disorder. A total number 110 adult participants (mean age = 40.47 ± 11.68, Female = 53.6%) met the inclusion criteria of insomnia disorder according to the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders). After randomization, patients received either the Passionflower extract or the placebo for 2 weeks. Patients underwent an overnight polysomnography and completed sleep diaries, Insomnia Severity Index, and Pittsburgh Sleep Quality Index. Within group comparisons were analyzed with paired t-tests or Wilcoxon's signed rank tests, and between-group comparisons were analyzed with independent t-tests or Mann-Whitney U Tests, as appropriate. Total sleep time (TST) was significantly increased in the Passionflower group compared with placebo (Passionflower vs placebo, 23.05 ± 54.26 vs -0.16 ± 53.12; P = 0.049). Sleep efficiency and wake after sleep onset (WASO) significantly improved after 2 weeks in the Passionflower group but there was no difference compared with the placebo group. The current study demonstrated the positive effects of Passionflower on objective sleep parameters including TST on polysomnography in adults with insomnia disorder. Further study is needed to investigate the clinical efficacy of Passionflower on insomnia.

Complementary and Alternative Medicine Treatments for Generalized Anxiety Disorder: Systematic Review and Meta-analysis of Randomized Controlled Trials

INTRODUCTION

The objective was to evaluate efficacy/safety of complementary and alternative medicine (CAM) methods for generalized anxiety disorder (GAD) based on randomized controlled trials in adults.

METHODS

Data sources. Six electronic databases ("generalized anxiety (disorder)" and "randomized trial") and reference lists of identified publications were searched to March 2017.

STUDY SELECTION

Eligibility: full-text publications (English, German language); CAM versus conventional treatment, placebo/sham or no treatment; GAD diagnosed according to standard criteria; and a validated scale for disease severity. Of the 6693 screened records, 32 were included (18 on biologically-based therapies, exclusively herbal preparations; eight on manipulative and body-based therapies; and three on alternative medical systems and three on mind-body therapies).

DATA EXTRACTION

Cochrane Collaboration methodology was used for quality assessment and data extraction.

RESULTS

Direct comparisons of Kava Kava (Piper methysticum) extracts to placebo (4 quality trials, n = 233) were highly heterogeneous. Network meta-regression reduced heterogeneity and suggested a modest Kava effect [end-of-treatment Hamilton Anxiety scale score difference adjusted for baseline scores and trial duration: - 3.24 (95% CI - 6.65, 0.17; P = 0.059), Kava Kava 4 arms, n = 139; placebo 5 arms, n = 359]. Lavender (Lavandula angustifolia) extract (1 quality trial, 10 weeks, n = 523) and a combination of extracts of C. oxycantha, E. californica and magnesium (1 quality trial, 12 weeks, n = 264) were superior to placebo and balneotherapy was superior to paroxetine (1 quality trial, 8 weeks, n = 237) indicating efficacy. All other trials were small and/or of modest/low quality and/or lacked assay sensitivity. Safety reporting was poor.

CONCLUSION

Evidence about efficacy/safety of most CAM methods in GAD is limited. Apparent efficacy of certain herbal preparations and body-based therapies requires further confirmation.

Ethnobotany and herbal medicine in modern complementary and alternative medicine: An overview of publications in the field of I&C medicine 2001-2013

ETHNOPHARMACOLOGICAL RELEVANCE

Ethnobotanical knowledge and traditional medicinal practices from different parts of the world are of global importance and documentation of ethnobotanical, and ethnopharmacological data is a key prerequisite for further research in the area of herbal medicine and its implementation in clinical practice.

AIMS

An attempt was made to evaluate the scientific output of research related to ethnobotany and herbal medicine in journals indexed in the subject area "Integrative and Complementary Medicine" in the period 2001-2013, in order to ascertain research trends in both subdisciplines.

MATERIALS AND METHODS

All articles related to ethnobotany and herbal medicine, extracted from journals included in the field of I&C Medicine and published in the period 2001-2013, have been analyzed for general bibliometric data, and specific data: ethnobotanical data (geographic, floristic, pharmacological, sociological and other relevant data) and phytotherapeutic data (type of applied herbal medicine, plant species studied, pharmacological activity of studied plant species and disease and disorder type studied on a particular model).

