A review of trends in alcohol and cannabis use among young people

Title

A review of trends in alcohol and cannabis use among young people

Sections

Introduction
Availability of recent trend studies
Trend studies in North America - 1. Canada
Table 1 Alcohol use trend studies
Table 2 - Cannabis use trend studies
Trend studies in Australia
Trend studies in Scandinavia
1. Denmark
2. Finland
3. Norway
4. Sweden
Trend studies in Mexico
Summary and conclusions
Acknowledgement

Details

Author: R. G SMART, G. F. MURRAY
Pages: 77 to 90
Creation Date: 1981/01/01

A review of trends in alcohol and cannabis use among young people

R. G SMART
G. F. MURRAY
Addiction Research Foundation, Toronto, Ontario, Canaca

Introduction

One of the main uses of epidemiology as outlined by Morris [ 18] is to study the history of the health of populations or trends in disease over time. Currently, there is no source for assessing world-wide trends in alcohol and cannabis use among young people. There are some sources for material on trends in individual countries such as Australia (Champion et al. [ 9] ), Canada (Smart et al. [ 3] ) and the United States (Johnston et al. [ 15] , [ 16] ]). However, there has been no recent analysis of such trends on an international basis. Nor has a truly international study of alcohol use among young people been made. The most recent large compendiums of national drug use studies were made by Mercer and Smart [ 17] and Blumberg [ 6] and they are somewhat out of date. The purpose of this review is to examine available studies which attempt to study cannabis or alcohol use in young populations over time.

The rationale for this review arises from a variety of considerations, among them:

  1. A recent large-scale study by Sulkunen [ 21] of per capita alcohol consumption showed world-wide increases over the years 1950-1975.

However, it is not known whether such increases are reflected in the youthful population or are typical only of adults. Separate per capita consumption figures for different age groups are not available from official government sources and survey data are the only available substitute.

  1. Many studies (see Jessor [ 14] , Whitehead et al. [ 24] , for reviews) showed that cannabis and alcohol use were highly correlated in youthful populations. If alcohol use has increased in a country then cannabis use has probably also increased.

  2. International statistics such as those reported by the Commission on Narcotic Drugs [22, 23] showed substantial increases in total quantities of drugs seized in the world as a whole and in most geographic areas. For example, seizures of cannabis increased from 1,646,611 kg in 1973 to 5,874,130 kg in 1978. This increase most probably reflected increased usage, although it could also have been due to increased enforcement and more efficient police activities.

  3. International agencies, such as the International Narcotics Control Board and the Commission on Narcotic Drugs, frequently make reference to recent trends in cannabis use. These estimates are based on statements made by government representatives at the Commission session, on government reports from various countries and on drug seizure data. More stable and consistent data, however, are likely to be obtained from trends derived from repeated surveys using a standardized methodology and careful sampling procedures.

The main purposes of the current review are therefore to:

  1. Examine the available trend studies for cannabis and alcohol involving young people;

  2. Determine which countries have seen increases over time and which have not;

  3. Indicate the demographic subgroups having the largest number of changes;

  4. Indicate possible future trends;

  5. Identify areas where there is a lack of current information about trends in cannabis and alcohol use.

Availability of recent trend studies

This review was limited to trend studies of large, representative samples of young persons, i.e. reports containing data from different time periods using the same questions and large samples with representative selection. The authors searched the available scientific literature, wrote to national and international agencies and utilized informal contacts in assembling the various studies. Some studies from Scandinavia required translation into English before they could be used. Because there were numerous trend studies found in Canada and the United States, only a few studies with the longest trend times and the largest representative samples were used. Studies on alcohol use were obtained from eight countries: Australia, Canada, Denmark, Finland, Mexico, Norway, Sweden and the United States. Only four countries: Australia, Canada, Norway and the United States had trend studies of cannabis use. The major characteristics of these studies are shown in tables 1 and 2.

Trend studies in North America - 1. Canada

Studies have been conducted in Ontario, Canada, since 1968 (Smart and Fejer [ 20] , Smart et al. [ 3] ) utilizing large stratified proportionate samples of students in grades 7, 9, 11 and 13. The studies carried out in the years 1968 to 1974 took place in Toronto only, but those in 1977 and 1979 used samples from the entire province of Ontario. Sample sizes varied but usually included 1,000 or more students per grade. The percentage of drinkers increased from 46.3 per cent in 1968 to 72.9 per cent in 1974, partly because of a reduction in the drinking age from 21 to 18 in 1971. The percentage of drinkers did not increase for the years 1977 and 1979 (76.3 per cent and 76.9 per cent, respectively) in the provincial study. However, the percentage of heavy drinkers (five or more drinks on one occasion), those getting high and drunk, and those with problems did increase.

