Modern medicine doesn’t just treat infections or pain—it also treats the mind itself. Conditions such as depression, schizophrenia, Parkinson’s disease, and addiction are deeply rooted in chemical imbalances within the brain. The drugs used to manage these disorders form the backbone of CNS pharmacology.
UNIT 5 highlights psychopharmacological agents, neurodegenerative disease therapies, stimulants, opioids, and addiction science, explaining how brain chemistry is carefully modified to restore mental and neurological health.
Psychopharmacological Agents
Psychopharmacology deals with drugs that affect mood, behavior, and cognition.
Antipsychotics
Used in schizophrenia and severe psychosis by blocking dopamine receptors.
Examples
- Chlorpromazine
- Haloperidol
- Risperidone
Benefits
- Reduce hallucinations
- Control agitation
- Improve behavior
Atypical agents produce fewer motor side effects.
Antidepressants
These drugs enhance serotonin or norepinephrine levels.
Examples
- Fluoxetine
- Amitriptyline
Used to treat depression, anxiety, and mood disorders.
Anti-Anxiety Agents
Example
- Diazepam
They enhance GABA activity, producing calming effects.
Anti-Manic Drugs
Example
- Lithium carbonate
Used in bipolar disorder to stabilize mood swings.
Hallucinogens
These alter perception and cognition.
Examples include LSD-like substances used mainly in research.
Though not therapeutic in routine practice, they help understand brain chemistry.
Drugs for Parkinson’s and Alzheimer’s Disease
Neurodegenerative diseases require long-term pharmacological support.
Parkinson’s Disease
Caused by dopamine deficiency.
Drugs
- Levodopa
- Carbidopa
These improve motor control and reduce tremors.
Alzheimer’s Disease
Linked with reduced acetylcholine levels.
Drugs
- Donepezil
Improve memory and cognitive function temporarily.
CNS Stimulants and Nootropics
These enhance alertness and mental performance.
CNS Stimulants
Example
- Caffeine
Increase wakefulness and concentration.
Used in ADHD and narcolepsy treatment.
Nootropics
Cognitive enhancers that improve memory and learning.
Help in neurodegenerative conditions and brain fatigue.
Opioid Analgesics and Antagonists
Opioids are powerful pain relievers but carry addiction risk.
Opioid Analgesics
Examples
- Morphine sulfate
- Fentanyl
Used in severe pain management.
Opioid Antagonists
Example
- Naloxone
Reverse respiratory depression during overdose.
Drug Addiction, Abuse, Tolerance, and Dependence
Drug Addiction
Compulsive drug use despite harm.
Drug Abuse
Non-medical or improper use of drugs.
Tolerance
Higher doses required for same effect.
Dependence
Withdrawal symptoms occur on stopping.
Prevention Strategies
- Rational prescribing
- Patient education
- Monitoring therapy
- Regulatory control
Understanding these concepts is essential for safe pharmacotherapy.
Why CNS Pharmacology Matters
CNS drugs help manage:
- Mental illnesses
- Neurodegenerative disorders
- Severe pain
- Cognitive impairment
They directly influence quality of life and mental health.