RESULTS

In the studied period, the number of articles dealing with ethnobotany and herbal medicine increased 6.3-fold. Articles related to ethnobotanical studies documented medicinal flora from 81 countries, either giving an overview of overall medicinal flora, or presenting the ethnomedicinal aspect of the use of plants for the treatment of ailments typical to the studied area. Additionally, the authors provided significant information on the methods of use and herbal preparations. In herbal medicine studies, plants, traditional plant remedies, herbal medicinal products and active herbal compounds were tested for many of pharmacological activities (146), with the curative activity emerging as most frequently tested. Out of 39 model systems, most of the studies were carried out under controlled in vitro conditions (4589 articles), followed by rat in vivo (2320), human in vivo (1285), mouse in vivo (955), and on agents of pathogenic diseases (887); more than 800 medical disorders were treated.

CONCLUSIONS

The study revealed the regions most studied for new records of floristic and ethnomedicinal diversity, the most frequently studied plant species, and the most promising therapeutic indications for the integration of herbal remedies in the curative process, as ascertained from the selected bibliographic databases.

International comparative performance of mental health research, 1980-2011

Scientific understanding of mental illness, mental health and their neurobiological and psychosocial underpinnings has greatly increased in the last three decades. Yet, little is known about the landscape of this knowledge and how and where it is evolving. This paper provides a bibliometric assessment of mental health research (MHR) outputs from 1980 to 2011. MHR papers were retrieved using three strategies: from key mental health journals; using US National Library of Medicine Medical Subject Heading (MeSH) keywords; and from additional journals in which mental health topics accounted for over 75% of papers. The number of papers per year increased over time in absolute terms and as a proportion of total medical output. The US's proportion of world publication output dropped from 60% in 1980 to 42% in 2011, while the EU increased its share from 27% to 40%. Countries with greater research intensity in mental health generally had higher citation impact, such as the US, UK, Canada and the Netherlands. MHR also became more collaborative: 3% of all MHR papers published in 1980 were the result of international collaboration compared to 22% in 2011. We conclude by noting that the rise in MHR appears to be due to funding and that bibliometrics can help highlight the potential drivers of variation in performance of MHR systems. The paper provides an analytical basis for benchmarking MHR trends in the future.

Current challenges in appraising complementary medicine evidence

Increased research in the area of complementary and alternative medicine (CAM) is urgently required, in addition to a balanced appraisal and communication of the state of evidence in the field. Current challenges for clinicians and the public in accepting purported CAM evidence concern potential selective publication of results, marked differences in product quality and standardisation, and some companies making unsubstantiated claims. To improve confidence in the industry, companies must publish all results and only make substantiated claims. In addition, providing intellectual property protection to CAM companies may encourage greater investment in research; however, more accountability of study results is critical.

Trend in dental research output in Iran over a period of 20 years (1990-2009)

INTRODUCTION

The number of scientific papers is a conventional metric for the measurement of a country's research performance in a particular area.

OBJECTIVE

To evaluate the trend in Iranian publications of dental research results in peer-reviewed international scientific journals over the period 1999-2009, using national and international databases, and to compare the results with other countries.

METHODS

The search process was performed by two independent persons in PubMed and Iranian Medline (IranMedex). Data extraction included the year of publication, total number of dental papers in each year, total number of Iranian dental papers in each year and number of papers with a high level of evidence; these were compared with those in other Asian countries.

RESULTS

The total number of dental articles indexed in PubMed during the studied period was 207,689, with 671 being written by researchers who stated their affiliation as Iran. Although the proportion of Iranian dental articles to all published dental articles was 0.01% in 1990, this increased to 1.4% in 2009. Of all clinical trials indexed in PubMed from 1990 to 2009, only 0.62% had an author from Iran. The collaboration rate of authors ranged between 1 and 10. Turkey and Iran had a larger number of dental research publications compared with other Asian countries assessed in this study.

CONCLUSION

During the last two decades, there has been a considerable increase in the number of dental papers by Iranian researchers indexed in the PubMed database.

Herbal medicine for depression, anxiety and insomnia: a review of psychopharmacology and clinical evidence

Research in the area of herbal psychopharmacology has increased markedly over the past decades. To date however, a comprehensive review of herbal antidepressant, anxiolytic and hypnotic psychopharmacology and applications in depression, anxiety and insomnia has been absent. A search of MEDLINE (PubMed), CINAHL, PsycINFO, and the Cochrane Library databases was conducted (up to February 21st 2011) on commonly used psychotropic herbal medicines. A review of the literature was conducted to ascertain mechanisms of action of these botanicals, in addition to a systematic review of controlled clinical trials for treatment of mood, anxiety and sleep disorders, which are common comorbid psychiatric disorders. Specific emphasis was given to emerging phytomedicines. Analysis of evidence levels was conducted, as were effect sizes (Cohen's d) where data were available. Results provided evidence of a range of neurochemical, endocrinological, and epigenetic effects for 21 individual phytomedicines, which are detailed in this paper. Sixty six controlled studies were located involving eleven phytomedicines. Several of these provide a high level of evidence, such as Hypericum perforatum for major depression, and Piper methysticum for anxiety disorders. Several human clinical trials provide preliminary positive evidence of antidepressant effects (Echium amoenum, Crocus sativus, and Rhodiola rosea) and anxiolytic activity (Matricaria recutita, Ginkgo biloba, Passiflora incanata, E. amoenum, and Scutellaria lateriflora). Caution should however be taken when interpreting the results as many studies have not been replicated. Several herbal medicines with in vitro and in vivo evidence are currently unexplored in human studies, and along with use of emerging genetic technologies "herbomics", are areas of potential future research.

