How alcohol and drugs rewire the brain

The use of alcohol and drugs can dramatically alter brain structure and functioning, with far-reaching effects on behavior and cognition. Mielad Owraghi, LMFT lead clinical therapist, explains how these substances impact the brain, leading to profound changes in behavior and mental health.

"Substance use can mimic or inhibit the action of neurotransmitters by disrupting the brain's normal communication pathways,” Owraghi says. This disruption can cause a cascade of effects, altering mood, behavior, and cognitive function.

The Reward Pathway and Dopamine

One of the most significant impacts of addictive substances is on the brain's reward pathway, primarily through the release of dopamine. This neurotransmitter is associated with pleasure and reinforcement. Owraghi says many addictive substances activate the reward pathway, leading to intense feelings of pleasure and euphoria. The pleasurable sensation reinforces the desire to use the substance again, contributing to the development of dependency.

Neuroplasticity and Tolerance

Chronic use of alcohol and drugs can induce neuroplasticity, the brain's ability to reorganize itself by forming new neural connections. This can lead to changes in brain structure, making it more susceptible to addiction. 

“With repeated exposure, the brain may develop tolerance, requiring higher doses to achieve the same effects," Owraghi says. “This tolerance drives individuals to consume larger quantities, increasing the risk of addiction and other negative outcomes.”

Post-Acute Withdrawal Symptoms (PAWS)

Continued use of alcohol and drugs can lead to physical and psychological dependence, where the brain adapts to the presence of the substance and requires it to function normally. Withdrawal symptoms may occur when substance use is reduced or discontinued, further reinforcing the cycle of addiction. The withdrawals experienced in such circumstances are known as post-acute withdrawal symptoms (PAWS). PAWS refers to a set of prolonged withdrawal symptoms that can persist for weeks or months after the acute withdrawal phase of substance use has subsided. These symptoms typically occur in individuals who have undergone detoxification and initially experienced acute withdrawal symptoms, such as physical discomfort, cravings, and mood disturbances.

Post-acute withdrawal symptoms may include:

• Mood Swings: Fluctuations in mood, including irritability, anxiety, depression, and emotional instability.
• Cognitive Impairments: Difficulty with concentration, memory, and decision-making abilities.
• Sleep Disturbances: Insomnia, vivid dreams, or disturbances in sleep patterns.
• Physical Symptoms: Lingering physical discomfort, such as fatigue, headaches, muscle aches, and gastrointestinal issues.
• Cravings: Intense urges or cravings to use substances despite the desire to remain abstinent.
• Stress Sensitivity: Heightened sensitivity to stressors and difficulty coping with everyday challenges.
• Impaired Executive Functioning: Challenges in planning, organization, and problem-solving abilities.
• Social and Interpersonal Issues: Difficulty in social situations, strained relationships, and isolation.

“It's important to note that the duration and severity of post-acute withdrawal symptoms can vary widely depending on factors such as the type of substance used, the duration of use, individual differences in physiology and psychology, and the presence of co-occurring mental health conditions/disorders,” Owraghi says. 

Trauma and Addiction

The link between trauma and addiction is complex. Trauma can lead individuals to use substances as a coping mechanism, self-medicating to relieve distressing emotions and memories. Owraghi says trauma can lead to neurobiological changes, impacting areas of the brain involved in reward processing, impulse control, and emotional regulation. These changes can increase vulnerability to addiction, perpetuating a cycle of trauma and substance use.

“It's important to recognize that not all trauma survivors develop addiction, and not all individuals with addiction have experienced trauma,” Owraghi says. “However, trauma can significantly increase vulnerability to addiction and complicate the recovery process. Effective treatment for co-occurring trauma and addiction often involves trauma-informed approaches, addressing underlying trauma-related issues, and providing integrated care that addresses both mental health and substance use disorders.”

If you or someone you know is struggling with substance use or addiction, explore mental health care at Loma Linda University Behavioral Health.