Our Gateway Drug Study
Since I forgot to post the results of the_armadillo and I's study from earlier this year, here you go. Enjoy!
I apologize if the tables are difficult to read.. LJ can be difficult when it comes to that sort of thing. The spaces don't want to stay, and if I try "rich text" mode, I'm told the paper is too large to post. The graphs worked because I was able to save them as jpegs.
-----
Gateway Drug Precedence:
Investigating Sequences of Use
Introduction
Marijuana, the most widely used of illicit drugs in America (SAMHSA 2005; Marijuana 1988; Labouvie 2002), is commonly presented as “the gateway drug.” The concept of a “gateway drug” is the assumption that individuals will progress from using a lower-stage drug to upper-stage drugs in sequence; that a person is unlikely to proceed to an upper-stage drug without having first tried a lower-stage drug (Labouvie 2002). Our survey-based study operates under the assumption that gateway theory itself is valid (as indicated in our literature review), but with the theory that it may not be presented accurately. Our research question asks if there are correlations between the precedence and sequence of individual illegal drug use, and if there are any trends regarding the sequence in which respondents in our sample used illegal drugs.
For this study, we considered the three drug categories that are most prominent in America (SAMHSA 2005) as lower-stage drugs, with all other drug categories listed below as upper-stage drugs. Our lower-stage drugs are tobacco, alcohol, and marijuana. The upper-stage drug categories include: amphetamines, cocaine, hallucinogens, heroin, inhalants, and non-prescribed medical drugs (SAMHSA 2005). The focus of this descriptive analysis was on the relationships between the drugs. It is important to note that this study is not making any determinations of causality, but instead illuminating trends within gateway theory indicating that marijuana may not be the sole - or even the primary - initiator of upper-stage drug use. If alcohol or tobacco is identified as the primary catalyst, and gateway theory is valid, America’s defenses against upper-stage drug use may be spending a lot of money and effort on an errant cause.
Literature Review
Previous academic research indicates that marijuana is not usually the initial drug used by those who have used upper-stage drugs, observing instead that the sequence is usually initiated with alcohol (Hawkins 2002; Kandel 2002; Labouvie 2002; Rebellon 2006). This was the strongest common theme in our research review, but three articles ignored tobacco use in their studies (Hawkins 2002; Labouvie 2002; Rebellon 2006). This is something we aimed to bring into our own study: being sure not to exclude any drug category. Two of the articles used adolescents exclusively as their sampling frame; interesting, but likely producing data that does not directly relate to our own study (Hawkins 2002; Labouvie 2002). Adolescents may not have had the time or the money to be exposed to or purchase many upper-stage drugs, depending on the ages that are under observation.
There was plenty of mass media to be found referring to marijuana as “The Gateway Drug,” but our research team could not find any academic studies supporting this. The only item from a reputable source that we did locate claiming this was a brochure distributed by the U.S. Customs Service, which stated, “Marijuana is the gateway into further illegal-drug usage” (Marijuana 1988). The brochure did not offer any related data, nor did it provide citations that would have allowed us to further pursue evidence supporting the statement.
While marijuana is not the initial drug of precedence in these studies, it is certainly not disregarded as a factor. Three of the pieces directly remind us that marijuana is still prevalently used prior to the use of upper-stage drugs. That is to say, it was used prior to using upper-stage drugs, but not necessarily used prior to using tobacco or alcohol (Golub 2005; Kandel 2002; Labouvie 2002). One article suggests that both prior tobacco use and prior alcohol use were predictors of marijuana initiation more than marijuana use predicting the use of tobacco and alcohol (Hawkins 2002).
None of the articles in our literature review claimed to identify causality in their reports, and neither do we. It is important to keep in mind that there are factors beyond the use of lower-stage drugs that go into an individual’s choice to abuse any substance. Some of these are pointed out in an appendix to this report. Indeed, one research article showed evidence that the elimination of perceived gateway substances may not necessarily reduce subsequent upper-stage drug use at all (Golub 2002).
