Schaffer Library of Drug Policy

Marihuana: A Signal of Misunderstanding

Investigations of Very Heavy, Very Long-Term Cannabis Users - Jamaica

US National Commission on Marihuana and Drug Abuse

Table of Contents
I. Marihuana and the Problem of Marihuana
Origins of the Marihuana Problem
The Need for Perspective
Formulating Marihuana Policy
The Report
II. Marihuana Use and Its Effects
The Marihuana User
Profiles of Users
Becoming a Marihuana User
Becoming a Multidrug User
Effects of Marihuana on the User
Effects Related to Pattern Use
Immediate Drug Effects
ShortTerm Effects
Long Term Effects
Very Long Term Effects
III. Social Impact of Marihuana Use
IV. Social Response to Marihuana Use
V. Marihuana and Social Policy
Drugs in a Free Society
A Social Control Policy for Marihuana
Implementing the Discouragement Policy
A Final Comment
Ancillary Recommendations
Legal and Law Enforcement Recommendations
Medical Recommendations
Other Recommendations
Letter of Transmittal
Members and Staff
History of Marihuana Use: Medical and Intoxicant
II. Biological Effects of Marihuana
Botanical and Chemical Considerations
Factors Influencing Psychopharmacological Effect
Acute Effects of Marihuana (Delta 9 THC)
Effects of Short-Term or Subacute Use
Effects of Long-Term Cannabis Use
Investigations of Very Heavy Very Long-Term Cannabis Users
III. Marihuana and Public Safety
Marihuana and Crime
Marihuana and Driving
Marihuana - Public Health and Welfare
Assessment of Perceived Risks
Preventive Public Health Concerns
Marihuana and the Dominant Social Order
The World of Youth
Why Society Feels Threatened
The Changing Social Scene
Problems in Assessing the Effects of Marihuana
Marihuana and Violence
Marihuana and (Non-Violent) Crime
Summary and Conclusions: Marihuana and Crime
Marihuana and Driving
History of Marihuana Legislation
History of Alcohol Prohibition
History of Tobacco Regulation
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National Commission on Marihuana and Drug Abuse

Investigations of Very Heavy, Very Long-Term Cannabis Users


Another foreign investigation (Ruben et al., 1972) conducted in Jamaica (under contract for the National Institute of Mental Health) studied chronic cannabis users and matched nonuser controls. Preliminary findings have shown little evidence of significant differences between the two groups in the extensive anthropological, medical, psychiatric and psychological investigations.

Ganja use is widespread and endemic in the Jamaican lowest socioeconomic strata, and in particular in a millenial-religious sect known as the Rastafarians. More than 50% of all male Jamaicans are estimated to use some form of cannabis, and probably about 20% are regular heavy users of ganja.

The drug was brought to Jamaica from India over 130 years ago by indentured East Indian laborers. However, presently the heaviest ganja users are Afro-Jamaicans who comprise 90% of the population.

The Rastafarian religious sect, founded by Marcus Garvey, preach a "Back to Africa" destiny and claim Haile Selassie to be God. The Rastafarians have always worn. long hair and beards and dressed eccentrically. They believe that "the herb" was given them by God to help them to understand his wisdom exemplified in their greeting, "Peace and Love."

The Rastas reject the values of the dominant society and regard the government as "the powers of Babylon". They have, chosen to opt out of conventional society and instead work and live in a communal existence in poverty. They emphasize the value of ganja in achieving a new level of meaning in this existence.

The Rastafarians add ganja to their infant first bath and start feeding the drug to their infants from the time of weaning in an infusion known as ganja tea. They continue to smoke and drink the drug throughout life.

They, like many other Jamaicans, believe in its medicinal properties especially for asthma and indigestion and promotion of healing; that it gives protection from evil spirits; that it cleanses the skin and purifies the blood; that it promotes sexual vigor; that it gives energy for work and relieves fatigue and provides relaxation after work.

Extensive in-depth studies have been carried out by a team of anthropologists from The Research Institute for the Study of Man in conjunction with The Departments of Psychiatry, Pathology, Physiology and Medicine, of the University of the West Indies. Anthropology field workers lived for extensive periods of time in five rural communities (including fishing, farming and cane cutting areas) and two urban districts.

Over 2,000 people were observed and studied in these communities. Overall life styles of the ganja users were not notably different from nonusing individuals in the Jamaican lowest socioeconomic strata. Users are working, maintaining stable families and homes, and actively participating in their society. No evidence was noted of crime or aggressive behavior or drug use other than alcohol related to ganja use. No evidence of physical dependence was demonstrated. Minimal psychological dependence was observed but no drug craving was expressed.

Thirty long-term ganja smokers and 30 nonusers matched demographically to control factors other than ganja use, were chosen as representative of this functioning lower socioeconomic population and selected for intensive hospital study in order to determine, differences between the two groups.

The mean age of the subjects was 33 with a range of 23 to 51. The primary occupation of one-third of the subjects was farming. The next most common occupations were, fishing, skilled and semiskilled laborers. Half practiced no formal religion, five were Rastafarians and the remainder practiced a wide variety of traditional religious. Almost three-fourths of the males had stable "marriages" and the remaining single subjects were predominantly the younger ones.

The subjects were divided into three groups. Twenty-three were nonganja smokers, 28 were regular daily ganja smokers and 9 were occasional ganja smokers using the drug several times a we or less. Three types of regular ganja smokers were delineated: light smokers using one to four spliffs daily moderate smokers using four to seven spliffs daily; and heavy smokers using eight or more spliffs per day.

