Therefore, it is important to document ethnomedicinal knowledge of plants before it vanishes completelyIt was found that the inhabitants of the study area used different plant species for the treatment of a wide range of diseases. The most reported diseases from this study area, include coughs, colds, skin infections, stomach disorders, oral diseases, and diarrhea. Data about traditional medicinal uses of plants were collected from 88 informants, including 57 males and 31 females. The local communities residing in the study area were highly dependent on forest produce to fulfil their daily requirements of fuel, food, fodder, shelter, and medicines. After noting the demographic data and literacy rate of the inhabitants, it was found that aged people possessed an immense knowledge of ethnomedicinal plants compared to the younger generation. The rural people of the study area used 110 plant species from 102 genera belonging to 57 families for ethnomedicinal purposes. In this study, it was found that Rosaceae, Asteraceae, and Lamiaceae were the most reported families. The Rosaceae and Asteraceae families had 12 plant species each, followed by the Lamiaceae family with 6 plant species. The Apiaceae, Pinaceae, Brassicaceae, and Solanaceae families each contributed 3 plant species, while the Fabaceae, Ranunculaceae and Polygonaceae families each contributed 4 plant species. The Amaranthaceae, Berberidaceae, Oxalidaceae, Poaceae, Primulaceae, Pteridaceae, Plantaginaceae, Scrophulariaceae and Utricaceae contributed 2 species .Plants remain necessary for people’s well-being, as they provide a significant number of traditional and modern treatments or techniques used in healthcare. Today, the knowledge of wild plants can play an important role worldwide, not only because of their therapeutic properties, but also because they can represent a source of innovative products in many sectors, such as defense of plants from pest disease, bio-preservatives, nutraceuticals, functional foods, cosmetics,trim trays and agrochemical industries . The wild plants are used by the inhabitants of the state for the treatment of diseases related to human beings .

These include ease of access, therapeutic efficacy, and a low cost of health services . Medicinal plants are the primary source of traditional medicine for people living in backward or remote areas of developing countries . Traditional healers have been found to play an essential part in rural people’s primary health care system, as healthcare in these regions treat those with limited affordability and access to modern medication. Plants have always been important to indigenous communities as they provide food, shelter, and fodder. Plants contain a variety of pharmacologically active chemical compounds which are the reason for their medicinal potential .The bioactive substances such as flavonoids, lignin, coumarins, alkaloids, sterols, glycosides, and terpenoids, present in these ethnomedicinal plant species, might contribute to their therapeutic activities . For example, alkaloids, glycosides, rumicin, nepalin, nepodin, and rumicin in R. hastatus, flavonoids, phenolic acids, protocatechuic acid, fatty acids, and carbohydrates in S. nigrum . Taraxacin, taraxacerine, cerylalcohol, lactuce-roltaraxacin, choline, inulin, tannin, etereal oil, vitamin C, xanthophylls, potassium and vitamin A in T. officinale . Alkaloids, amino acids, carbohydrates, protein polymer, carotenoids, and saponins in U. dioica , Curculigenin in C. orchioides . All of these compounds are responsible for their bioactivity, such as antibacterial, antidiabetic, wound healing, hepatoprotective, and anti-inflammatory properties . The essential oil extracted from the aerial part of A. vestita is very well-known for its anti-inflammatory properties . The cannabinoids in C. sativa have anti-inflammatory properties , and the compounds extracted from the parts of C. bursa-pastoris confirm its anti-inflammatory properties . The phytochemical study of C. dactylon revealed details of its constituents like flavonoids, glycosides, alkaloids, tannins, flavonoids etc. are responsible for its dermatological action . Similarly, the anti-diabetic activities of A. parviflorahave been confirmed by various researchers . Several studies have revealed that today’s youth are uninterested in the traditional medical system . They have little or no knowledge of plants, not even about the species of plants found in their surroundings.

Only a few old people are left to pass on their knowledge to the next generation, but it has not been very effective . The knowledge of medicinal plants of the Himalayan region has been reduced due to the absence of proper documentation and knowledge in the present-day generation . Therefore, it is important to preserve ethnomedicinal knowledge by documenting literature and by proper interaction with the younger generation. Cannabis policy is a topic of constant discussion and changes worldwide. This is because, notwithstanding the coordinated efforts to disrupt cannabis market, both supply and consumption indicators have constantly increased over the past decades . It is estimated that in Europe around 15% of young adults used cannabis in 2019, and the prevalence reaches 19% when only 15- to 24-year-olds are considered . Since 2013, Uruguay, 10 jurisdictions in the United States and Canada have passed laws that license the production and retail sale of cannabis to adults for non-medical purposes, often referred to as recreational use. In parallel, a renewed debate about reforms to the national cannabis policies has developed in Europe . In fact, although there is some European Union regulation concerning cannabis trafficking offences, legislative responses to unauthorised cannabis use and minor possession are still primarily responsibility of individual member states and therefore little harmonised . As an example, cannabis policies range from the more liberal example of the Netherlands, with a system of limited distribution, to countries like Hungary, where personal possession of cannabis is punishable with imprisonment. Furthermore, some countries legally treat cannabis like other drugs, whilst in others penalties for cannabis are lower, typically because the level of harm that the use of the drug may cause is taken into consideration . As an outcome, over the past years several European countries have implemented policy reforms modifying the size of the penalties for cannabis possession for personal use: despite a general trend to reduce punishments, few countries moved in the opposite direction. Some countries have reduced penalties for low-level offences, have removed criminal sanctions for possession or use, or have introduced formal or informal procedures that decrease the likelihood of sanctions being applied . Others have increased penalties for personal possession, either treating them as criminal or administrative offences . This results in a variety of policy approaches running in parallel in Europe, which range from administrative to criminal offences for personal cannabis possession , with the notable exception of the Dutch system.