Data and Methodology
Based on information synthesized from our literature review, we expected to find a strong correlation between the initial use of marijuana preceding the use of upper-stage drugs, but also that there is an equal or greater correlation between initial use of tobacco or alcohol preceding the use of upper-stage drugs. The way we decided to investigate this was to issue a survey to individuals who currently use or had ever used an upper-stage drug. This population was chosen because, due to the nature of this project as a class assignment, there were restrictions on time and money, which prevented us from surveying a larger, random sample. The result was a more refined and focused study that looked only at the order of use of drugs amongst those who had used upper-stage drugs, with no data regarding those who only used one or more of the lower-stage drugs, and no data that could be used to evaluate the validity of gateway theory itself.
As many of the upper-stage drugs are illegal, a sample of individuals who had engaged in their use was a challenge to find. We ended up using a blend of convenience and snowball sampling by making the survey available to be taken anonymously online. We advertised the survey in a number of drug-related communities on a popular blogging site, and asked individuals whom we knew personally to take the survey and encourage people they knew to participate. Additionally, we contacted a dozen rehabilitation clinics that included drug use as a focus, asking them if we could arrange to administer the survey to their clients. One of the organizations ended up participating and distributed physical copies of the survey to a number of their clients. Overall we had a sample set of 224 usable respondents. The primary questions guiding our research were:
· Are there any correlations between precedence and sequence of individual illegal drug usage?
· Are there any sequential trends in which respondents in our sample used illegal drugs?
Our primary independent variables included upper-stage drug use as a collective and also usage of each individual upper-stage drug category, each of which were compared against our primary dependent variables. The dependent variables we used include the use of each of tobacco, alcohol and marijuana as the drug of precedence. While it is normal to use the independent variables as the variable that comes chronologically first, we intentionally switched this around to establish for each upper-stage drug what was most likely to have been used first. To help clarify, we can sum this up in a statement: Those who have used an upper-stage drug are more likely to have first used one of the following: alcohol, tobacco or marijuana. It would not have worked to analyze the other way -- saying that usage of each of the lower-stage drugs made it more likely for respondents to use an upper-stage drug -- because we had no respondents who did not use upper-stage drugs; there would be no variance. Based on our review of literature, we hypothesized that an individual who had used one or more upper-stage drugs was more likely to have initially used alcohol, specifically.
To determine the order in which our respondents used drugs, we included a question in which we asked the age of first use for each drug or drug category. The intent behind this was so that the respondent was not turned on to the fact that we were specifically investigating drug precedence, because we thought that some might be inclined to be less honest when faced with a controversial topic such as gateway theory. This could have been a mistake, as we found out quickly that many people had tried more than one drug in their first year of drug use, making it impossible to determine exactly which drug came first for a number of respondents. Out of 224 respondents 73 had marked down more than one drug of precedence. To deal with this, we filtered the multiple initial-drug respondents out of the data, leaving us with 151 people who had used only one drug of precedence. In every step of data processing, we compared the group of 224 against the group of 151 to see if it made a difference. While the numbers were different, the ratios remained very similar, and the most important part - the sequences - remained exactly the same. Most of our data presented in the finding section of this report reflects the larger set of 224 respondents; we will note if a table or chart is drawn from the group of 151.
In addition to the variables that related to our primary research questions, we also included questions in the survey intended to help gauge the availability of each drug category and the self-identified reasons each respondent had given for why they used the drug. To evaluate the accessibility of a drug category, we asked the respondents to rate the difficulty they had in acquiring that drug as easy to get, troublesome to get, very difficult to get, or nearly impossible to get. To determine the reasons our respondents gave for using the drugs, we asked them to choose all that apply of five of the most common reasons for drug use in America and also a space for them to write in case they felt a separate reason was applicable (see Appendix A: Self-Identified Reasons for Use).
Some other, less useful variables we looked at included the respondents’ sex and current ages. While we had originally intended to examine the relationship between sex and precedence of drug use to look for correlations, there were no distinguishable differences between male and female responses. The current age of the respondents was not useful either, for two reasons. First and foremost, because we were looking at what age the respondents first used drugs, their current age was irrelevant. In addition to this, our internet-based respondents ended up being almost exclusively between the ages of 20 and 35; similar to the age distribution of registered users on the blogging site we advertised with.5
Research Findings
Out of our pool of 224 respondents, the breakdown of percentages of respondents who had used each drug category is shown in Table 1: Drug Use Percentages. In this, all three lower-stage drugs hold true to their status as the most commonly used drugs, with 98% of respondents having used alcohol, 97% having used marijuana, and 88% having used tobacco.
