Does Cannabis Abuse Represent a Gateway to Harder Drugs?

The question of whether cannabis represents a gateway to harder drugs has occupied clinicians and researchers for 30 years. The reason for the interest in this question has been that a transition to harder drugs – heroin, amphetamines or cocaine – represents a significant increase in the degree of risk to which the individual is exposed. Even though cannabis is more psychotoxic than heroin, intravenous heroin abuse is in many other respects a considerably more serious condition than cannabis dependence. With heroin – which is also much more expensive than cannabis –, addiction not infrequently develops quickly, the dependence is strong, and mortality is considerably higher, mainly owing to overdoses. It is the rule rather than the exception that heroin-dependent individuals become socially marginalised. The abuse of both amphetamines and cocaine (not least in the form of “crack”) also leads to rapid development of severe dependence, with the risk of a series of mental side-effects and high mortality levels. Moreover, transition to intravenous abuse adds the risk of HIV infection. The most extensive studies in this field have been carried out by Denise Kandel and her research team. They showed, at an early Read more […]

Cocaine: Longitudinal study of users (1975-1983)

Methods A total of 118 cocaine users were recruited for study in 1974. Of these, 19 were selected for interview and questionnaire study while 99 (85 males, 14 females) were selected for a more comprehensive longitudinal study. All 99 users (18-38 years old) were social-recreational users who met the initial requirement of having used a minimum of 1 gram of cocaine per month for 12 months (range 1-4 grams). The majority of users were students (73 percent,) while others listed their occupations as housewives, business people, writers, attorneys, physicians, secretaries, teachers, or unemployed. Exaninations and tests were performed on each subject at 6-month intervals for 4 years (1975, 1976, 1977, 1978) and then at approximately 18-month intervals for another 5 years. Examination procedures included a personal history questionnaire, drug history questionnaire, subjective drug effects questionnaire, mental status exanination, the Minnesota Multiphasic Personality Inventory (MMPI), the Experiential World Inventory (EWI), in-depth interviews, and physical examinations (for most subjects). In addition, assays were performed on samples of cocaine used by these subjects. An important caveat is that a number of users dropped Read more […]

Multiple Drug Use Epidemiology, Correlates, and Consequences

The initial focus is on the conceptual issues essential to the understanding of multiple drug use. This is followed by a discussion of the developmental nature of multiple drug use and the various strategies that have been designed to measure multiple use. The third section of the paper contains a review of the extent of multiple drug use in various segments of society with data from the Monitoring-the-Future surveys of high school seniors, the National Survey on Drug Abuse, and the Treatment Outcome Prospective Study of drug abuse treatment clients. The conclusion is that multiple drug use is pervasive. The next section deals with several consequences associated with multiple drug use: automobile accidents, delinquency, and emergency room visits. The final section outlines some of the prevention and treatment implications of multiple drug use from a public policy perspective. In a study of the effects of a single drug upon behavior, the implications are manifold. Dosage levels, modes of administration, baseline states, the expectations of the subjects and of the investigators, the environment in which the drug is taken — all these variables, and others as well, make human psychochemical studies difficult and complex. Read more […]

Consequences of Multiple Drug Use: Specifying the Causes

In order to illustrate these points, three specific consequences of drug use will be discussed in some detail below. These three consequences are traffic accidents, involvement in delinquent/criminal acts by youth and young adults, and emergency room visits related to drug abuse. Traffic Accidents The Monitoring-the-Future surveys contain several questions concerning traffic accidents. The seniors are first asked how many accidents (i.e., a collision involving property damage or personal injury — not bumps or scratches in parking lots) they had while they were driving in the past 12 months. If the answer is one or more, the senior is asked how many occurred after he/she was drinking alcoholic beverages and then how many occurred after he/she was smoking marijuana or hashish. By piecing together the information from these separate questions, it is possible to estimate the proportion that would be due to alcohol, to marijuana, and to alcohol and marijuana. The data in Table “Motor Vehicle Accidents and Their Connection to Use of Alcohol, Use of Marijuana, and Use of Both Alcohol and Marijuana” are for seniors in the class of 1980 classified according to the extent of alcohol and marijuana use reported during the Read more […]

The Epidemiology of Multiple Drug Use

How much multiple drug use is there? What proportion of the population at any one point in time is using/abusing multiple substances? Has use of multiple substances become more normative in the recent past as opposed to exclusive use of a favorite drug? What are the principal consequences of multiple drug use? Do these consequences differ according to pharmacological parameters for interactive potential or are there other parameters of almost equal predictive value? To what extent are the consequences attributed to single drugs (traffic accidents labeled as alcohol related) really the result of impaired judgment and performance from ingestion of multiple substances? These are just a few of the questions that need to be addressed within the scientific and public policy communities. In the following section some epidemiological data pertinent to understanding the “extent” of multiple drug use are presented. Monitoring-the-Future Studies Each year since 1975, researchers at the Institute for Social Research at the University of Michigan have administered questionnaires to about 17,000 high school seniors attending schools randomly chosen to be representative of all high schools in the continental United States. These Read more […]