Over the years 1968 to 1979 increases in drinking were greatest among females. Both drinking and heavy drinking were most common among males, older students, those with failing grades in school and students with fathers in professional and managerial occupations.

Cannabis use also increased in the years after 1968. In 1968, 6.7 per cent of Toronto students reported cannabis use "in the past 6 months". There was a remarkable increase to 18.3 per cent by 1970; however, some stabilization in the trend occurred with 20.9 per cent in 1972 and 22.9 per cent in 1974. The provincial study found that in 1977 some 25.1 per cent had "reported using cannabis in the past 12 months". Again in 1979, there was a large increase and 31.7 per cent of students reported some usage. Cannabis use increased for both sexes and most age groups between 1977 and 1979. There was a tendency for larger increases in cannabis use among females than males after 1968.

As with alcohol, cannabis use was more common among males, students with lower grades and those with fathers in professional and managerial occupations. However, cannabis use was slightly more common among grade 11 students than among grade 13 students.

2. United States of America

Blackford [ 5] studied trends in alcohol and drug use in a California county, San Mateo, each year since 1968. This study used a complex sampling system, the details of which are not available. The samples ranged in size from 18,774 to 31,251 and included students in grades 7 to 12. Drinkers of alcoholic beverages in grades 9 to 12 increased from 65.4 per cent to 88 per cent of the sample in the years 1968 to 1977. The largest rates of increase were in the years 1968 to 1969. The percentage of students reporting drinking on 10 or more occasions more than doubled in this period (25.4 per cent to 54.7 per cent). Those reporting drinking approximately weekly or more often (50+ times) increased from 15.6 per cent in 1970 to 27.6 per cent in 1977. The highest rates of increase occurred among females and among those in the lower grades.

Table 1 Alcohol use trend studies

 

Prevalence (percentage)

 

Country

Author

Year

Type of sample

Alcohol measures

Whole sample

Males

Females

Major demographic variables associated with alcohol use

Australia
Champion et al.
1978
Students in grade 10. n=504
Percentage reporting current use
1971 = 71.3 1977 = 85.3
   
Friends use (use increases with number of friends who use), sex (males continuing to use more often)
Canada (i)
Smart and Fejer
1975
Students in grades 7, 9, 11, 13 n = 3,479 to 8,865
Percentage reporting use in past 6 months
1968 = 46.3 1974 = 72.9
51.774.8 40.471.0
Age (continued increase with age), sex (males using more often but difference decreasing steadily), occupation of parents (more use by students whose parents are in professional or managerial occupations)
Canada (ii)
Smart et al.
1979
Students in grades 7, 9, 11, 13. n = 4,700
Percentage reporting use in past 6 months
1977 = 76.3 1979 = 76.9
78.579.0 74.374.9
Age (continued increase with age), sex (males using more often but difference decreasing steadily), occupation of parents (more use by students whose parents are in professional or managerial occupations)
Denmark
Smart et al.
1979
Various samples employed
Average annual consumption increased significantly. In fact, consumption doubled between 1960 and 1974
     
Sex (differences declining though make continue to use).
Finland
Ahlstrom-Laakso
1979
Various samples employed
Percentage reporting not using in 4-week period
1973 = 21 1977 = 27 1979 = 34
   
Occupation of parents differences decreasing
Mexico
Castro a
1980
Students between 14 and 18 years n=2,317 to 4,059
Percentage reporting use in past 30 days
1976 = 4.7 1978 = 16.7
2.714.5
1.4 b14.3
Highest percentage of users were 18-year-old males in preparatory school
Norway (i)
Irgens-Jensen et al.
19771979
15- to 21-year-olds n = 729 to 805
Percentage reporting ever used
1972 = 91 1979 = 91
9291 8992
Sex (differences decreasing though males continue to use more)
Norway (ii)
Brun- Gulbrandsen
1978
Various samples employed
Percentage reporting use in past 12 months
1956 = 69 1973 = 93
     