Table 1:
Drug Use Percentages
Drug Percentage of Total Respondents
Alcohol 98%
Marijuana 97%
Tobacco 88%
Hallucinogens 81%
Non-Prescription 72%
Cocaine 60%
Amphetamines 53%
Inhalants 28%
Heroin 19%
Total Respondents: 224
Table 2: Age of First Use shows the average, median, and mode ages of respondents when they first tried each category of drug. Once more, alcohol, tobacco and marijuana are the leaders, all of which being first used at younger ages than the first use for any of the upper-stage drugs. Note at this point that all of the drugs, when first used, were used unlawfully (being as marijuana is illegal in America, and legal smoking and drinking ages are 21 and 18, respectively.) This may have had an effect on the availability of the lower-stage drugs, which we will look at shortly when we examine drug accessibility.
Table 2:
Age of First Use
Mean Years of Age Median Years of Age Mode Years of Age
Alcohol 14.3 15 14
Tobacco 15.2 15 13
Marijuana 16.2 16 16
Inhalants 16.5 16 18
Hallucinogens 17.9 17 16
Non-Rx 18.1 18 18
Amphetamines 19.3 18 18
Cocaine 19.2 19 18
Heroin 20.8 20 18
Figure 1: Overall Drugs of Precedence illustrates the first look at actual precedence, identifying the overall breakdown of drugs of precedence. In this chart, we can see that over half (52%) of all respondents used alcohol before they used any of the other drugs in the study. After alcohol comes tobacco, representing 28% of the respondents, with marijuana in third place, initiating only 9% of the respondents. In fact, more respondents used an upper-stage drug first of all than used marijuana first (12% vs. 9%).
Figure 1:
Overall Drugs of Precedence
While this provided a strong case for alcohol as the primary drug of precedence, we examined how the data was distributed for each individual drug category as well. This is shown in Table 3: Categorical Lower-Stage Drug Precedence. You can see here that for every category of upper-stage drug, alcohol was the primary drug of precedence. Each row represents one of the upper-stage drug categories and the percentages within that category of the precedence of each of the lower-stage drugs. For example, under the heading “Inhalants,” 68% of respondents who had used an inhalant used alcohol first, 45% of respondents who had used an inhalant used tobacco first, and 19% of respondents who had used an inhalant used marijuana first. In each category, alcohol is more precedent than tobacco by at least 10%, and tobacco is more precedent than marijuana by at least 15% (ergo, in all cases, alcohol shows at least 25% more precedence than marijuana). The column on the right (P =) shows the statistical significance of each figure according to a chi-square analysis using the SPSS data analysis program.
Table 3:
Categorical Lower-Stage Drug Precedence
Ever Used Precedence Drug First Used Percentage of Drug Total
Inhalants Tobacco 28 45%
Total: 62 Alcohol 42 68%
Marijuana 12 19%
Amphetamines Tobacco 51 43%
Total: 118 Alcohol 62 52%
Marijuana 38 32%
Cocaine Tobacco 65 48%
Total: 135 Alcohol 79 58%
Marijuana 40 30%
Heroin Tobacco 17 40%
Total: 42 Alcohol 21 50%
Marijuana 12 29%
Hallucinogens Tobacco 78 43%
Total: 182 Alcohol 109 60%
Marijuana 48 26%
Non-Rx Tobacco 73 45%
Total: 161 Alcohol 92 57%
Marijuana 43 27%
Total Respondents: 224
Even though the data here shows a strong case for alcohol as the primary drug of precedence, the statistical significance does not support it in most cases. We suspect that because of the way we processed the data, the analysis was skewed; the variables were processed in reverse from the standard method (as mentioned earlier), and our sample was drawn without any respondents who did not use upper-stage drugs.
To take an even closer look at marijuana in particular, we used the notion suggested in one article that indicated tobacco and alcohol as precedent to marijuana use (Hawkins 2002). Figure 2: Drugs First Used by Respondents Who Used Marijuana shows how precedence is broken down within lower-stage drugs alone. 50.3% of marijuana-users first used alcohol,
29.4% of marijuana-users first used tobacco, 11.2% of marijuana-users first used an upper-stage drug, and 9.8% of marijuana users started out with marijuana. Do note that this is still only representative of a population that has also used upper-stage drugs. It is possible that individuals who have only used lower-stage drugs (not found in our study) may show a different trend.
