Substance use and addiction affect how the brain processes reward, stress, and control. These are medical conditions — not moral failures — and support can help people recover and regain stability.
People can struggle at different levels, from occasional misuse to addiction.
Substance use refers to the use of alcohol, medications, or drugs.
It becomes a concern when it:
Interferes with health or daily life
Causes problems at work, school, or in relationships
Is used to cope with stress, pain, or emotions
Not all substance use is addiction, but it can increase risk over time.
What addiction is and how it affects the brain and body.
Addiction is a complex condition that changes the brain’s reward system and creates a cycle of cravings, temporary relief, and loss of control. Over time, addiction can affect decision-making, health, relationships, and daily life.
What addiction is infographic describing how addiction affects the brain and body over time
Addiction (also called substance use disorder) involves ongoing use despite harm.
It may include:
Strong cravings or urges
Loss of control over use
Needing more to feel the same effect (tolerance)
Feeling unwell when stopping (withdrawal)
Addiction changes how the brain responds to reward and stress.
Behavioral signs may include:
Using more or longer than planned
Difficulty cutting back or stopping
Hiding or minimizing use
Neglecting responsibilities
Physical or emotional signs may include:
Changes in sleep or appetite
Mood swings or irritability
Anxiety or depression
Health problems related to use
Symptoms vary by substance and person.
Addiction affects brain systems that regulate reward, motivation, and self-control.
This may involve:
Overactivation of reward pathways
Reduced sensitivity to natural rewards
Weakened impulse-control networks
Increased stress and craving signals
These brain changes make stopping difficult without support.
Evaluation usually includes:
Discussion of substance use patterns
Impact on health and daily life
Screening tools or questionnaires
Medical assessment when needed
Diagnosis focuses on patterns and consequences, not judgment.
Substance use disorders are treatable.
Treatment may include:
Counseling or behavioral therapy
Medications to reduce cravings or withdrawal
Support groups or recovery programs
Medical care for related health issues
Many people use a combination of supports.
Helpful supports may include:
Structured routines
Avoiding triggers when possible
Building supportive relationships
Addressing stress, trauma, or mental health symptoms
Recovery often happens in steps, not all at once.
Seek immediate help if substance use involves:
Overdose risk or severe withdrawal
Confusion, seizures, or breathing problems
Thoughts of harming yourself
Feeling unsafe
In the U.S., call or text 988 for the Suicide & Crisis Lifeline.
For overdose emergencies, call 911.
Substance use and addiction can feel isolating, but recovery is possible with support.
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Understanding how addiction affects the brain can reduce shame and support healing.