***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The aim of this study was to determine if aromatherapy could reduce preoperative anxiety in ambulatory surgery patients . A total of 109 preoperative patients were r and omly assigned to experimental ( bergamot essential oil ) and control ( water vapor ) conditions and their responses to the State Trait Anxiety Inventory and vital signs were monitored . Patients were stratified by previous surgical experience , but that did not influence the results . All those exposed to bergamot essential oil aromatherapy showed a greater reduction in preoperative anxiety than those in the control groups . Aromatherapy may be a useful part of a holistic approach to reducing preoperative anxiety before ambulatory surgery Background : Recently , Silexan , a patented active substance comprised of an essential oil produced from Lav and ula angustifolia flowers , has been authorized in Germany as a medicinal product for the treatment of states of restlessness related to anxious mood . Its efficacy has been shown in several forms of anxiety disorders . Findings from pre clinical and clinical studies attribute a major role to the serotonin-1A receptor in the pathogenesis and treatment of anxiety . Methods : To eluci date the effect of Silexan on serotonin-1A receptor binding , 17 healthy men underwent 2 positron emission tomography measurements using the radiolig and [carbonyl-11C]WAY-100635 following the daily intake of 160 mg Silexan or placebo for a minimum of 8 weeks ( r and omized , double-blind , cross-over design ) . Additionally , structural magnetic resonance imaging and voxel-based morphometry analysis was performed to determine potential effects on gray matter microstructure . Results : Serotonin-1A receptor binding potential was shown to be significantly reduced following the intake of Silexan compared with placebo in 2 large clusters encompassing the temporal gyrus , the fusiform gyrus and the hippocampus on one h and as well as the insula and anterior cingulate cortex on the other h and . No effects of Silexan on gray matter volume could be detected in this investigation . Conclusion : This positron emission tomography study proposes an involvement of the serotonin-1A receptor in the anxiolytic effects of Silexan . The study was registered in the International St and ard R and omized Controlled Trial Number Register as IS RCT N30885829 ( http://www.controlled-trials.com/is rct n/ ) CONTEXT A prior national survey documented the high prevalence and costs of  alternative medicine use in the United States in 1990 . OBJECTIVE To document trends in alternative medicine use in the United States between 1990 and 1997 . DESIGN Nationally representative r and om household telephone surveys using comparable key questions were conducted in 1991 and 1997 measuring utilization in 1990 and 1997 , respectively . PARTICIPANTS A total of 1539 adults in 1991 and 2055 in 1997 . MAIN OUTCOMES MEASURES Prevalence , estimated costs , and disclosure of alternative therapies to physicians . RESULTS Use of at least 1 of 16 alternative therapies during the previous year increased from 33.8 % in 1990 to 42.1 % in 1997 ( P < or = .001 ) . The therapies increasing the most included herbal medicine , massage , megavitamins , self-help groups , folk remedies , energy healing , and homeopathy . The probability of users visiting an alternative medicine practitioner increased from 36.3 % to 46.3 % ( P = .002 ) . In both surveys alternative therapies were used most frequently for chronic conditions , including back problems , anxiety , depression , and headaches . There was no significant change in disclosure rates between the 2 survey years ; 39.8 % of alternative therapies were disclosed to physicians in 1990 vs 38.5 % in 1997 . The percentage of users paying entirely out-of-pocket for services provided by alternative medicine practitioners did not change significantly between 1990 ( 64.0 % ) and 1997 ( 58.3 % ) ( P=.36 ) . Extrapolations to the US population suggest a 47.3 % increase in total visits to alternative medicine practitioners , from 427 million in 1990 to 629 million in 1997 , thereby exceeding total visits to all US primary care physicians . An estimated 15 million adults in 1997 took prescription medications concurrently with herbal remedies and /or high-dose vitamins ( 18.4 % of all prescription users ) . Estimated expenditures for alternative medicine professional