The Reward System of the Brain

The Reward System of the Brain

Several addicts were asked why they take drugs. One reply, “It is one of the most intense, orgasmic, and amazing experiences I’ve ever had.” Another reply, “It is better than the best Saturday night I ever had.”

The effects of drugs can vary according to the drug. Drugs can make us feel good, even wonderful. These drugs are divided into 10 different classes that have different, although not completely distinct, pharmacologic mechanisms. The classes of drugs include¹:

• • Alcohol
  • Caffeine
  • Cannabis and synthetic cannabinoids
  • Hallucinogens (e.g., LSD, phencyclidine, psilocybin, methyl​enedioxy, ​methamphetamine [MDMA])
  • Inhalants [volatile hydrocarbons] (e.g., paint thinner, certain glues)
  • Opioids (e.g., fentanyl, morphine, oxycodone)
  • Sedative, hypnotics, and anxiolytics (e.g., lorazepam, secobarbital)
  • Stimulants (e.g., amphetamines, cocaine)
  • Tobacco
  • Other (e.g., anabolic steroids)

This classification is not based on whether a drug is legal (e.g., alcohol, caffeine), illegal (e.g., hallucinogens), or available by prescription (e.g., morphine, lorazepam).¹

As previously noted, the brain is a very complex organ. Drugs interfere with the way the neurons send, receive, and process signals through the neurotransmitters. Drug addiction may be regarded as the disease of the brain reward system.²

Addictive drugs distort neurotransmission by mimicking or sometimes blocking neurotransmitters in uncontrolled ways. This means the brain itself does not have any mechanism to regulate and control the drugs or what they are doing.

Because abused drugs in the brain are in fact chemical signals, they are like neurotransmitters.³

However, their actions are very different from neurotransmitters. The brain and neurotransmitters have co-evolved over eons of time, and they co-exist.

Drugs of abuse enter the brain and affect neurotransmission, but the brain does not have ways to handle or end the actions of the drugs. Drug levels in the brain are under the control of the drug taker and not regulated. The drugs create utter chaos!

“I used to be able to stop, but now, if I don’t have the stuff, I go crazy. They say it’s in my head, my brain. Somehow, it’s changed…”

This person is correct! The brain has changed.

It bears repeating, drugs act like neurotransmitters, but yet have very different time courses, different regional effects, and different effects at various receptors. All of this happens at the same time! No wonder drugs change the brain and our behavior.