The lasting effects of heavy drug use are well known—addiction, serious health issues, infectious diseases and changes in the way you think are all risks of using frequently. However, using drugs like marijuana or cocaine occasionally can also have negative effects on behavior and overall health—especially for younger people.

“While smoking marijuana or using cocaine every now and then might not seem like big deal, especially to young people, that occasional use can still leave a lasting effect on your brain, heart and lungs,” said Margaret Jarvis, M.D., medical director of Geisinger Marworth Treatment Center in Waverly.

Marijuana is a psychoactive drug, which means that when it’s smoked or ingested, it alters your thinking. THC, the chemical responsible for a high and relaxed feeling, also impairs judgment, coordination and memory. And for some, that same high may also bring feelings of anxiety, depression or paranoia. Using marijuana also typically causes an increased heart rate, lowers your blood pressure and impacts your blood sugar levels.

One study found that the brains of teens who used marijuana even occasionally began to change. Specifically, researchers saw changes in the parts of the brain that control addiction and rewards, as well as the part that controls emotion and helps form long-term memories.

“Using marijuana as little as once a week can cause at least some change in the brain, especially for adolescents and young adults whose brains are still developing,” said Dr. Jarvis.

In addition to changes in the brain, smoking marijuana irritates the lungs and can cause a chronic cough or bronchitis and can worsen asthma. In the long term, especially with marijuana use, there is a risk of psychotic disorders like schizophrenia.

Similarly, cocaine use can also cause long-term problems—even for casual users. Cocaine typically comes in two forms—powdered cocaine that is snorted through the nose or dissolved in water and injected into a vein, and crack cocaine that is smoked. Cocaine makes users feel like they are alert and have a lot of energy in addition to making them feel good. However, the drug can also cause feelings of anxiety, irritability and depression.

Cocaine increases the heart rate, narrows blood vessels, increases blood pressure and can cause erratic heart rhythms, which means that users are at risk of having a heart attack every time they use cocaine.

In addition to acute risks, a small study showed that occasional cocaine users showed long-term effects like higher systolic blood pressure, thicker arteries and thicker heart walls—all risks that increase the likelihood of a heart attack.

“You’re not only at risk for having a heart attack during your high, you are also increasing your risk long after the high has subsided,” said Dr. Jarvis.

In addition to its effects on the heart, cocaine also affects the parts of the brain that control rewards, which can create dependence and addiction over time.

Whether you use marijuana or cocaine once a week or once a month, using the drugs affects the whole body negatively.

“More research needs to be done to give us the full view of how drug use affects people long-term,” said Dr. Jarvis. “But what we know after initial studies is that they’re dangerous when they are used, even if on a casual basis.”
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