One might assume that because alcohol and tobacco are not outlawed that they are easier to acquire, which may be suggested as a reason for their strong presence. With this idea in mind, our final chart, Figure 3: Level of Difficulty in Obtaining Drugs, shows that respondents had very nearly equal levels of difficulty acquiring alcohol as marijuana. Likely, as reflected in the starting ages, this could be because alcohol was also illegal at its common starting age.
Conclusions
Our findings show that the first drug used by individuals who have ever used an upper-stage drug was predominantly alcohol, followed by tobacco, followed by marijuana. This holds true for every individual upper-stage drug category as well. Within these three drugs of highest precedence, marijuana was used 80% of the time after having first used alcohol or tobacco. These results establish a strong case for alcohol to be defined as “the gateway drug” more so than the commonly accepted marijuana. While legality of each of the lower-stage drugs may have played a role in their precedence, respondents found alcohol and marijuana to be equally difficult to acquire. At the time of first use for most respondents, both were unlawful to possess. The analysis is not shown to be statistically significant (possibly due to experimenter error), so should not be applied to the greater drug-using population. Even so, our figures are concurrent with our literature review, which indicated similar trends. According to the data we processed, the concept of marijuana as the sole initiator of upper-stage drug use does not stand up against alcohol or tobacco.
References:
Golub, Andrew and Bruce D. Johnson. 2002. “Substance Use Progression and Hard Drug Use in Inner-City New York.” Pp. 90-114 in Stages and Pathways of Drug Involvement: Examining the Gateway Hypothesis. Denise B. Kandel. Cambridge University Press.
Golub, Andrew; Johnson, Bruce D.; Dunlap, Eloise. 2005. “Subcultural Evolution and Illicit Drug Use.” Addiction Research & Theory Vol. 13, Issue 3:217-229.
Hawkins, J. David; Hill, Karl J.; Guo, Jie; Battin-Pearson, Sarah R. 2002. “Substance Use Norms and Transitions in Substance Use: Implications for the Gateway Hypothesis.” Pp. 42-64 in Stages and Pathways of Drug Involvement: Examining the Gateway Hypothesis. Denise B. Kandel. Cambridge University Press.
Kandel, Denise B. and Kazuo Yamaguchi. 2002. “Stages of Drug Involvement in the U.S. Population.” Pp. 65-89 in Stages and Pathways of Drug Involvement: Examining the Gateway Hypothesis. Denise B. Kandel. Cambridge University Press.
Labouvie, Erich and Helen R. White. 2002. “Drug Sequences, Age of Onset, and Use Trajectories as Predictors of Drug Abuse/Dependence in Young Adulthood.” Pp. 19-41 in Stages and Pathways of Drug Involvement: Examining the Gateway Hypothesis. Denise B. Kandel. Cambridge University Press.
Marijuana - The Gateway Drug. 1988. U.S. Customs Service Drug Awareness Program.
Rebellon, Cesar J. and Karen Van Gundy. 2006. “Can Social Psychological Delinquency Theory Explain the Link Between Marijuana and Other Illicit Drug Use? A Longitudinal Analysis of the Gateway Hypothesis. Journal of Drug Issues Vol. 36, Issue 3:515-539.
SAMHSA: Substance Abuse and Mental Health Services Administration. (2006). Results from the 2005 National Survey on Drug Use and Health: National Findings (Office of Applied Studies, NSDUH Series H-30, DHHS Publication
End Notes
Labouvie’s definition used the term “higher-stage” instead of “upper-stage.” For the sake of consistency in this report, we decided to use “upper-stage” throughout.
Our own data showed that most people who have used upper-stage drugs first used each drug between the ages of 14 and 20. Depending on how one defines “adolescent,” it may not matter very much that (Hawkins 2002) and (Labouvie 2002) focused on adolescents instead of a broader age range.
Media exposed primarily through television and the Internet.
Data regarding the self-identified reasons for drug use were qualitative and not scientifically approached, so had no direct relevance to our research questions. We included some of these results in Appendix A: Self-Identified Reasons For Use.
The site we used to host our survey was www.freeonlinesurveys.com.
We are not identifying the website for the sake of confidentiality.
