Heroin Effects on the Brain
Table of Contents
The effect heroin has on the brain was not well understood until 1972, when a group of researchers from Johns Hopkins University revealed that the human brain possesses specific protein receptor sites for opiates, including codeine, opium, morphine and even heroin.2 Not long after these opiate-specific receptors were identified, researchers also discovered that the body produces its own
endogenous opioids, including dynorphin, enkephalin and endorphins. When opioids bind to these opiate-specific receptors within the brain, they are able to decrease the body’s perception of pain and elevate mood by increasing levels of dopamine.2,3 When the body is introduced to heroin, the body gets flooded with these opioids, leading to enormously high levels of dopamine.
Upon entering the brain, enzymes convert heroin back into morphine. Once in morphine form, it quickly binds to opioid receptors in the brain.3 This binding action triggers sensations of pain relief and even euphoria – which are more intense than the sensations produced by the body’s own endorphins binding to these receptors.
This is likely due to the fact that the levels of dopamine flooding the body when using heroin is much greater than the amount of dopamine naturally produced by the body for pain relief or pleasure.4 In fact, some estimates have suggested that using heroin can increase the body’s dopamine levels up to 10 times their normal level.5
Heroin reaches the brain the fastest when it is injected intravenously directly into the bloodstream or vaporized and smoked.6
After a period of exposure to a steady flux of opioids and the resultant, persistently elevated amount of dopamine, individuals begin to adjust and build tolerance to heroin. Pain thresholds are effectively lowered, and sensitivity to pain signaling is amplified. There has been some
suggestion that changes of these sorts can occur within the brain after a single administration of the drug.4 Surprisingly soon after heroin use begins, pain signaling pathways can become overactive – resulting in the user feeling the need for more and more heroin just to feel "normal."
Long-term use of heroin begins to take a toll on the prefrontal cortex and medial temporal lobe of the brain – areas that are associated with long-term memory, decision-making, complex thought and controlling one’s own social behavior.7-9
The following behavioral changes may be seen when these areas of the brain are altered from long-term heroin use10-15:
- Poor ability to regulate one’s own behaviors.
- Impaired emotional processing.
- Impaired memory.
- Poor executive functioning.
- Diminished ability in being flexible with tasks.
- Impaired reasoning skills.
- Poor ability to problem-solve.
- Poor planning skills.
- Decreased capacity for making decisions.
- Decreased ability to imagine future events and interactions.
A Brief Look into Heroin’s History
Before the 1923 U.S. ban on heroin use and distribution, physicians used to commonly prescribe heroin for pain treatment. The well-known pharmaceutical company Bayer used to even promote heroin as a non-addictive cough medicine for children.
Today, heroin is still used medically in the U.K. under its generic name "diamorphine" as a cough suppressant and analgesic for managing symptoms of severe or refractory pain.16
In the U.S., however, it is illegal to use, sell or manufacture heroin. Heroin is classified as a Schedule I controlled substance by the Drug Enforcement Administration (DEA) and is considered to be among the most dangerous drugs, due to its extremely high potential for abuse and dependence.1
Escape the Dangers of Heroin Addiction
Heron addiction is one of the most challenging drug addictions to break. Even after just one use, heroin can lead to changes within the brain that make it more likely for an individual to use the drug again.1 There are a number of treatment options available, however, that can help turn your dream of getting off of heroin into a reality.
Heroin rehabilitation programs treat both the psychological and physical effects of heroin addiction by incorporating a wide range of strategies and tools, including:
- Heroin detox.
- Counseling – either individually or in a group or both.
- Behavioral therapy.
- Addiction education.
- Dual diagnosis treatment and care for any additional medical conditions you may have.
- Relapse prevention skill training.
- Support group participation.
These programs also frequently use pharmaceutical treatment to help heroin users more gently wean their bodies off of heroin. If you or someone you love is exhibiting the signs and symptoms of heroin addiction, call one of our caring recovery advisors to learn more information on getting the help you need to break free from addiction.
- National Institute on Drug Abuse: Heroin.
- Waldhoer M, Bartlett SE, Whistler JL. Opioid receptors. Annu Rev Biochem 2004;73:953-990.
- Kreek MJ, Levran O, Reed B, Schlussman SD, Zhoi Y, Butelman ER. Opiate addiction and cocaine addiction: Underlying molecular neurobiology and genetics. J Clin Invest 2012;122(10):3387-3393.
- Johnson SW, North RA. Opioids excite dopamine neurons by hyperpolarization of local interneurons. J Neurosci 1992;12(2):483-488.
- Rook EJ, van Ree JM, van den Brink W, Hillebrand MJ, Huitema AD, Hendriks VM, Beijnen JH. Pharmacokinetics and pharmacodynamics of high doses of pharmaceutically prepared heroin, by intravenous or by inhalation route in opioid-dependent patients. Basic Clin Pharmacol Toxicol 2006;98(1):86-96.
- Drugs-Forum.com. The dangers of heroin.
- Cheng GLF, et al. (2013). Heroin abuse accelerates biological aging: a novel insight from telomerase and brain imaging interaction. Translational Psychiatry, 3. 1–9
- Ersche KD, Clark L, London M, Robbins TW, & Sahakian BJ. (2006). Profile of executive and memory function associated with amphetamine and opiate dependence. Neuropsychopharmacology, 31. 1036–1047
- Liu H, Hao Y, Kaneko Y, Ouyan X, Zhang Y, Xu L, Xue Z, & Liu Z. (2009). Frontal and cingulate gray matter volume reduction in heroin dependence: optimized voxel-based morphometry. Psychiatry Clinical Neuroscience, 63. 563–568
- Curran HV, Kleckham J, Bearn J, Strang J, & Wanigaratne S. (2001). Effects of methadone on cognition, mood and craving in detoxifying opiate addicts: a dose response study. Psychopharmacology, 154. 153–160.
- Friswell J, Phillips C, Holding J, Morgan CJA, Brandner B, & Curran HV (2008). Acute effects of opioids on memory functions on healthy men and women. Psychopharmacology, 198. 243–250.
- Fernández-Serrano MJ, Pérez-García M, & Verdejo-García A. (2011). What are the specific vs. generalized effects of drugs of abuse on neuro-psychological performance? Neuroscience of Biobehavior Review, 35. 377–406
- Fishbein DH, et al. (2007). Neurocognitive characterizations of Russian heroin addicts without a significant history of other drug use. Drug and Alcohol Dependence, 90. 25–38.
- Aguilar de Arcos F, et al. (2008). Dysregulation of emotional response in current and abstinent heroin users: negative heightening and positive blunting. Psychopharmacology, 198. 159–166.
- Mercuri K, et. al. (2015). Episodic foresight deficits in long-term opiate users. Psychopharmacology, 232. 1337-1345.
- Goldstein A. Heroin addiction: Neurobiology, pharmacology, and policy. J Psychoactive Drugs 1991;23(2):123-133.