Sweden (i)
Hofsten
1969
High school students 18 years of age on average, n = 1,435
Percentage reporting never used spirits in past 12 months
1956 = 1967 =
3816 4223
Sex (twice as many boys as girls are consumers)
Sweden (ii)
Hibell
1977
Various samples employed
Alcohol consumption
Increases most years 1947-1976
   
Occupation of parents differences decreasing
United States (i)
Johnston et al
1979
High school students, n = 15,791 to 18,924
Percentage reporting use in past 12 months
1975 = 84.8 1979 = 88.1
88.189.7 82.186.5
Geographical regions (differences declining), urban vs. rural (differences declining), sex (differences declining though older male students continue to have greater use), sex (differences declining and moving parallel), attitude toward use (positively related to use)
United States (ii)
Blackford
1978
Students in grades 7 through 12
Percentage reporting use in past 12 months (grade II only)
1968 = 89.5
70.790.2 67.489.5
Grade (continued increasing trend with grade level), sex (highest rate of increase for females and those in lower grades)

Table 2 - Cannabis use trend studies

 

Prevalence (percentage)

 

Country

Author

Year

Type of sample

Cannabis measures

Whole sample

Males

Females

Major demographic variables associated with cannabis use

Australia
Champion et al.
1978
Students in grade 10, n = 504
Percentage reporting current use
1971 = 6.5 1977 = 26.9
   
Sex (males continued using and using more often, but difference between sexes declining), friends use (use increases with number of friends who use)
Canada (i)
Smart and Fejer
1975
Students in grades
Percentage reporting
1968= 6.7
8.6 4.1
Age (continuing increase of use with age), sex
     
7, 9, 11, 13.
use in past 6 months
1974=22.9
25.5 20.3
(differences declining)
     
n = 3,479 to 8,865
         
Canada (ii)
Smart et al.
1979
Students in grades
Percentage reporting
1977 = 25.1
29.4 21.1
Age (continuing increase of use with age), sex
     
7, 9, 11, 13.
use in past 12 months
1979 = 31.7
36.4 26.8
(differences declining)
     
n = 4,700
         
Norway
Irgens-Jensen
1977
15- to 21-year-olds
Percentage reporting
1968 = 5.3
   
Use of other drugs (positive relationship)
 
et al.
1979
n = 729 to 1,027
ever used
1972 = 18.8
     
         
1979 = 22.5
     
United
Johnston et al.
1979
High school
Percentage reporting
1975 = 40.0
45.8 34.9
Geographic regions (differences declining),
States (i)
   
students
use in past 12 months
1979 = 50.8
55.8 45.7
sex (older male students most common users),
     
n = 15,791 to 18,924
       
education (greater use by those not intending to go to college), attitude toward use (positively related to use)
United
Blackford
1978
Students in grades
Percentage reporting
1968 =
36.9 31.7
Grade (continued increasing trend with grade
States (ii)
   
7-12
use in past 12 months
1977 =
65.2 62.8
level), sex (males continuing to use more but
       
(grade 11 only)
     
high rates of increase for females)

The San Mateo studies also inquired about cannabis use. For grades 9 to 12 the percentage of users "in the past 12 months" increased from 31.9 per cent to 57.5 per cent in the years 1968 to 1977. Again, rates of frequent use increased more than did "any" use; 17.5 per cent used cannabis 10 or more times in 1968 as compared with 37.1 per cent in 1977. Rates of increase were higher among females than among males. For example, at almost all grade levels, twice as many females used cannabis in 1977 as in 1968. Although rates of use did not double for any male group, overall rates of use were highest among males and those in grades 11 and 12.

Another American study is the national survey conducted by Johnston et al. [ 15 ] [ 16] since 1975. This study has only been carried out for five years and hence a long-term trend cannot be discerned. Data were collected from high school seniors, using a three-stage sampling procedure. The sample sizes varied from 15,791 to 18,924. Johnston et al. [ 15 ] [ 16] found that there was a small increase in the percentage of drinkers from 1975 to 1979 (90.4 per cent to 93 per cent), little increase in daily use but a considerable increase in heavy use (those having five or more drinks increased from 36.8 per cent in 1975 to 41 per cent in 1979). The average age of starting to drink also decreased slightly. Use of alcohol was most common among males, older students, those living in the north-east and in urban areas. However, recent data showed a narrowing of the gap between urban and rural areas.