We are not identifying the organization for the sake of confidentiality.
I apologize if the tables are difficult to read.. LJ can be difficult when it comes to that sort of thing. The spaces don't want to stay, and if I try "rich text" mode, I'm told the paper is too large to post. The graphs worked because I was able to save them as jpegs.
-----
Gateway Drug Precedence:
Investigating Sequences of Use
Introduction
Marijuana, the most widely used of illicit drugs in America (SAMHSA 2005; Marijuana 1988; Labouvie 2002), is commonly presented as “the gateway drug.” The concept of a “gateway drug” is the assumption that individuals will progress from using a lower-stage drug to upper-stage drugs in sequence; that a person is unlikely to proceed to an upper-stage drug without having first tried a lower-stage drug (Labouvie 2002). Our survey-based study operates under the assumption that gateway theory itself is valid (as indicated in our literature review), but with the theory that it may not be presented accurately. Our research question asks if there are correlations between the precedence and sequence of individual illegal drug use, and if there are any trends regarding the sequence in which respondents in our sample used illegal drugs.
For this study, we considered the three drug categories that are most prominent in America (SAMHSA 2005) as lower-stage drugs, with all other drug categories listed below as upper-stage drugs. Our lower-stage drugs are tobacco, alcohol, and marijuana. The upper-stage drug categories include: amphetamines, cocaine, hallucinogens, heroin, inhalants, and non-prescribed medical drugs (SAMHSA 2005). The focus of this descriptive analysis was on the relationships between the drugs. It is important to note that this study is not making any determinations of causality, but instead illuminating trends within gateway theory indicating that marijuana may not be the sole - or even the primary - initiator of upper-stage drug use. If alcohol or tobacco is identified as the primary catalyst, and gateway theory is valid, America’s defenses against upper-stage drug use may be spending a lot of money and effort on an errant cause.
Literature Review
Previous academic research indicates that marijuana is not usually the initial drug used by those who have used upper-stage drugs, observing instead that the sequence is usually initiated with alcohol (Hawkins 2002; Kandel 2002; Labouvie 2002; Rebellon 2006). This was the strongest common theme in our research review, but three articles ignored tobacco use in their studies (Hawkins 2002; Labouvie 2002; Rebellon 2006). This is something we aimed to bring into our own study: being sure not to exclude any drug category. Two of the articles used adolescents exclusively as their sampling frame; interesting, but likely producing data that does not directly relate to our own study (Hawkins 2002; Labouvie 2002). Adolescents may not have had the time or the money to be exposed to or purchase many upper-stage drugs, depending on the ages that are under observation.
There was plenty of mass media to be found referring to marijuana as “The Gateway Drug,” but our research team could not find any academic studies supporting this. The only item from a reputable source that we did locate claiming this was a brochure distributed by the U.S. Customs Service, which stated, “Marijuana is the gateway into further illegal-drug usage” (Marijuana 1988). The brochure did not offer any related data, nor did it provide citations that would have allowed us to further pursue evidence supporting the statement.
While marijuana is not the initial drug of precedence in these studies, it is certainly not disregarded as a factor. Three of the pieces directly remind us that marijuana is still prevalently used prior to the use of upper-stage drugs. That is to say, it was used prior to using upper-stage drugs, but not necessarily used prior to using tobacco or alcohol (Golub 2005; Kandel 2002; Labouvie 2002). One article suggests that both prior tobacco use and prior alcohol use were predictors of marijuana initiation more than marijuana use predicting the use of tobacco and alcohol (Hawkins 2002).
None of the articles in our literature review claimed to identify causality in their reports, and neither do we. It is important to keep in mind that there are factors beyond the use of lower-stage drugs that go into an individual’s choice to abuse any substance. Some of these are pointed out in an appendix to this report. Indeed, one research article showed evidence that the elimination of perceived gateway substances may not necessarily reduce subsequent upper-stage drug use at all (Golub 2002).
Data and Methodology
Based on information synthesized from our literature review, we expected to find a strong correlation between the initial use of marijuana preceding the use of upper-stage drugs, but also that there is an equal or greater correlation between initial use of tobacco or alcohol preceding the use of upper-stage drugs. The way we decided to investigate this was to issue a survey to individuals who currently use or had ever used an upper-stage drug. This population was chosen because, due to the nature of this project as a class assignment, there were restrictions on time and money, which prevented us from surveying a larger, random sample. The result was a more refined and focused study that looked only at the order of use of drugs amongst those who had used upper-stage drugs, with no data regarding those who only used one or more of the lower-stage drugs, and no data that could be used to evaluate the validity of gateway theory itself.