services increased 45.2 % between 1990 and 1997 and were conservatively estimated at $ 21.2 billion in 1997 , with at least $ 12.2 billion paid out-of-pocket . This exceeds the 1997 out-of-pocket expenditures for all US hospitalizations . Total 1997 out-of-pocket expenditures relating to alternative therapies were conservatively estimated at $ 27.0 billion , which is comparable with the projected 1997 out-of-pocket expenditures for all US physician services . CONCLUSIONS  Alternative medicine use and expenditures increased substantially between 1990 and 1997 , attributable primarily to an increase in the proportion of the population seeking alternative therapies , rather than increased visits per patient Background Foeniculum vulgare locally known as ensilal , is an aromatic plant widely cultivated in temperate and tropical regions . The anti-anxiety activity of the crude extract of F. vulgare has been reported . However , the fraction responsible for anxiolytic activity is not known and there is no any report on the anti-anxiety activity of the essential oil of F. vulgare . The objective of study was to evaluate the anxiolytic activity of the essential oil of Foeniculum vulgare Miller . Methods Adult Swiss albino male mice were r and omly divided into six groups ( n = 6 ) . Groups I and II received Tween 80 ( 5 % , v/v ) and diazepam ( 0.5 mg/kg , ip ) , respectively , while groups III to V received orally 50 , 100 , and 200 and 400 mg/kg doses of the essential oil of F. vulgare , respectively . The mice were then individually placed in animal anxiety models : elevated plus maze ( EPM ) , staircase test ( SCT ) and open field test ( OFT ) and evaluated for various parameters . Results In EPM test , 100 and 200 mg/kg doses of the essential oil significantly increased percent number of entries and time spent in open arms compared to control . In SCT these doses also reduced rearing significantly compared to controls , while only the 200 mg/kg dose significantly increased number of squares crossed at the center in the OFT test . Conclusion The essential oil of F. vulgare was found to exhibit a promising anxiolytic activity Essential oils have been used as remedies for a long time in different cultures across the world . However , scientific proof of such application is scarce . We included 72 patients between the ages of 22 and 57 while waiting for dental treatment in our study . The participants were assigned to either a control group ( 14 men , 23 women ) or to an odor group ( 18 men and 17 women ) . Ambient odor of orange was diffused in the waiting room through an electrical dispenser in the odor group whereas in the control group no odor was in the air . We assessed by means of self-report demographic and cognitive variables , trait and state anxiety , and current pain , mood , alertness , and calmness . In this study , we report that exposure to ambient odor of orange has a relaxant effect . Specifically , compared to the controls , women who were exposed to orange odor had a lower level of state anxiety , a more positive mood , and a higher level of calmness . Our data support the previous notion of sedative properties of the natural essential oil of orange ( Citrus sinensis ) OBJECTIVES To review the effect of lavender scent on anticipatory anxiety in dental participants . METHODS In a cluster r and omized-controlled trial , patients ' ( N = 340 ) anxiety was assessed while waiting for a scheduled dental appointment , either under the odor of lavender or with no odor .  Current anxiety , assessed by the brief State Trait Anxiety Indicator ( STAI-6 ) , and generalized dental anxiety , assessed by the Modified Dental Anxiety Scale ( MDAS ) were examined . RESULTS Analyses of variance ( anovas ) showed that although both groups showed similar , moderate levels of generalized dental anxiety ( MDAS F((1,338 ) ) = 2.17 , P > 0.05 ) the lavender group reported significantly lower current anxiety ( STAI : F((1,338 ) ) = 74.69 , P < 0.001 ) than the control group . CONCLUSIONS Although anxiety about future dental visits seems to be unaffected , lavender scent reduces state anxiety in dental patients Inhalation of various essential oils elicits behavioral changes as a consequence of a complex central ly coordinated response . To underst and the molecular mechanisms of action of aromatic compounds on emotional responses , we evaluated the stress-induced changes in mouse brain and the efficacy of inhaled