Heroin is one of the deadliest drugs in the United States. Learn about the mental health effects that heroin has on people who use the drug.

Heroin is one of the deadliest drugs in America. In 2017, the Centers for Disease Control and Prevention (CDC) reported that approximately 494,000 Americans ages 12 and older used heroin in the year before taking the survey. The CDC also reported that more than 15,000 people died from a heroin-related overdose during 2017.

These reports leave many people wondering, what are the psychological effects of heroin that make it so addictive and deadly?

The short- and long-term mental effects of heroin can completely change the way a person behaves and thinks. Once the euphoria from the high fades, people are left to face challenging withdrawal symptoms. Many people seek more heroin to avoid withdrawal symptoms.

It’s important to know the mental health effects that heroin causes to understand what people with heroin addiction face daily.

Article at a Glance:

Heroin’s powerful short- and long-term mental effects make it addictive, harmful and deadly. Keep the following key points in mind regarding the mental effects of heroin:

  • Some of heroin’s short-term mental side effects include euphoria, warmth, calmness, delirium, and drowsiness
  • Heroin dependence, tolerance, addiction and withdrawal symptoms can develop from long-term heroin use
  • Heroin is so potent that addiction can develop after a single-use
  • Thousands of people die from heroin-related overdoses each year

Short-Term Mental Effects of Heroin

The short-term mental effects of heroin are what someone feels when they get high. The nature and strength of these effects depend upon the individual’s tolerance to heroin and specific drug-related factors: dose, purity, route of administration and co-ingestion with other substances.

What are the short-term effects of heroin?

  • Euphoria: Heroin’s euphoria begins within seconds and lasts for a few minutes. This rush of pleasure is due to heroin’s high absorption rate in the bloodstream, making it even more addictive than morphine. Heroin is so intense that some people become addicted to the drug after just one use.
  • Warmth: Sensations of warmth and burning may blend into the initial euphoric state. Interestingly, body temperature does not rise with heroin use. This feeling of warmth is simply a short-term mental effect of the drug.
  • Analgesia: The arms and legs may start to feel heavy, and the body may feel little to no pain. Just like prescription opioid medications, heroin is a pain reliever. It is effective in relieving physical and emotional pain. This analgesic effect lessens as tolerance develops.
  • Calmness: Together, these pleasurable feelings contribute to a sense of calmness, wellness and security. This initial calming effect is short-lived. Unfortunately for the individual using heroin, the drug does not make their mental or physical health any better, nor does it make their situation any safer.
  • Drowsiness: The individual may also feel drowsy, falling in and out of sleep. In this way, heroin can serve as a sleep aid. Unfortunately, the quality of sleep it produces is poor. Over time, heroin ends up disrupting sleep instead of improving it.
  • Changes in mood, memory and attention: Heroin worsens memory and attention. It also creates negative changes in mood. These disturbances in cognition and mood can prompt an individual to start looking for their next dose of heroin.
  • Opioid-induced mental health conditions: The following conditions can be provoked by heroin intoxication.
    • Opioid intoxication delirium: waxing and waning of orientation and attention
    • Opioid-induced psychotic disorder: altered bodily senses, impaired sense of reality and unusual speech or behavior
    • Opioid-induced mood disorder: most commonly with mixed manic and depressive symptoms
    • Opioid-induced sleep disorder: most commonly hypersomnia (sleeping too much)
    • Opioid-induced sexual dysfunction: most commonly impotence (inability to have an erection or orgasm)

Heroin can be snorted, smoked or injected. Heroin injected into the vein rather than into muscle or fat delivers the most immediate and longest-lasting high. The maximum intensity of the high can last for hours, as opposed to minutes when people smoke or snort heroin. Injected heroin is more potent because it travels faster and more extensively through the bloodstream to the brain.

Long-Term Mental Effects of Heroin

The long-term mental effects of heroin begin with the development of drug tolerance and drug dependence, followed by drug withdrawal and culminating in drug addiction. After long-term heroin use, a person’s heroin tolerance and dependence increase. At that point, the drug is no longer used to get high, but simply to avoid withdrawal symptoms.

What are the long-term effects of heroin?