As many of the upper-stage drugs are illegal, a sample of individuals who had engaged in their use was a challenge to find. We ended up using a blend of convenience and snowball sampling by making the survey available to be taken anonymously online. We advertised the survey in a number of drug-related communities on a popular blogging site, and asked individuals whom we knew personally to take the survey and encourage people they knew to participate. Additionally, we contacted a dozen rehabilitation clinics that included drug use as a focus, asking them if we could arrange to administer the survey to their clients. One of the organizations ended up participating and distributed physical copies of the survey to a number of their clients. Overall we had a sample set of 224 usable respondents. The primary questions guiding our research were:
· Are there any correlations between precedence and sequence of individual illegal drug usage?
· Are there any sequential trends in which respondents in our sample used illegal drugs?
Our primary independent variables included upper-stage drug use as a collective and also usage of each individual upper-stage drug category, each of which were compared against our primary dependent variables. The dependent variables we used include the use of each of tobacco, alcohol and marijuana as the drug of precedence. While it is normal to use the independent variables as the variable that comes chronologically first, we intentionally switched this around to establish for each upper-stage drug what was most likely to have been used first. To help clarify, we can sum this up in a statement: Those who have used an upper-stage drug are more likely to have first used one of the following: alcohol, tobacco or marijuana. It would not have worked to analyze the other way -- saying that usage of each of the lower-stage drugs made it more likely for respondents to use an upper-stage drug -- because we had no respondents who did not use upper-stage drugs; there would be no variance. Based on our review of literature, we hypothesized that an individual who had used one or more upper-stage drugs was more likely to have initially used alcohol, specifically.
To determine the order in which our respondents used drugs, we included a question in which we asked the age of first use for each drug or drug category. The intent behind this was so that the respondent was not turned on to the fact that we were specifically investigating drug precedence, because we thought that some might be inclined to be less honest when faced with a controversial topic such as gateway theory. This could have been a mistake, as we found out quickly that many people had tried more than one drug in their first year of drug use, making it impossible to determine exactly which drug came first for a number of respondents. Out of 224 respondents 73 had marked down more than one drug of precedence. To deal with this, we filtered the multiple initial-drug respondents out of the data, leaving us with 151 people who had used only one drug of precedence. In every step of data processing, we compared the group of 224 against the group of 151 to see if it made a difference. While the numbers were different, the ratios remained very similar, and the most important part - the sequences - remained exactly the same. Most of our data presented in the finding section of this report reflects the larger set of 224 respondents; we will note if a table or chart is drawn from the group of 151.
In addition to the variables that related to our primary research questions, we also included questions in the survey intended to help gauge the availability of each drug category and the self-identified reasons each respondent had given for why they used the drug. To evaluate the accessibility of a drug category, we asked the respondents to rate the difficulty they had in acquiring that drug as easy to get, troublesome to get, very difficult to get, or nearly impossible to get. To determine the reasons our respondents gave for using the drugs, we asked them to choose all that apply of five of the most common reasons for drug use in America and also a space for them to write in case they felt a separate reason was applicable (see Appendix A: Self-Identified Reasons for Use).
Some other, less useful variables we looked at included the respondents’ sex and current ages. While we had originally intended to examine the relationship between sex and precedence of drug use to look for correlations, there were no distinguishable differences between male and female responses. The current age of the respondents was not useful either, for two reasons. First and foremost, because we were looking at what age the respondents first used drugs, their current age was irrelevant. In addition to this, our internet-based respondents ended up being almost exclusively between the ages of 20 and 35; similar to the age distribution of registered users on the blogging site we advertised with.5
Research Findings
Out of our pool of 224 respondents, the breakdown of percentages of respondents who had used each drug category is shown in Table 1: Drug Use Percentages. In this, all three lower-stage drugs hold true to their status as the most commonly used drugs, with 98% of respondents having used alcohol, 97% having used marijuana, and 88% having used tobacco.
