Neuroimaging has shown functional and structural alterations in the brain. A 2017 study showed that chronic intake of opioids, such as heroin, may cause long-term effects in the orbitofrontal area (OFC), which is essential for regulating reward-related behaviors, emotional responses, and anxiety. Moreover, neuroimaging and neuropsychological studies demonstrated dysregulation of circuits associated with emotion, stress and high impulsivity. Dependence
Drug dependence is an adaptive state associated with a withdrawal syndrome upon cessation of repeated exposure to a stimulus (e.g., drug intake). Dependence is a component of a substance use disorder. Opioid dependence can manifest as physical dependence, psychological dependence, or both.Increased brain-derived neurotrophic factor (BDNF) signaling in the ventral tegmental area (VTA) has been shown to mediate opioid-induced withdrawal symptoms via downregulation of insulin receptor substrate 2 (IRS2), protein kinase B (AKT), and mechanistic target of rapamycin complex 2 (mTORC2). As a result of downregulated signaling through these proteins, opiates cause VTA neuronal hyperexcitability and shrinkage (specifically, the size of the neuronal soma is reduced). It has been shown that when an opiate-naive person begins using opiates in concentrations that induce euphoria, BDNF signaling increases in the VTA.Upregulation of the cyclic adenosine monophosphate (cAMP) signal transduction pathway by cAMP response element binding protein (CREB), a gene transcription factor, in the nucleus accumbens is a common mechanism of psychological dependence among several classes of drugs of abuse. Upregulation of the same pathway in the locus coeruleus is also a mechanism responsible for certain aspects of opioid-induced physical dependence.
Charts of deaths involving specific opioids and classes of opioids

History
Opiate misuse has been recorded at least since 300 BC. Greek mythology describes Nepenthe (Greek “free from sorrow”) and how it was used by the hero of the Odyssey. Opioids have been used in the Near East for centuries. The purification of and isolation of opiates occurred in the early 19th century.Levacetylmethadol was previously used to treat opioid dependence. In 2003 the drugs manufacturer discontinued production. There are no available generic versions. LAAM produced long-lasting effects, which allowed the person receiving treatment to visit a clinic only three times per week, as opposed to daily as with methadone. In 2001, levacetylmethadol was removed from the European market due to reports of life-threatening ventricular rhythm disorders. In 2003, Roxane Laboratories, Inc. discontinued Orlaam in the US. See also
Benzodiazepine withdrawal syndrome
Doctor shopping
Hyperkatifeia, hypersensitivity to emotional distress in the context of opioid abuse
Physical dependence
Post-acute-withdrawal syndrome
Prescription drug abuse

References
External links
Heroin information from the National Institute on Drug Abuse
Opioid information at Opioids.Net
Opioid Dependence Treatment and Guidelines
Opioid Risk Tool (ORT) for Narcotic Abuse