Nutritional and herbal supplements for anxiety and anxiety-related disorders: systematic review

BACKGROUND

Over the past several decades, complementary and alternative medications have increasingly become a part of everyday treatment. With the rising cost of prescription medications and their production of unwanted side effects, patients are exploring herbal and other natural remedies for the management and treatment of psychological conditions. Psychological disorders are one of the most frequent conditions seen by clinicians, and often require a long-term regimen of prescription medications. Approximately 6.8 million Americans suffer from generalized anxiety disorder. Many also suffer from the spectrum of behavioural and physical side effects that often accompany its treatment. It is not surprising that there is universal interest in finding effective natural anxiolytic (anti-anxiety) treatments with a lower risk of adverse effects or withdrawal.

METHODS

An electronic and manual search was performed through MEDLINE/PubMed and EBSCO. Articles were not discriminated by date of publication. Available clinical studies published in English that used human participants and examined the anxiolytic potential of dietary and herbal supplements were included. Data were extracted and compiled into tables that included the study design, sample population, intervention, control, length of treatment, outcomes, direction of evidence, and reported adverse events.

RESULTS

A total of 24 studies that investigated five different CAM monotherapies and eight different combination treatments and involved 2619 participants met the inclusion criteria and were analyzed. There were 21 randomized controlled trials and three open-label, uncontrolled observational studies. Most studies involved patients who had been diagnosed with either an anxiety disorder or depression (n = 1786). However, eight studies used healthy volunteers (n = 877) who had normal levels of anxiety, were undergoing surgery, tested at the upper limit of the normal range of a trait anxiety scale, had adverse premenstrual symptoms or were peri-menopausal, reported anxiety and insomnia, or had one month or more of elevated generalized anxiety. Heterogeneity and the small number of studies for each supplement or combination therapy prevented a formal meta-analysis. Of the randomized controlled trials reviewed, 71% (15 out of 21) showed a positive direction of evidence. Any reported side effects were mild to moderate.

CONCLUSIONS

Based on the available evidence, it appears that nutritional and herbal supplementation is an effective method for treating anxiety and anxiety-related conditions without the risk of serious side effects. There is the possibility that any positive effects seen could be due to a placebo effect, which may have a significant psychological impact on participants with mental disorders. However, based on this systematic review, strong evidence exists for the use of herbal supplements containing extracts of passionflower or kava and combinations of L-lysine and L-arginine as treatments for anxiety symptoms and disorders. Magnesium-containing supplements and other herbal combinations may hold promise, but more research is needed before these products can be recommended to patients. St. John's wort monotherapy has insufficient evidence for use as an effective anxiolytic treatment.

Publication trends in the medical informatics literature: 20 years of "Medical Informatics" in MeSH

Background

The purpose of this study is to identify publication output, and research areas, as well as descriptively and quantitatively characterize the field of medical informatics through publication trend analysis over a twenty year period (1987–2006).

Methods

A bibliometric analysis of medical informatics citations indexed in Medline was performed using publication trends, journal frequency, impact factors, MeSH term frequencies and characteristics of citations.

Results

There were 77,023 medical informatics articles published during this 20 year period in 4,644 unique journals. The average annual article publication growth rate was 12%. The 50 identified medical informatics MeSH terms are rarely assigned together to the same document and are almost exclusively paired with a non-medical informatics MeSH term, suggesting a strong interdisciplinary trend. Trends in citations, journals, and MeSH categories of medical informatics output for the 20-year period are summarized. Average impact factor scores and weighted average impact factor scores increased over the 20-year period with two notable growth periods.

Conclusion

There is a steadily growing presence and increasing visibility of medical informatics literature over the years. Patterns in research output that seem to characterize the historic trends and current components of the field of medical informatics suggest it may be a maturing discipline, and highlight specific journals in which the medical informatics literature appears most frequently, including general medical journals as well as informatics-specific journals.