Age of first use ranged from 8-36 years of age. Regular use of ganja occurred at a median age of 16 years with a range of 9-25 years. All ganja smokers had used the drug at least 7 years and some up to 37 years with a mean of 17.5 years.

The ganja users consumer on the average seven spliffs of ganja daily with a range of one to 24 per day. The typical ganja cigarette or cigar, termed a spliff is roughly a four-inch-long paper cone and contains about two to three grams of ganja with a delta 9 THC content of about 2.9% on the average (range of 0.7-10.3%) mixed with about half of a Tobacco cigarette. Also many smoke ganja in a Chillum pipe using very deep inhalation to fill their lungs with smoke. They consume 14 pipe fulls per week on the average, with a range of 1-25 per week.

No significant differences in neurological abnormalities, electroencephalographic abnormalities, hemochemical changes including liver function, urinalysis, chest X-ray abnormalities or chromosome damage in lymphocytes were found in the users or controls.

One user had a long history of bronchial asthma and another had a mild case of Jamaican neuropathy, but nothing suggests these disabilities were in any way related to ganja use. Minor electrocardiographic abnormalities were present in about one-third of both users and controls. This may be related to a syndrome of unknown etiology known as Jamaican cardiomiyopathy.

Thorough physical examination and hematological studies revealed only minimal significant differences between ganja smokers and non-ganja smoking controls. Comprehensive evaluation of red blood cell indices revealed that the ganja smokers had significantly higher hemoglobin levels and packed red cell volumes (hematocrit) than the non-ganja smokers.

These hematologic findings are compatible with those reported recently (Sangan and Balberzak, 1971) for heavy tobacco cigarette smokers. The authors noted that cigarette smoking causes a functional tissue hypoxia due to deficits in lung func tionwith resultant arterial oxygen unsaturation. Thus, an increased demand is placed on the bone marrow to provide more red blood cells to increase the oxygen carrying capacity of the blood.

In addition to the heavy smoking of ganja in spliffs and pipes, 27 of the 30 ganja smokers were tobacco smokers, and several have smoked tobacco cigarettes heavily. 19 of the 30 non-ganja smokers were tobacco cigarette smokers and tended to be light tobacco cigarette smokers.

Thus, the data appears to suggest that a combination of factors including number of years and quantity of cigarette smoking, ganja spliff smoking and ganja chilum pipe smoking is significantly correlated with the hematological changes indicative of functional hypoxia. However, pulmonary function studies did not demonstrate significant decrements correlated with ganja or tobacco smoking.

No significant differences were found between groups by a thorough psychiatric and psychological examination. All subjects were judged to be in normal mental health. Subjects were administered a battery of standardized reliable American psychological tests known to be sensitive to impairment in brain function. These tests were not culture free so that comparison of performance, between Jamaicans and Americans is meaningless Nineteen tests evaluating 47 variables were performed including one personality test, three tests of intelligence and verbal abilities, and 15 neuropsychological tests.

Two of 47 variables had statistically significant differences between ganja smokers and non-smokers. The smokers scored higher on the digit span subtest of the Wechsler Adult Intelligence Scale and bad a more centralized personality organization on the Lowenfeld Mosaic Test.

Non-smokers had the best performance on the number of edge contacts with the non-dominant hand on the Holes Test. These few significant differences were considered chance findings by the investigators.

In general no consistent differences were found on these psychological tests between ganja smokers and non-smokers. The data clearly indicate that the long-term ganja use by these men did not produce demonstrable intellectual or ability deficits when they were without the drug for three days. No evidence in these results suggest permanent brain damage.

The alleged role of ganja in producing personality change in the direction of a loss of competitive striving and an unwillingness to work, termed the amotivational syndrome was also investigated.

Based on clinical impressions gained from careful sociological and psychological techniques, the investigators noted that the chronic ganja smoker differed little in work habits or record from his matched control. No evidence of an amotivational syndrome was found. In fact, the subjects believe ganja has a functional value as a work adjunct. It provides energy for work and helps them do arduous boring jobs.

In the Jamaican culture, ganja may produce a "motivational syndrome". In an objective videotape evaluation of work energy output and ganja smoking, ganja use did not lower productivity on simple repetitive tasks, such as woodcutting which requires compulsive concentrated effort.

A study of cultivators points up the relationship of population, land, and economic pressures to ganja use. In the area studied land resources are scarce, farms small and cultivation difficult on the hilly slopes. Market conditions determine income from cash crops and restrictions on migration maintain population pressures on limited resources.

For these farmers, the researchers suggest that ganja use, decreases total cultivated acreage and consolidates production while disruption of competition and social cohesiveness among the farmers is avoided.

These data may indicate that heavy ganja use during cultivation in farming situations with limited alternatives may serve to maintain the status quo. However, it is possible that the compulsive concentrated effort experienced by the cultivators with heavy ganja use may be productive in areas with good soil and climatic conditions where systematic weeding can increase crop yields.

As a result of the extensive anthropological study, the investigators believe that ganja use in Jamaica is a culturally determined phenomenon. A "ganja complex" exists which consists of closely related, learned patterns of behavior manifested by the members of the society.

The ganja complex appears to be functional for the working-class Jamaican. Various elements Of the complex including economic, social and personal are interrelated in ways that contribute to operation of the whole culture.

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