This study showed greater increases in cannabis use than in drinking. There was a large increase in numbers of cannabis users in the past 12 months (40 per cent to 50.8 per cent), past 30 days (27.1 per cent to 36.5 per cent) and in proportions of daily users (6 per cent to 10.3 per cent). Also, age at first use was decreasing. Use was most common among males, those not intending to go to college, those living in the north-east and in urban areas. As with alcohol the urban-rural gap in numbers of users was declining. Currently there are far more daily users of cannabis among the seniors than daily drinkers. Also, the probability of future use has increased so that 28 per cent of students probably or definitely expect to use cannabis in 1978 compared with 20 per cent in 1975. 1

Trend studies in Australia

Studies have been conducted in New South Wales since 1971 (Champion et al. [ 9] ). Champion et al. presented trends for approximately 500 tenth-year students by comparing use in 1977 with the 1971 and 1973 figures reported by Bell et al. [ 4] . The sample was gathered by randomly selecting 30 schools and including one in every ten students from years 7 through 11.

1

1979 data not available.

The percentage of tenth-year students using alcohol or cannabis increased steadily between 1971 and 1977. In 1977 proportionally more students than in 1973 reported that all their friends used alcohol, but the most striking change was the increased proportion of students reporting that all or some of their friends used cannabis (30 per cent to 62 per cent). This continued the trend observed between 1971 and 1973. In addition, the students perceiving lack of danger of alcohol increased, though the major trend was for students to reply that alcohol was "only dangerous in excess" rather than "not dangerous". Consistent with these trends, higher proportions of respondents wanted alcohol to be totally prohibited or more restricted as opposed to freely available.

Unlike the situation reported for alcohol, attitudes shifted away from prohibition of cannabis between 1971 and 1977. Similarly, between 1973 and 1977 a trend towards reduced perception of the dangers of cannabis was revealed. For example, in 1977 more respondents replied that the drug was "not dangerous" (28 per cent compared with 14 per cent in 1973).

Trend studies in Scandinavia

Trend studies describing the alcohol habits of young people have been conducted in Denmark, Finland, Norway and Sweden (Ahlstrom-Laakso [ 2] , Brun-Gulbrandsen [ 7] , Hibell [ 10] , Hofsten [ 11] , Irgens-Jensen and others [ 12] , [ 13] , Sindballe [ 19] ). Only in Norway, however, have trend studies been carried out for cannabis use (Irgens-Jensen and others [ 12] , [ 13] ).

1. Denmark

In Denmark a trend study was prepared covering the period from 1960 to 1974 (Sindballe [ 19] ). Five variously developed surveys were employed:

  1. In 1960, 451 14- to 19-year-old males were individually interviewed after being randomly selected from Copenhagen and the surrounding district;

  2. The 14- and 15-year-olds (148) were re-interviewed in 1964 along with an additional 26 18- and 19-year-olds not previously involved;

  3. A survey of 1,381 high school students was conducted in 1963. Questionnaires were distributed in the classrooms of three Arhus schools;

  4. Then, in 1974, two identical questionnaire surveys were conducted in separate counties (Roskilde and Ballerup). In Roskilde, 3,428 12- to 20-year-olds and in Ballerup county 2,009 12- to 18-year-olds were studied.

Although these studies were not directly comparable, Sindballe claimed the strong tendencies revealed warranted the reporting of general trends. The average annual consumption of alcohol increased significantly. In fact, it doubled between 1960 and 1974. During this period the frequency of drinking also increased.

2. Finland

In Finland, a number of study series were also conducted (Ahlstrom-Laakso [ 2] ). In 1960, interviews were conducted among a sample of 14-, 16- and 18-year-old Helsinki boys. Equivalent age groups of boys and girls were mailed questionnaires in 1973. In addition, a supplementary sample of Helsinki boys parallel to the nationwide sample of boys and girls was drawn to ensure comparability and to obtain a sufficient sample size. A second postal questionnaire study was conducted in three later consecutive years (1977 to 1979). In 1977 and 1979, 12-, 14-, 16- and 18-year-olds were studied, but in 1978 only 12- and 14-year-olds were included.

Although the per capita consumption of alcohol more than tripled from 1960 to 1974, virtually no change occurred since 1974. The number of life-long abstaining Helsinki boys decreased substantially between 1960 and 1973, but an increase was reported in the late 1970s among 14- and 16-year-olds who abstained in the 12 months preceding the questionnaire. In particular, the abstinence rate of youths with fathers in lower occupational groups increased. The age of first use fell between 1960 and 1973, but increased slightly in the late 1970s. The age of first use, however, was related to the availability of alcoholic beverages. For example, the age of first use was lowest for regular beer which was available in grocery stores and highest for strong beer which was only available in Alko's retail stores (the government-operated system of stores which regulate over-the-counter sales of alcoholic beverages). The percentage of boys who frequently used alcohol declined to equal the level reported for girls in 1979, and the number of students using alcohol monthly and weekly declined between 1973 and 1979.