Table 1:
Drug Use Percentages
Drug Percentage of Total Respondents
Alcohol 98%
Marijuana 97%
Tobacco 88%
Hallucinogens 81%
Non-Prescription 72%
Cocaine 60%
Amphetamines 53%
Inhalants 28%
Heroin 19%
Total Respondents: 224
Table 2: Age of First Use shows the average, median, and mode ages of respondents when they first tried each category of drug. Once more, alcohol, tobacco and marijuana are the leaders, all of which being first used at younger ages than the first use for any of the upper-stage drugs. Note at this point that all of the drugs, when first used, were used unlawfully (being as marijuana is illegal in America, and legal smoking and drinking ages are 21 and 18, respectively.) This may have had an effect on the availability of the lower-stage drugs, which we will look at shortly when we examine drug accessibility.
Table 2:
Age of First Use
Mean Years of Age Median Years of Age Mode Years of Age
Alcohol 14.3 15 14
Tobacco 15.2 15 13
Marijuana 16.2 16 16
Inhalants 16.5 16 18
Hallucinogens 17.9 17 16
Non-Rx 18.1 18 18
Amphetamines 19.3 18 18
Cocaine 19.2 19 18
Heroin 20.8 20 18
Figure 1: Overall Drugs of Precedence illustrates the first look at actual precedence, identifying the overall breakdown of drugs of precedence. In this chart, we can see that over half (52%) of all respondents used alcohol before they used any of the other drugs in the study. After alcohol comes tobacco, representing 28% of the respondents, with marijuana in third place, initiating only 9% of the respondents. In fact, more respondents used an upper-stage drug first of all than used marijuana first (12% vs. 9%).
Figure 1:
Overall Drugs of Precedence
While this provided a strong case for alcohol as the primary drug of precedence, we examined how the data was distributed for each individual drug category as well. This is shown in Table 3: Categorical Lower-Stage Drug Precedence. You can see here that for every category of upper-stage drug, alcohol was the primary drug of precedence. Each row represents one of the upper-stage drug categories and the percentages within that category of the precedence of each of the lower-stage drugs. For example, under the heading “Inhalants,” 68% of respondents who had used an inhalant used alcohol first, 45% of respondents who had used an inhalant used tobacco first, and 19% of respondents who had used an inhalant used marijuana first. In each category, alcohol is more precedent than tobacco by at least 10%, and tobacco is more precedent than marijuana by at least 15% (ergo, in all cases, alcohol shows at least 25% more precedence than marijuana). The column on the right (P =) shows the statistical significance of each figure according to a chi-square analysis using the SPSS data analysis program.
Table 3:
Categorical Lower-Stage Drug Precedence
Ever Used Precedence Drug First Used Percentage of Drug Total
Inhalants Tobacco 28 45%
Total: 62 Alcohol 42 68%
Marijuana 12 19%
Amphetamines Tobacco 51 43%
Total: 118 Alcohol 62 52%
Marijuana 38 32%
Cocaine Tobacco 65 48%
Total: 135 Alcohol 79 58%
Marijuana 40 30%
Heroin Tobacco 17 40%
Total: 42 Alcohol 21 50%
Marijuana 12 29%
Hallucinogens Tobacco 78 43%
Total: 182 Alcohol 109 60%
Marijuana 48 26%
Non-Rx Tobacco 73 45%
Total: 161 Alcohol 92 57%
Marijuana 43 27%
Total Respondents: 224
Even though the data here shows a strong case for alcohol as the primary drug of precedence, the statistical significance does not support it in most cases. We suspect that because of the way we processed the data, the analysis was skewed; the variables were processed in reverse from the standard method (as mentioned earlier), and our sample was drawn without any respondents who did not use upper-stage drugs.
To take an even closer look at marijuana in particular, we used the notion suggested in one article that indicated tobacco and alcohol as precedent to marijuana use (Hawkins 2002). Figure 2: Drugs First Used by Respondents Who Used Marijuana shows how precedence is broken down within lower-stage drugs alone. 50.3% of marijuana-users first used alcohol,
29.4% of marijuana-users first used tobacco, 11.2% of marijuana-users first used an upper-stage drug, and 9.8% of marijuana users started out with marijuana. Do note that this is still only representative of a population that has also used upper-stage drugs. It is possible that individuals who have only used lower-stage drugs (not found in our study) may show a different trend.
