Do animals take drugs? Some birds get drunk after eating grape seeds that have fermented. In Africa, baboons that eat the fermented fruit of the marula tree show signs of drunkenness, such as staggering. Hens can get drunk from apple cider, then run around in all directions with their eyes rolled up in their sockets. In the southern United States, after sheep and horses have grazed on astragalus, a plant related to clover, they start to do strange things, like taking huge leaps to clear tiny obstacles, or running around in circles for hours.
In all these cases, however, it is very hard to tell whether the animals are actually ingesting these materials deliberately in order to become intoxicated, or whether that is just an unintended consequence of eating these materials.
There are many reasons that people take
substances that alter their mental state. (Place your cursor over
the name of each substance to see some examples).
In all these cases, taking the drug provides an immediate sense
of pleasure or relief that encourages the person to take it again.
Almost all drugs act as positive-reinforcement
In fact, drugs capitalize on a system that the human species has evolved to reinforce
behaviours favourable to its survival–behaviours such as eating or having
sex, both of which generate pleasure and a sense of well being.
Drug-taking is nothing more than an artificial means of activating this natural
system. The danger with certain drugs is precisely that they short-circuit
this natural pleasure-producing pathway. As a result, to try to forget what
they experience as intolerable realities, people may start to consume substances
abusively, then end up so overwhelmed by their dependencies that
they forget even their most basic needs.
The risk that you run when you consume
drugs is somewhat like the risk that paddlers take when they
approach a giant waterfall. Most of them turn back. Others
try the first few rapids to experience the thrill of a calculated
risk. A still smaller group brave the worst dangers to experience
intense sensations, but still know how to pull out if they
feel themselves losing control. But some people cannot resist
the urge to keep going, and they tumble over the edge.
How long it takes to become “hooked” on
a substance depends on both the individual and the substance.
It can take a fairly long time to become addicted to alcohol,
but very little time to become addicted to other substances,
such as heroin.
Some people become heroin-dependent within as little as
Usually, when we hear the word “dependency”,
we immediately think of dependency on drugs–substances
that people introduce into their bodies. But there is a
second major category of dependency: dependency on a particular
activity. In this case, the molecules that create the dependency
are secreted by our own bodies. The activity may be a sport,
or a game, or being with a particular person, or any other
situation that provides strong sensations.
The term “cravings” is
used to describe the feelings experienced by people who
have dependencies. The word "addiction" comes
from a legal term in Old French that means “indenturement”
–the act of becoming a slave to pay off one’s
Taking a drug for pleasure does not lead inevitably to dependency.
Someone can start to be considered dependent on a particular
psychoactive substance when they display an irresistible, compulsive
need to keep taking it.
Experts have identified several signs of drug dependency. If
someone displays several of them, that is a good indication that
they have become dependent on the drug in question. These signs
a persistent desire for the drug and an inability to stop
the development of a tolerance for the drug that forces them
to keep taking larger doses to achieve the same effects;
the onset of withdrawal symptoms when they cannot obtain
spending a great deal of their time obtaining the drug, consuming
it, and recovering from its effects;
an inability to stop or control their consumption of the
drug, even when it goes against their own values;
continuing to take the drug, even when they recognize the
major physical, psychological, and social problems caused by
In varying degrees, we are all dependent on something, because
dependency is closely related to the pursuit
of pleasure. And we are all predisposed to repeat pleasant
experiences, because this has proven an effective survival strategy
in the evolution of our species.
The problem, then, is to manage our pleasure so that it does
in fact do us more good than harm, because dependencies have physical
and psychological components that help to keep dependent
people in a self-destructive spiral of consumption
are often characterized by periods of abstinence followed
by episodes of recidivism. Such episodes usually occur
when people find themselves back in the circumstances that
were associated with their dependency ritual. Smokers who
have quit know how strongly they can be tempted to smoke
in situations where they used to have a cigarette, such
as after a meal, or in a bar, or when they are trying to
solve a problem. Similarly, former drug addicts who return
to the environment where they used to take drugs run a
higher risk of falling back into their old habits. Dopamine,
a chemical messenger involved in the reward circuit, may
play a very specific role in this environmental