The potential effect of policy reforms to the treatment of cannabis possession for recreational use on rates of cannabis use is a topic of considerable debate . However, empirical research on the effects of the different types of control policies is still limited . Gathering scientific evidence firstly on whether and which type of cannabis policy reforms are able to affect the availability of the substance and the prevalence of use, and secondly by which type of users and by how much seems crucial in order to understand their public health impacts . In particular, while cannabis policy changes are currently limited to adults, increasing attention is being devoted to the effects that these might have on adolescents . This is because cannabis is by far the most popular illicit substance among youth, particularly in Europe, where adolescents report high rates of easy access to the substance and show higher prevalence of cannabis use compared to the adult population . Furthermore, research shows that initiation into cannabis use typically occurs during the mid to late teens and that there is a strong positive relationship between early first use and the length and intensity of cannabis consumption during adulthood , with a range of possible associated poorer outcomes later in life . In general, policies ruling cannabis related offences are primarily targeted at adults and some authors suggest that they do not affect adolescent consumption . Despite this, several authors suggest that policy changes might indirectly affect adolescents by modifying their access to cannabis and by contributing to shape the social norms of a society . Most of the existing studies on cannabis use associated with cannabis control policy reforms has been conducted in the United States, Australia and Canada, and mainly focused on the adult population. The most recent studies analysing the possible effects of drug policies on youth participation have investigated two specific types of policy changes, i.e., legalisation of cannabis for recreational purposes and legalisation of medical cannabis . Findings are mixed, and overall they suggest that the passage of the laws did not relevantly affect youth. In Europe, due to the scarcity of comparable data, very little work has been performed, and mainly focused on a single-country perspective . To the best of our knowledge, only one study examined the associations between country-level cannabis control policies and cannabis use in the adolescent population including many European countries . Although results suggested that liberalisation policies in general were associated with higher odds of some measures of adolescent cannabis use, a later study conducted on the same data did not confirm this result .

Despite the scarcity of previous studies, Europe constitutes an interesting case for conducting this type of research, particularly because the cannabis law reforms passed over the last 20 years in many countries generated significant variations in the intensity and trajectory of policy changes , vertical grow system which offer and optimal ground for research . Although data to assess the implementation and evolution of policies “on the ground” are limited, recent studies have highlighted the importance of paying attention to variability in specific policy provisions when trying to evaluate their effects, instead of using simple categorisations, for example binary variables to classify legalisation and non-legalisation . Although challenging, the European case offers an optimal setting for this exercise.In this study, we examine the association between changes in cannabis control policies and changes in adolescent perceived availability and self-reported use of cannabis in 20 European countries over a period of more than 15 years . specifically, we reviewed existing literature to characterize the types of cannabis control policy changes in each country, and applied a Differences-in-Differences model to a novel database of the European school Survey on Alcohol and other Drugs . The DiD is a popular statistical technique that attempts to mimic an experimental research design using observational study data. It allows to find the effects of an intervention on specific outcomes, by comparing the differences in outcomes after and before the intervention between treated and untreated groups of units. In our context, DiD is applied to statistically assess the association between types of cannabis policy changes and cannabis perceived availability and use among adolescents . The main contribution of this paper is to address the scarcity of an European perspective in the study of the links between cannabis policy reforms and cannabis-related outcomes among adolescent. We aim to do so by going beyond a simple categorisation of policy changes and try to capture their variability. Also, to better investigate their links with adolescent perceived availability and use, we take into account different patterns of cannabis use. In fact, as for adults, also when focusing on teenagers, it is important to acknowledge that cannabis market is segmented into a number of different types of consumers and that they might react to the same policy in different ways .Data from the European school Survey Project on Alcohol and other Drugs were used in this study. ESPAD is a repeated cross-sectional multinational survey conducted every four years since 1995, designed to provide nationally representative and comparable data on substance use and other risk behaviours among 16 years-old students in Europe . In this survey, a cluster sampling design is used to sample the students who turn 16 years of age in the given survey year. In the majority of countries, class is the last unit in a multistage stratified sampling procedure.

Participating countries adhere to common research guidelines to guarantee consistency in sampling, questionnaires, and survey implementation, and conform to the respective national ethics and data protection regulations. A standardised anonymous questionnaire is voluntarily completed in the classroom setting with paper-and-pencil or computer-assisted format. Sampling frame coverage, school, class and student participation rates were generally high in the considered period. Detailed information about survey representativeness, data collection methodology, and country participation rates in each survey year are reported in the dedicated reports . For the present analysis, starting from the individual level data about 306,693 students from 20 countries collected in five ESPAD data collection waves , annual prevalences were calculated for each country for the set of variables referring to cannabis use and perceived availability, obtaining a balanced panel covering 20 countries in the interval 1999–2015 .