Health Effects of Casual Drug Use

Even recreational drug use can cause lasting harm to your brain, heart and lungs

The lasting effects of heavy drug use are well known — addiction, serious health issues, infectious diseases and changes in the way a person thinks. But what if you only use occasionally, like while out with friends, in certain social settings or during a stressful life event?

“Using drugs — no matter how infrequent — can also have negative effects on behavior and overall health, especially for younger people,” says Kim Kabernagel, DO, medical director of Geisinger Marworth Treatment Center in Waverly. “While smoking marijuana or using other drugs every now and then might not seem like a big deal, recreational use can still leave a lasting effect on your brain, heart and lungs.”

The fact is, there’s no safe level of drug use; any amount is gambling with your health. Quitting completely will greatly benefit your health and safety — and could add years to your life.

What does casual drug use mean?

Casual or recreational drug use refers to occasional use of a substance without feeling dependent.

People might set limits, like only using on weekends, on special occasions or while out with certain friends. Or they may use drugs to get through a stressful event and then stop — until another stressor comes along.

Recreational drug use may seem harmless, especially if it doesn’t interfere with daily responsibilities at home and work.

“Even so, risks exist because drug potency varies and effects can be unpredictable, especially when combined with alcohol or other meds,” says Dr. Kabernagel. “And patterns of casual use can change quickly when tolerance builds or life stressors become overwhelming.”

Long-term health effects of recreational drug use

The health effects of recreational drug use are similar to those of heavy, frequent use, including brain changes, respiratory issues, cardiovascular disease and depression.

“A huge risk of recreational drug use is the possibility that it could lead to gradually using more,” says Dr. Kabernagel. “What begins as harmless experimentation at a party can easily lead to more consistent, habitual use, making it much more difficult to quit — and negatively impacting your health even more.”

Brain changes

Even using drugs as little as once a week can change the brain’s structure and chemistry. When you take stimulants like cocaine or certain prescription drugs, it floods the brain with dopamine, the feel-good neurotransmitter linked to pleasure and reward. That’s what creates the intense feelings of euphoria and pleasure.

Over time, the brain adapts by reducing its response to dopamine, which can lessen the high. This effect is known as tolerance.

“The brain’s ‘reward circuit’ motivates us to repeat behaviors needed to thrive, like eating and spending time with loved ones,” says Dr. Kabernagel. “Surges in the ‘reward circuit’ of unhealthy behaviors that bring pleasure work the same way and can lead people to take drugs again and again, increasing tolerance and the risk of addiction.”

In addition, intermittent use can affect cognitive function, such as:

Decision making
Impulse control
Memory
Concentration
Processing speed

“In real-life scenarios, this cognitive impairment can lead to risky decisions like unsafe sex or driving under the influence — and result in serious consequences,” says Dr. Kabernagel.

Mental health problems

Even infrequent drug use can trigger or exacerbate existing mental health issues. Stimulants can cause panic, lethargy and restlessness, while depressants and marijuana can lead to low mood, apathy or emotional numbness.

“After taking a stimulant, users will experience the ‘comedown’ effect as brain chemicals return to normal levels,” says Dr. Kabernagel. “This can bring on irritability, low mood, sadness or loss of pleasure, which can make emotional regulation and day-to-day tasks feel more difficult.”

Over time, these cycles can contribute to mood disorders that persist even without recent drug use. And it can lead to a cycle of dependence where a person uses drugs to alleviate negative feelings, while making anxiety and depression worse.

Decline in physical health

Intermittent drug use can cause a range of serious physical health problems, including:

Cardiovascular disease. Stimulants like cocaine and certain prescription meds raise heart rate and blood pressure. Over time, this can damage blood vessels and increase the risk of arrhythmias, chest pain and, in severe cases, heart attack or stroke.

“Research revealed occasional cocaine users showed long-term effects including higher systolic blood pressure, thicker arteries and thicker heart walls,” says Dr. Kabernagel. “So, you’re not only at risk for having a heart attack during your high, but you’re also increasing your risk long after the high has subsided.”

Respiratory problems. Smoking any type of drug exposes the lungs to irritants that damage lung tissue and decrease function. Even recreational drug use can worsen asthma, lead to frequent infections like bronchitis and pneumonia, and increase risks of chronic cough, lung diseases and cancer. And inhaling vapors or powders isn’t safer. These routes also damage nasal passages and airways.

“Opioids can depress breathing and combining them with alcohol or other sedatives dangerously increases the risk of respiratory failure,” says Dr. Kabernagel. “Even brief episodes of low oxygen can cause lasting harm to the brain and heart.”

Decline in liver and kidney function. The liver metabolizes most drugs and the kidneys filter out the waste, or toxins from drugs. Over time, this can lead to inflammation (hepatitis or nephritis), fatty liver disease and kidney damage or even failure.

“Whether you use marijuana or cocaine once a week or once a month, using drugs affects the whole body negatively,” says Dr. Kabernagel. “Casual drug use may seem low risk, yet even intermittent use can affect the brain, heart, lungs, liver and kidneys.”

When to seek help for casual drug use

Increased stress, social pressures or tolerance can easily shift habits from occasional to more frequent drug use.

Early recognition and support can help prevent escalation — and the long-term health effects of drug use. Checking in with a therapist, addiction counselor or your primary care physician early can help you set goals, understand risks and develop a plan to stop using.

“Continued research is necessary to give us the full view of how drug use affects people long term,” says Dr. Kabernagel. “But what we know after initial studies is that they have the potential to be dangerous, even when used on a casual basis.”