  • Tolerance: Tolerance is when a drug gives a diminished high after repeated use. People who develop a tolerance to heroin may show little signs of being high after using the drug. These individuals may go on to ingest heroin of a higher purity or dose, or via a faster route of administration, to recapture the euphoria of their first high.
  • Dependence: Psychological and physical dependence on heroin develops when an individual cannot function normally without the drug. Dependence can begin within days of first use. Signs of heroin dependence include continued anticipation and prioritization of heroin use despite personal and professional consequences.
  • Withdrawal: Heroin withdrawal occurs due to an abrupt cessation of use in people with opioid dependence. It can also occur with premature administration of an opioid antagonist medication to reduce craving (i.e., naltrexone) or to treat overdose (i.e. naloxone). Withdrawal is especially concerning in pregnant women, as it can be life-threatening for fetuses and newborns. Notable mental effects of heroin withdrawal include:
    • Mood swings
    • Agitation or irritability
    • Fatigue
    • Anhedonia (lack of motivation or pleasure)
    • Insomnia
    • Difficulty concentrating
    • Anxiety
    • Depression
  • Addiction: Also known as a substance use disorder, addiction is an acquired disease of the brain that affects the brain’s reward system. Often, the personal and professional consequences of the individual’s drug use are life-altering or life-threatening. Addiction occurs under necessary and sufficient conditions.
    • Necessary conditions: genetic predisposition to addiction, or first use of the substance at an early age
    • Sufficient conditions: poor coping with trauma and adversity, and continuous use of the substance

How Addiction Changes Your Brain

Drugs like heroin hijack the brain’s reward system, strengthening the desire to use more heroin. The reward system’s biological purpose is to reinforce natural rewards. Such rewards include life-sustaining behaviors like eating, sleeping, working, socializing, procreating and parenting.

Your brain’s cells, known as neurons, first anticipate the drug in the thalamus, the brain’s relay center. This anticipation generates an electrical signal in one neuron that causes a neighboring neuron to release chemical messengers. These chemical messengers, known as neurotransmitters, bind to their receptors on the next neuron, regenerating the electrical signal. This process continues until the signal reaches the brainstem.

Anticipated or actual heroin use signals the midbrain structure of the brainstem to release the pleasure neurotransmitter, dopamine, from its sites of production, known as the ventral tegmental area and the substantia nigra.

Drugs like heroin produce much more dopamine than natural rewards do. This surge of dopamine then projects on to receptors in other areas of the brain:

  • Amygdala: where emotions evoked by the drug are processed
  • Insula and hippocampus: where emotions and memories regarding craving and drug-seeking behavior are processed
  • Prefrontal cortex: where the choice to use is weighed and executed
  • Nucleus accumbens: where motor activity associated with reward obtainment and reinforcement is initiated

Chronic heroin use repeatedly floods the reward system with dopamine. The brain adapts by decreasing its dopamine production in response to natural rewards and drugs. It also decreases the number of dopamine receptors and increases the number of opioid receptors. Together, these brain changes result in psychological and physical dependence, and the need for greater heroin consumption to overcome tolerance and avoid withdrawal.

The levels of other neurotransmitters and hormones are also altered:

  • Serotonin: the contentment neurotransmitter, increases with short-term heroin use, and decreases with long-term use. Anxiety, depression and other negative emotional states increase as a result.
  • Glutamate: a stimulating neurotransmitter associated with learning and memory increases with heroin use, cementing the desire to use
  • GABA: a neurotransmitter that inhibits dopamine release, decreases with heroin use, increasing the potential for addiction
  • Endorphins: the body’s natural opioids, increase with short-term heroin use, and decrease with long-term use
  • Corticotropin-releasing hormone (CRH): this hormone increases with heroin use, increasing the production of the stress hormone, cortisol
  • Cortisol: a hormone that helps mediate stress. In the short-term, increased cortisol is protective, but in the long-term, it is damaging to our minds and bodies. Both gray and white matter of the brain are damaged, resulting in impaired brain functioning and connectivity.

Fortunately, there is a silver-lining: Treatment with abstinence, medication, and therapy, as seen in fMRI and PET imaging studies, can reverse some of the brain damage caused by heroin in as little as six months. Recovery from heroin addiction is possible and can be life-saving.

If you or a loved one struggle with heroin addiction, The Recovery Village can help. You can receive comprehensive treatment for heroin addiction from one of several facilities located throughout the country. To learn more about heroin treatment programs, call The Recovery Village to speak with a representative today. 

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Editor – Thomas Christiansen
With over a decade of content experience, Tom produces and edits research articles, news and blog posts produced for Advanced Recovery Systems. Read more
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Medically Reviewed By – Dr. Lauren Weinand, MD
Dr. Lauren Weinand is an M.D. medical writer/editor. Read more

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Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.