essential oil from Lav and ula officinalis ( LvEO ) using two approaches : a behavioral test , and examining the expression levels of selected genes { fast nerve growth factor receptor ( NGFR ) mRNA , activity regulated cytoskeletal-associated protein ( Arc ) mRNA } and proteins { galactokinase 1 ( GLK1 ) and brain-derived neurotrophic factor (BDNF)}. Animals were r and omly divided into 4 groups depending on the treatment given : stress (-)/H2O , stress (-)/LvEO , stress (+)/H2O , and stress (+)/LvEO group . For behavioral testing , using an elevated plus-maze test , significant anxiolytic-like effects were seen in both the stress (-)/LvEO and stress (+)/LvEO groups , indicating that LvEO exerts anxiolytic-like effects regardless of the administration of water immersion stress . On expression analysis , the levels of NGFR and Arc mRNA were significantly lower in animals subjected to stress . Inhalation of LvEO , however , reversed this change , thus suggesting that LvEO negates the impact of stress on gene expression levels . Meanwhile , significant decreases in expression levels were also observed in the stress (-)/LvEO group , which implies that LvEO , when given in a stress-free situation , may act as a stress stimulus . Taken together , our data suggest that inhalation of LvEO exerts bidirectional influences in the central nervous system ( CNS ) of animals , either attenuating the effects of stress or acting as a stressor , depending on the subject state The pharmacological treatment of anxiety has a long and chequered history , and recent years have seen a rich development in the options available to prescribers . Most of the currently used anxiolytic agents act via monoaminergic ( chiefly serotonin ) or amino acid ( GABA or glutamate ) neurotransmitters , and this chapter describes the pharmacology of the major drug groups . Clinical applications are discussed with respect to the five major anxiety disorders , as well as simple phobia and depression with concomitant anxiety . Prospect i ve future developments in the field are considered The anxiolytic efficacy of the orally administered lavender oil preparation Silexan was investigated in generalized anxiety disorder ( GAD ) in comparison to placebo and paroxetine . In this r and omized , double-blind , double-dummy trial 539 adults with GAD according to DSM-5 criteria and a Hamilton Anxiety Scale ( HAMA ) total score ⩾ 18 points participated and received 160 or 80 mg Silexan , 20 mg paroxetine , or placebo once daily for 10 wk . The primary efficacy endpoint was the HAMA total score reduction between baseline and treatment end . The HAMA total score decreased by 14.1 ± 9.3 points for Silexan 160 mg/d , 12.8 ± 8.7 points for Silexan 80 mg/d , 11.3 ± 8.0 points for paroxetine , and 9.5 ± 9.0 points for placebo ( mean ± s.d . ) . Silexan 160 and 80 mg/d were superior to placebo in reducing the HAMA total score ( p < 0.01 ) whereas paroxetine showed a trend towards significance ( p = 0.10 ) in the full analysis set . The difference between paroxetine and placebo was more pronounced in the analysis of observed cases ( HAMA total score reduction : p < 0.01 ) . In the Silexan 160 mg/d group 73/121 patients ( 60.3 % ) showed a HAMA total score reduction ⩾ 50 % of the baseline value and 56 ( 46.3 % ) had a total score < 10 points at treatment end , compared to 70/135 ( 51.9 % ) and 45 ( 33.3 % ) for Silexan 80 mg/d , 57/132 ( 43.2 % ) and 45 ( 34.1 % ) for paroxetine , and 51/135 ( 37.8 % ) and 40 ( 29.6 % ) for placebo . In addition , Silexan showed a pronounced antidepressant effect and improved general mental health and health-related quality of life . Incidence densities of adverse events ( AEs ) were 0. 
    Output:
    
The essential oil with the best profile is Lavendula angustifolia , which has already been tested in controlled clinical trials with positive results .
Citrus aurantium using different routes of administration also showed significant effects in several animal models , and was corroborated by different research groups .
Other promising essential oils are Citrus sinensis and bergamot oil , which showed certain clinical anxiolytic actions ; along with Achillea wilhemsii , Alpinia zerumbet , Citrus aurantium , and Spiranthera odoratissima , which , like Lavendula angustifolia , appear to exert anxiolytic-like effects without GABA/benzodiazepine activity , thus differing in their mechanisms of action from the benzodiazepines .