Speakers - 2026

Title: Neurobiology of Addiction

Abstract

Addiction, a chronic relapsing brain disease where consequences are not merely the result of poor choices but the outcome of a persistent condition. It is a complex condition that does not stems from a single factor but rather from a dynamic interplay of biological, psychological, and social elements. Understanding this biopsychosocial model is essential to grasp the full scope of both its causes and its severe, long-lasting consequences. Addiction results from repeated long-term exposure to drugs, leading to changes in central nervous system, especially in the midbrain dopamine system, resulting in an addictive state with complex behaviors such as dependence, tolerance, sensitization, and craving. However, addiction leading to loss of volitional control (opiates, nicotine and illicit use of psychostimulants), if left untreated, can cause major medical, social, and economic problems.

Causes of Addiction: The Biopsychosocial Model

The development of addiction is determined by an individual’s vulnerability interacting with their environment. The primary factors can be categorized as follows.

A. Biological Factors (The “Bio” Component):

• Accounts for approximately 40–60% of a person’s risk for addiction
• Genetics and Heritability:  suggests a significant genetic component,

Specific genes can influence how a person’s brain responds to substances.

• Brain Chemistry and Function: All addictive substances and behaviors

target the brain’s reward circuit, centered in the limbic system (specifically

the nucleus accumbens) such as Dopamine Overload , Tolerance and Impaired Executive Function

B. Psychological Factors (The “Psycho” Component)

Psychological states and individual characteristics play a critical role in increasing the risk of substance use as a coping mechanism.

• Co-occurring Mental Health Disorders (Dual Diagnosis and  Self-Medication)

Drug addiction represents a dramatic dysregulation of motivational circuits caused by a combination of exaggerated incentive salience and habit formation, reward deficits and stress. Three phenomena characterize addiction: binge/intoxication, withdrawal/negative affect and craving (preoccupation/anticipation). Impulsivity and positive reinforcement often dominate the first stages, driving the motivation for drug seeking, and compulsivity and negative reinforcement dominate the terminal stages of the addiction cycle.

Thus, addiction is a multifaceted public health crisis rooted in an intricate relationship between an individual’s genetic makeup (biology), their coping mechanisms and mental health (psychology), and their environment (social context). The consequences are direct result of a chronic condition that systematically dismantles the physical, mental, and social well-being of the affected individual and those around them

Summary

• Addiction-relevant behaviors in animal studies model have led to an understanding of addiction neurobiology and identification of several genes mediating variation in drug preference and response

• The neurobiological pathways that modulate reward, stress resiliency and behavior inhibition are among those having underlying addiction liability.
• Variation in the neurobiology of addiction is genetically influenced by correlation of addiction liability with heritability.
• The individualization of treatment and prevention is likely to be advanced by the discovery of genetic predictors of the neurobiological pathways that underlie addiction