3. Norway

In Oslo, Irgens-Jensen and others [12, 13] conducted yearly studies of randomly selected 15- to 21-year-old youths from 1968 to 1979. Mailed questionnaires were completed and returned for sample sizes ranging from 729 in 1979 to 1,027 in 1969. Although the percentage ever-using alcohol remained virtually stable during the study period, cannabis use fluctuated with an increase from 5.3 per cent in 1968 to 18.8 per cent in 1972, a drop to 16.5 per cent in 1976 to a further rise to 22.5 per cent in 1979. No significant change occurred in the average consumption per drinking situation between 1973 and 1976. However, the average annual consumption of alcohol increased from 1973 to 1974, remained about the same from 1974 to 1975 and decreased significantly from 1975 to 1976. It then increased, reaching the 1974 high level by 1978 and again tapered off by 1979. This pattern was produced by a decreasing consumption among boys accompanied by a steady then fluctuating increase among girls. The average age of first use decreased and boys continued to have their first drink before girls, although to a significantly lesser extent than previously. While boys were found to be drinking less often in 1976 than in 1972, the pattern for girls was the same in 1976 as it was in 1972. Differences by sex declined for cannabis use. In fact, in 1975 and 1976 there was virtually no difference reported in the proportion of boys and girls who had ever used cannabis. Moreover, in 1976, the average age at first use was lower for girls than boys.

A second Norwegian study presented three series of surveys of alcohol use (Brun-Gulbrandsen [ 7] ):

  1. From an adult survey conducted in 1956, 1962, 1966 and 1973, data on all 18- to 20-year-olds were abstracted to produce a sample ranging in size from 107 to 167;

  2. A survey of 15- to 19-year-old youths was conducted in 1971, 1973 and 1975 with sample sizes of approximately 2,000;

  3. A third series was first conducted for Oslo youths in 1960. Questions were asked of 202 14-year-olds, 165 16-year-olds and 135 18-year-olds. The youths who were 14 years old in 1960 were again questioned in 1964 along with a separate group of 190 18-year-olds not previously questioned.

An increasing trend in those ever-using alcohol in the last year was reported between 1956 (69 percent) and 1973 (93 percent). Between 1971 and 1975 no significant increase was found in those reporting they had ever used alcohol, with the exception of 18- and 19-year-olds. A very significant increase was revealed for the average annual frequency between 1962 and 1973 with the greatest increase since 1966. Again, there was no real change between 1971 and 1975 but the 18- and 19-year-olds were shown to be drinking slightly more often. The average consumption per drinking situation did increase between 1971 and 1975, particularly since 1973, and the average annual consumption also increased.

Although the three survey series presented above were not directly comparable, there was a general increasing trend in alcohol use between 1956 and 1975, and certainly the findings reported for the period 1971 to 1975 were corroborated for the most part by Irgens-Jensen and others [ 12] .

4. Sweden

Two Swedish trend studies are discussed here (Hofsten [ 11] ; Hibell [ 10] ). Sune V. Hofsten conducted a series of three studies in 1956, 1961 and 1967. A sample of 1,435 students was compiled from 1,101 classrooms in 201 public high schools. Two separate questionnaire forms were distributed, every other school being sent a different one. Using only one of the two different forms returned, one out of every ten made up the sample.

Significant increases were reported for the consumption and regular use of alcohol with the exception of one type of beer (Class IIA - a light beer, 2.8 per cent alcohol by weight) where a decrease was found. The number of adult abstainers in students' families decreased from 42 per cent in 1956 to 31 per cent in 1967, and attitudes towards alcohol policies followed a liberalizing trend.

In the second Swedish study (Hibell [ 10] ), a number of survey series were presented covering the period from 1947 to 1976. Two of these were conducted

A review of trends in alcohol and cannabis use among young people 87 since 1968. Questionnaires were mailed to 15- to 25-year-olds in 1968 and 1972. Many of the 19- to 25-year-olds in 1972 were involved in the 1968 survey. Approximately 1,600 youths replied in each of the two study years. In the second series, questionnaires were distributed annually for six years (1971-1976) to students of 13 and 16 years of age, from randomly selected school districts. Sample sizes ranged from 8,300 to 13,400 over the study period.