Measuring the Developmental Nature of Multiple Drug Use

There have been a number of studies in which attempts have been made to measure or assess multiple drug use. Some of these are from general populations while others are focused on specific subpopulations of users. The studies are grouped more on the basis of the approach taken to assessing multiple drug use than on the patterns uncovered. There are at least four different groupings of studies and some studies fit into more than one grouping. Developmental Patterns of Onset of Use One of the most influential attempts to describe patterns of multiple drug use is the “stages of drug use” model developed by Kandel. Kandel posited that persons proceed from licit to illicit drugs and from use of less to more serious drugs. The stages of drug use involvement that she identified were: (1) no use of any drugs; (2) use of beer or wine; (3) use of cigarettes and/or hard liquor; (4) use of marijuana; and (5) use of illicit drugs other than marijuana. Although it is not made explicit by Kandel, there is an implication that the drugs from the earlier stages of development are “carried forward” into the later stages of drug involvement. Thus, a marijuana user is likely to continue his or her use of cigarettes/hard liquor and beer Read more […]

Internal Stimulus Control and Subjective Effects of Drugs

For many years psychotropic drugs have been characterized and classified using methods designed to measure their subjective effects in humans (). This research approach has two principal purposes: 1) to investigate the efficacy of a drug in attenuating unwanted subjective states in patients (e.g., pain, anxiety, depression), 2) to investigate the abuse potential of new drugs by comparing their subjective effects in experienced drug abusers to those produced by known drugs of abuse. In regard to the latter, such methods have been used to determine whether there are any common subjective states produced by all drugs of abuse (e.g., euphoria). Systematic studies of subjective methods for drug classification have been conducted at the Addiction Research Center (ARC) in Lexington, Kentucky, now part of the National Institute on Drug Abuse. A major mission of the ARC has been to evaluate new analgesic compounds to determine whether they produced morphine-like effects. The subjective effects of morphine and related compounds were an important aspect of this evaluation. The research demonstrated that morphine and related narcotic analgesics produced a unique spectrum of subjective effects that can be reliably discriminated Read more […]

Usefulness of Propoxyphene Napsylate for Maintenance Treatment of Narcotic Addiction

Recently several studies have examined the use of propoxyphene napsylate (Darvon-N) in the detoxification and maintenance of narcotic addicts. Tennant () reported that three programs in Los Angeles had succeeded in detoxifying 280 heroin addicts with propoxyphene napsylate, while maintaining 92 others on an outpatient basis for periods up to 240 days. In a doubleblind detoxification study comparing propoxyphene napsylate and methadone, he found that propoxyphene patients were more likely than methadone patients to be opiate abstinent at one month followup (). However, in this doubleblind study, Tennant found propoxyphene to be less effective than methadone in suppressing withdrawal complaints. He also noted side effects from propoxyphene, such as mild visual hallucinations, slurring of speech and seizurelike symptoms (). Jasinski () reported that propoxyphene napsylate used in maximum non toxic doses (about 1200 mg per day) produced narcotic-like activity equal to that of only 20 to 25 mg of subcutaneously administered morphine, or 10 mg of orally administered methadone. Again, he found that propoxyphene napsylate doses greater than 700 mg produced disturbing side effects in many subjects. This paper will report Read more […]

Consequences of Prenatal Drug Exposure: Opiates

Epidemiology of Opiate Use in Pregnancy The literature regarding developmental outcomes for infants prenatally exposed to opiates is relatively sparse and was primarily generated in the 1970s and early 1980s. The literature is also made more problematic by the issue of polysubstance abuse, as research investigating prenatal opiate exposure includes exposure to heroin, methadone, or both, and may also include exposure to amphetamines, barbiturates, benzodiazepines, cocaine, alcohol, and nicotine. Recent studies report prevalence for opiate use during pregnancy to range from less than 1 to 2 percent to as high as 21 percent. Growth/Physiological Effects The most consistently reported effect of prenatal opiate exposure is associated with fetal growth retardation and neonatal abstinence syndrome. Neonatal abstinence is described by Kaltenbach and Finnegan () as a generalized disorder characterized by signs and symptoms of central nervous system hyperirritability, gastrointestinal dysfunction, respiratory distress, and vague autonomic symptoms that include yawning, sneezing, mottling, and fever. These early neurobehavioral outcomes do not persist, however. Within the past decade, methadone maintenance has become accepted Read more […]

Medical Consequences of the Use of Cocaine and Other Stimulants

Once thought to be a benign, nonaddicting drug, cocaine now has well-recognized adverse effects. These adverse effects are manifested in nearly all organ systems of the body. It is important to realize that an organ system breakdown in classifying the adverse effects of cocaine is artificial and that multiple organs are often affected by similar mechanisms. In particular, the effects of cocaine on the cardiovascular system help to explain many of the effects on other organs throughout the body. In addition, certain adverse effects may be dependent on the route of administration, or dose of cocaine. The adverse effects of two other stimulant drugs, methamphetamine and phenylpropanolamine, will be summarized at the end of this post. History The history of cocaine use has been well described by a number of authors. Peruvian Indians have a long history of chewing coca leaves to achieve euphoria, combat fatigue, and increase stamina. Sigmund Freud used cocaine and also prescribed it as treatment for alcohol or opiate addiction. At one time, cocaine was a common ingredient in many commercial products, including teas and patent medicines. Although no longer the case, when first introduced, Coca-Cola was formulated using Read more […]