effects has led to much confusion. Attempts to classify drugs of abuse are fraught with difficulty.
One simple method to classify drugs would be to group them according to whether or not the substance is legal. Some substances are legal with unrestricted access (for example, caffeine), while others are legal, but have certain restrictions on their availability (alcohol and nicotine, for instance, although legal are not available to those under the age of 18, while certain medications are only available on prescription from a healthcare professional). Finally, many other substances are clearly illegal (for example, cocaine, heroin and amphetamines).
Such a classification system may provide superficial clarity. It is, however, not necessarily always accurate. For instance, the legal boundaries differ from country to country. An example of this is cannabis, which is legally sanctioned in some countries but illegal in others. The same applies to alcohol, which is generally freely for sale to adults in Western countries, but restricted in most Middle Eastern states. Codeine and other medications are readily available at pharmacies in many countries, yet could get you arrested in others because they are highly scheduled and controlled drugs.
A second method of classifying drugs of abuse is to use the chemical composition of the substance as the primary determinant in the classification system. This is a useful classification system for pharmacologists, but tends to be impractical and cumbersome for everyone else. Chemical theories and chemical names are difficult to understand and complex to use in practice for those without a background in chemistry. Does it really matter that ecstasy is classified as 3.4-methylenedioxy-N-methamphetamine (MDMA)? We are probably also not interested to know that it is related to 1-(3.4-methylene-dioxyphenyl)-2-aminopropane (MDA). Both of these drugs are in a very different chemical category to heroin (an opioid agonist) and delta-9-tetrahydrocannabinol (cannabis). Such chemical names and classifications are clearly too confusing for those who do not work with these substances in a laboratory setting.
A third method of classifying drugs could be according to their ingestion route, namely oral, injected, snorted/sniffed nasally, or smoked/inhaled. This, too, is an unsatisfactory classification system. Alcohol is mostly consumed orally by drinking, while other drugs can be ingested by various routes. Although heroin is injected or smoked/inhaled, this is not in the same way that cigarettes are smoked, but rather by inhaling the fumes when heroin is heated in a particular way. This is called “chasing the dragon”, due to the curling of the smoke resembling a dragon’s tail. Cocaine and amphetamines can be injected, smoked and snorted. Various prescription medications are taken orally in tablet or capsule form, but are also often crushed and either snorted or injected.
After years of studying medicine, specialising in psychiatry and subsequently working within the substance use field, I have developed a classification system that I find practical and easy to understand. I use this system to teach substance users, their families and medical students about drugs of abuse. The classification system is related to the terms used by drug users themselves. These terms are “uppers”, “downers” and “psychedelics”. These three categories lend themselves to a simple approach to the classification of drugs. All drugs of abuse can now be classified into five large groups, namely:
1 Uppers, also generally known as stimulants.
2 Downers, also generally known as depressants, sedatives or hypnotics.
3 Psychedelics, often referred to as hallucinogens or psychomimetics.
4 Other drugs of abuse that don’t fit neatly into any of the above three categories.
5 Drugs that overlap categories.
Over the years I have encountered other texts that use a similar classification system. This system is therefore a hybrid of my own ideas, as well as the broadly accepted categories of various drugs of abuse. Some academics may argue that many drugs of abuse should be in a different category. Their reasons are varied, but are mostly based on the chemical composition or clinical effects of a substance. They are not necessarily wrong. Such different opinions simply illustrate the difficulty in trying to explain a complex situation in a simple manner. It is for this reason that I have added the fifth category for drugs which could overlap the first three categories. This fifth group of drugs could be included in more than one category due to their different chemical composition or different clinical effects.
Uppers or stimulants
Most central nervous system stimulants influence a brain chemical called dopamine.
Classic stimulants
The classic stimulants include amphetamine and cocaine. Common names for amphetamines include methamphetamine, crystalmethamphetamine, crystal meth, speed, tik or ice. Common names used to refer to cocaine include coke, crack, candy, rock, snow and flake. The smokable forms of amphetamine (tik, ice) and cocaine (crack) are highly concentrated and refined and hence also highly addictive.
Other stimulants
Other stimulants include cathinone (khat, cat), ecstasy (XTC, E, Adam, X, MDMA), PMA (doctor death), caffeine (coffee), nicotine (cigarettes, tobacco) and certain medications that are only available at pharmacies with a prescription from a doctor. Such medications include ephedrine and pseudoephedrine containing products and methylphenidate (Ritalin). Over-the-counter medications include certain anti-obesity, and cold and flu products.
Downers or depressants
Most central nervous system depressants affect a chemical in the brain called GABA or the opioid system.
Classic depressants
Classic central nervous system depressants include alcohol (ethanol), opiates (heroin) and opioids (synthetic prescription medications). Common names for heroin include smack, brown sugar, Thai white, China white, horse or H. Other classic central nervous system depressants include sedatives and hypnotic medication, such as the benzodiazepine group and an older group of medication called barbiturates.
Other depressants
Other depressant substances include GHB (gamma hydroxybutyrate or liquid ecstacy); Zopiclone and Zolpidem, which are commonly prescribed sleeping medications; and Methaqualone (mandrax, star, flowers, boggel, Mandies, ludes, Q, vitamin Q, Quaalude). Other medications in this group include meprobamate and chloral hydrate.
Opiates and opioids
Opiates and opioids are terms derived from the word opium, which refers to the poppy plant, also known as Papaver somniferum. Opiates are substances that are either derived or synthesised from the natural opium compound or its various chemical components. Examples include heroin, morphine and codeine. Routine drug screening tests usually detect opiates.
Opioids include all substances that bind on one or more of the opioid receptors in the brain. They resemble opiates, but are not necessarily directly or indirectly derived from the natural poppy plant. They are thus synthetic substances with opiate-like properties. Examples include pethidine and methadone. Routine urine drug screening tests usually require a specific request to detect opioids. Opioids therefore encompass the opiates. These two terms are, however, often used interchangeably.
Hallucinogens or psychedelics
Most hallucinogens affect a brain chemical called serotonin. They can also affect the cholinergic and the cannabinoid brain systems.
Classic hallucinogens
The classic hallucinogens are LSD (lysergic acid diethylamide, candy, blotter, microdots or acid), MDA (Eve, love drug), mescaline (peyote cactus) and psilocybin (magic mushrooms,
