Whether used in social situations or as part of religious ceremonies, people have been using mind-altering substances for as long as there have been people. Alcohol and tobacco remain the drugs of choice for the majority of the population, but they aren't the only drugs on the market. Some of these drugs, such as heroin and cocaine, have been around for a very long time, while others — the “designer drugs” — are relative newcomers.

Marijuana

Marijuana (Cannabis sativa) is the most commonly abused illegal drug in the United States, according to the National Institute on Drug Abuse (NIDA). More than a drug, marijuana is a cultural icon of the counter-cultural and alternative lifestyle. Apart from its association with the peace and love movement, marijuana has properties that make it a plant of interest for the scientific research community, both for its possible benefits as well as its adverse effects on health.

On the positive side, when used as prescribed by a doctor, THC — the abbreviation for delta-9-tetrahydrocannabinol — has been found to be effective for treating nausea and vomiting associated with chemotherapy. Dronabinol (Marinol) is the pharmaceutically manufactured version of THC.

On the negative side, long-term use of marijuana leads to changes in dopamine production, similar to that of other illegal drugs. It's also been implicated in the onset of depressive symptoms. The Harvard Medical School Family Health Guide reported on an Australian study that found that young women who had used marijuana weekly as teenagers were twice as likely to have depression as young adults than those who didn't use marijuana. Daily use of marijuana was associated with four times the risk of depression.

Heroin

Heroin use is on the rise, with an estimated 750,000 current heroin users in the United States. Heroin is processed from morphine, and, just as with alcohol, regular heroin use builds up tolerance to the drug, so that higher doses are required to achieve the same high. The effects of the drug harm the body, and withdrawal symptoms can lead to extreme depression and suicidal behavior.

Cocaine

Heavy cocaine use has remained fairly steady since its peak in the late 1980s and early 1990s, with an estimated 600,000 to 700,000 regular users. A University of Michigan study that appeared in the January 2001 issue of the American Journal of Psychiatry found that cocaine harms dopamine neurotransmitters — specific brain cells associated with the brain's “pleasure center.” Using cocaine can disrupt the dopamine cycle and lead to severe depression.

Ecstasy

Ecstasy is an amphetamine-based drug, originally used in the 1970s to treat depression. It affects the neurotransmitter serotonin. Today it's a party drug used primarily by young adults to allow them to party all night long (rave). The United Nations estimates that its use has risen 70 percent between 1995 and 2000.

Ecstasy may not cause depression, but has been implicated in intensifying depression's symptoms. Dutch researchers began a longitudinal study in 1983 in which they followed a group of children who suffered from depression. Results indicated that children who suffered from depression were more likely to use Ecstasy as adults. The implication is that Ecstasy capitalizes on pre-existing risk factors.

Crystal Meth

Crystal Meth, also known as ice, crystal, glass, jib, speed, and tina, is produced in makeshift labs in garages, basements, and even travel trailers throughout the country. It's a cocktail of ingredients including pseudoephedrine and paint thinner. Meth releases high levels of dopamine, is highly addictive, and can cause severe depression.

How This Relates to Depression

Here's the bottom line: Neurotransmitters are affected by different drugs:

• Dopamine is affected by cocaine, amphetamines, and ecstasy.

• Serotonin is affected by ecstasy and LSD.

• Noradrenaline (Norepinephrine) is affected by amphetamines and the opiates, such as heroin and morphine.

Many people use more than one recreational drug, and sometimes they use more than one drug at the same time. Understanding that these drugs do not get along well together is an important first step on the road to realizing that they don't mix with depression at all. Frequently, if you discontinue your use of these drugs, you will find that the symptoms of depression are greatly relieved.

If you are currently using recreational drugs and want to get out from under depression's thumb, talk with your psychotherapist or family physician to find out the best way to do this. Be honest about your drug use. Quitting cold turkey may seem the logical choice, but turkeys aren't known for their intelligence. Do this the right way, under the supervision of your physician.