Increases in alcohol consumption were revealed for each study year with 15- to 17-year-old girls showing a continued increase in the proportion of consumers from 1968 to 1972. However, in large cities between 1971 and 1976, decreases were reported among the proportion for high yearly consumers. The age of first use decreased from 1968 to 1972 and the number of times large quantities per occasion were consumed increased. This latter trend continued for the most part between 1971 and 1976 though the general alcohol habits of 16-year-old students changed very little.

In the four Scandinavian countries discussed here there seem to have been increases in the alcohol habits of young people through the 1960s and early 1970s. These increases have fallen off and decreasing trends have even been demonstrated in the middle and late 1970s. An interesting change involved the reported decrease in the difference between the sexes. In fact, in some subgroups, the level of use was the same for both sexes.

Trend studies in Mexico

Only one short-term study was obtained (Castro [ 8] ) and data were made available only for alcohol use. The study involved a national sample of students between 14 and 18 years. Very large increases were found in alcohol use between 1976 and 1978 with 3.5 times as many reporting that they were drinkers in 1978 as in 1976. The rate of increase was greater among females than males. It should be noted, however, that the rate of abstention is high in Mexico, much higher than in any other country with trend data available.

Summary and conclusions

Available trend studies were few in number and varied considerably in their sampling methods. None covered exactly the same periods of time or asked identical questions. Although these studies came from widely separated areas of the world, all save one were from highly developed countries. There were no trend studies available from very poor countries or from those with long traditions of cannabis use. For these reasons only limited trends could be discerned and they should be cautiously interpreted. Available data suggested the following conclusions:

  1. Virtually all countries with trend studies found increases in the proportions of young drinkers and frequent drinkers from the 1960s to the mid to late 1970s;

  2. Many countries have found that the rate of increase of drinking slowed down or stopped altogether in the mid 1970s (Finland, Norway, Sweden) or late 1970s (Canada, United States);

  3. All four countries reporting data on cannabis showed remarkable increases in rates of use (by factors of 3 to 5) from the late 1960s to the late 1970s. Three countries (Canada, Norway and United States) showed a sizeable though less spectacular increase in rate of use in the late 1970s compared to earlier increases;

  4. The factors selected to predict alcohol and cannabis use were not similar enough to make many conclusions other than that males were greater users than females and that age differences tended to show greater use by older students.

The conclusions justify the observation that young persons are becoming slightly more cautious and conservative where drugs are concerned. Many possible explanations can be offered for this phenomenon, among them:

  1. The hazards of cannabis use are becoming more widely recognized. Johnston and others [ 15] found support for this in the United States and it may also be true for other countries;

  2. Per capita alcohol consumption for several countries has stabilized or actually decreased for many Western countries since 1975 -1976. Data are available from Canada, Finland and Norway to support this statement (Addiction Research Foundation (ARF) [ 1] , Ahlstrom-Laakso [ 2] , Irgens-Jensen and others [ 12] );

  3. Rates of alcohol use have reached a peak in many countries which cannot be easily exceeded (80 to 90 per cent) because the remaining abstainers have strong religious beliefs or illnesses which prohibit drinking. During the 1960s young abstainers probably more often lacked access to alcoholic beverages because of restrictive age laws and financial reasons.

In general, this review gives indications that in the near future rates of both alcohol and cannabis use by youths under 21 years of age should stop increasing although actual reductions in numbers of users or amounts used cannot be foreseen.

Acknowledgement

The authors acknowledge the help of Ivar Klausen in making translations into English of some of the studies from Scandinavia.

000

Unpublished comparisons of two studies by M. E. Castro and M. Valencia ( 1976 and 1978).

There must be some non-reporting of sex.

References

001

Addiction Research Foundation. Statistical supplement to the annual report 1978- 1979. Toronto, 1980.

002

Ahlstrom-Laakso, S. Trends in drinking habits among Finnish youth from the beginning of the 1960s to the late 1970s. The State Alcohol Monopoly, Social Research Institute of Alcohol Studies, Helsinki, September 1979. (Reports from the Social Research Institute of Alcohol Studies, No. 128)

003

Alcohol and drug use among Ontario students in 1979 and changes from 1977: preliminary findings. By R. G. Smart and others . Toronto, Addiction Research Foundation, 1979. (Substudy No. 1070)

004

Bell, D. S., R. A. Champion and A.J.E. Rowe. Monitoring drug use in New South Wales: 1971 to 1973. Sydney, Health Commission of New South Wales, 1975.