One might assume that because alcohol and tobacco are not outlawed that they are easier to acquire, which may be suggested as a reason for their strong presence. With this idea in mind, our final chart, Figure 3: Level of Difficulty in Obtaining Drugs, shows that respondents had very nearly equal levels of difficulty acquiring alcohol as marijuana. Likely, as reflected in the starting ages, this could be because alcohol was also illegal at its common starting age.
Conclusions
Our findings show that the first drug used by individuals who have ever used an upper-stage drug was predominantly alcohol, followed by tobacco, followed by marijuana. This holds true for every individual upper-stage drug category as well. Within these three drugs of highest precedence, marijuana was used 80% of the time after having first used alcohol or tobacco. These results establish a strong case for alcohol to be defined as “the gateway drug” more so than the commonly accepted marijuana. While legality of each of the lower-stage drugs may have played a role in their precedence, respondents found alcohol and marijuana to be equally difficult to acquire. At the time of first use for most respondents, both were unlawful to possess. The analysis is not shown to be statistically significant (possibly due to experimenter error), so should not be applied to the greater drug-using population. Even so, our figures are concurrent with our literature review, which indicated similar trends. According to the data we processed, the concept of marijuana as the sole initiator of upper-stage drug use does not stand up against alcohol or tobacco.
References:
Golub, Andrew and Bruce D. Johnson. 2002. “Substance Use Progression and Hard Drug Use in Inner-City New York.” Pp. 90-114 in Stages and Pathways of Drug Involvement: Examining the Gateway Hypothesis. Denise B. Kandel. Cambridge University Press.
Golub, Andrew; Johnson, Bruce D.; Dunlap, Eloise. 2005. “Subcultural Evolution and Illicit Drug Use.” Addiction Research & Theory Vol. 13, Issue 3:217-229.
Hawkins, J. David; Hill, Karl J.; Guo, Jie; Battin-Pearson, Sarah R. 2002. “Substance Use Norms and Transitions in Substance Use: Implications for the Gateway Hypothesis.” Pp. 42-64 in Stages and Pathways of Drug Involvement: Examining the Gateway Hypothesis. Denise B. Kandel. Cambridge University Press.
Kandel, Denise B. and Kazuo Yamaguchi. 2002. “Stages of Drug Involvement in the U.S. Population.” Pp. 65-89 in Stages and Pathways of Drug Involvement: Examining the Gateway Hypothesis. Denise B. Kandel. Cambridge University Press.
Labouvie, Erich and Helen R. White. 2002. “Drug Sequences, Age of Onset, and Use Trajectories as Predictors of Drug Abuse/Dependence in Young Adulthood.” Pp. 19-41 in Stages and Pathways of Drug Involvement: Examining the Gateway Hypothesis. Denise B. Kandel. Cambridge University Press.
Marijuana - The Gateway Drug. 1988. U.S. Customs Service Drug Awareness Program.
Rebellon, Cesar J. and Karen Van Gundy. 2006. “Can Social Psychological Delinquency Theory Explain the Link Between Marijuana and Other Illicit Drug Use? A Longitudinal Analysis of the Gateway Hypothesis. Journal of Drug Issues Vol. 36, Issue 3:515-539.
SAMHSA: Substance Abuse and Mental Health Services Administration. (2006). Results from the 2005 National Survey on Drug Use and Health: National Findings (Office of Applied Studies, NSDUH Series H-30, DHHS Publication
End Notes
Labouvie’s definition used the term “higher-stage” instead of “upper-stage.” For the sake of consistency in this report, we decided to use “upper-stage” throughout.
Our own data showed that most people who have used upper-stage drugs first used each drug between the ages of 14 and 20. Depending on how one defines “adolescent,” it may not matter very much that (Hawkins 2002) and (Labouvie 2002) focused on adolescents instead of a broader age range.
Media exposed primarily through television and the Internet.
Data regarding the self-identified reasons for drug use were qualitative and not scientifically approached, so had no direct relevance to our research questions. We included some of these results in Appendix A: Self-Identified Reasons For Use.
The site we used to host our survey was www.freeonlinesurveys.com.
We are not identifying the website for the sake of confidentiality.
We are not identifying the organization for the sake of confidentiality.