005

Blackford, L. Summary report-surveys of student drug use. San Mateo, California, Department of Public Health and Welfare, 1977.

006

Blumberg, H. H. Surveys of drug use among young people. International journal of the addictions (New York), 10:699-720, 1975.

007

Brun-Gulbrandsen, S. Forandringer i den norske ungdomens alkoholvaner. In Ungdom och alkohol i norden-utvecklingen i fem lander. Lund, Doxa, 1978, 59-72.

008

Castro, M, E. Personal communication, 1980. Data from 1976 and 1978 surveys. In M. E. Castro and Z. Chao. Reporte interno de la investigación nacional sobre el consumo de fármacos y la actitudes hacia la farmacodependencia en la población escolar de 14 a 18 años. México, CEMEF, 1976 (Reporte Interno) and M. E. Castro and M. Valencia. Consumo de drogas en la población escolar de la ciudad de México y zona metropolitana, correlatos demográficos y la distribución de los usuarios. México, CEMESAM, 1979 (Reporte Interno).

009

Champion, R. A., G. J. Egger and P. Trebilco. Monitoring drug and alcohol use and attitudes among school students in New South Wales: 1977 results. Australian journal of alcohol and drug dependence , 5:2: 59-64, 1978.

010

Hibell, B. Om utvecklingen av den Svenska ungdomens alkoholvaner fran 1947 till 1976. Lund, Doxa, 1977.

011

Hofsten, S. V. Gymnasisterna och alkoholen. Alkoholfragan (Stockholm), 5:151-165, 1969.

012

lrgens-Jensen, O. and M. G. Rud. Bruk av stoffer, alkohol og tobakk blant gutter og jenter i Oslo 1968- 1976. Oslo, Universitetsforlaget, 1977.

013

------------- Changes in the use of drugs, alcohol and tobacco among Norwegian youth year by year from 1968 through 1979. Oslo, National Institute for Alcohol Research, 1979. (SIFA Mimeograph No. 27)

014

Jessor, R. Marijuana: a review of recent psychosocial research. In Handbook on Drug Abuse. Washington, D. C., Government Printing Office, 1978.

015

Johnston, L. D., J. G. Bachman and P. M. O'Malley. Drugs and the class of '78: behaviours, attitudes and recent national trends. Rockville, Maryland, Department of Health, Education and Welfare, Public Health Service, Alcohol, Drug Abuse and Mental Health Administration, NIDA, 1979.

016

------------- 1979 Highlights: drugs and the nation's high school students-Five year national trends. Rockville, Maryland, Department of Health, Education and Welfare, Public Health Service, Alcohol, Drug Abuse and Mental Health Administration, NIDA, 1979.

090

Bulletin on Narcotics. Vol. XXXIII, No. 4-1981

017

Mercer, G. W. and R. G. Smart. The epidemiology of psychoactive and hallucinogenic drug use. In Research advances in alcohol and drug problems, vol. 1. New York, Wiley, 1974.

018

Morris, J. N. Uses of epidemiology. Edinburgh, Livingstone, 1964.

019

Sindballe, A. M. Udviklingen i den danske ungdoms alkoholvaner. In Ungdom och alkohol i norden - utvecklingen i fern lander. Lund, Doxa, 1978, 9-28.

020

Smart, R. G. and D. Fejer. Six years of cross-sectional surveys of student drug use in Toronto. Bulletin on narcotics (United Nations publication), 27:2:11 - 22, 1975.

021

Sulkunen, P. Drinking patterns and the level of alcohol consumption: an international overview. In Research advances in alcohol and drug problems, vol. 3. New York, Wiley, 1976.

022

United Nations Commission on Narcotic Drugs. Review of the illicit traffic in narcotic drugs and psychotropic substances during 1975; part two: statistical tables of drugs seized. 1976. (E/CN.7/591 (Part two))

023

------------- Review of the illicit traffic in narcotic drugs and psychotropic substances during 1978; part two: statistical tables of drugs seized. 1979. (E/CN.7/641 (Part two))

024

Whitehead, P. C., R. G. Smart and L. La Forest. Multiple drug use among marihuana smokers in eastern Canada. International journal of the addictions (New York), 1: 179-190, 1972.