---
title: "First-Generation Antipsychotics | Abnormal Psych"
description: "First-generation antipsychotics are older schizophrenia medications that block D2 dopamine receptors, reducing hallucinations and delusions in Abnormal Psychology."
canonical: "https://fiveable.me/abnormal-psychology/key-terms/first-generation-antipsychotics"
type: "key-term"
subject: "Abnormal Psychology"
unit: "Unit 16"
---

# First-Generation Antipsychotics | Abnormal Psych

## Definition

First-generation antipsychotics are older psychotic-disorder medications that block D2 dopamine receptors, which can reduce hallucinations and delusions. In Abnormal Psychology, they’re a core example of biological treatment for schizophrenia.

## What It Is

First-generation antipsychotics are the original class of antipsychotic medications used in Abnormal Psychology to treat psychosis, especially the positive symptoms of schizophrenia such as hallucinations, delusions, and disorganized thinking. Drugs like chlorpromazine and haloperidol are classic examples.

These medications work mainly by blocking dopamine D2 receptors. That matters because too much dopamine activity in certain brain pathways is linked to psychotic symptoms. When D2 receptors are antagonized, the brain gets less of that overactive dopamine signaling, and symptoms can become less intense.

The flip side is that dopamine is not only involved in psychosis. It also helps regulate movement and reward, so blocking it can cause side effects. That is why first-generation antipsychotics are associated with extrapyramidal symptoms, such as muscle stiffness, tremors, restlessness, and in some cases tardive dyskinesia, which can involve involuntary movements after long-term use.

These medications were a major breakthrough in the 1950s because they gave clinicians a way to reduce severe psychotic symptoms without relying only on hospitalization or sedation. They are still used today, especially when cost matters or when a person responds well to them. But they are often balanced against their side effect burden, which is a big reason second-generation antipsychotics later became more common.

In a class discussion or case example, you might see first-generation antipsychotics described as better for positive symptoms than negative symptoms. That distinction helps you connect the medication to the symptom pattern you are analyzing, instead of treating all psychotic symptoms as the same.

## Why It Matters

This term shows up whenever Abnormal Psychology covers biological treatments for schizophrenia and other psychotic disorders. It gives you a concrete example of how altering neurotransmitter activity can change behavior, perception, and thinking.

It also helps you interpret treatment tradeoffs. A case might describe a patient whose hallucinations improve on haloperidol but who develops tremors or facial movements later. Knowing first-generation antipsychotics lets you connect the symptom relief with the risk of extrapyramidal side effects and tardive dyskinesia.

The term also sets up comparisons with second-generation antipsychotics, which are often discussed as a newer alternative with a different side effect profile. If you can explain why the older drugs were effective but limited, you are showing that you understand both the mechanism and the clinical decision-making behind psychopharmacology.

## Connections

### [Dopamine D2 Receptors](/abnormal-psychology/key-terms/dopamine-d2-receptors)

First-generation antipsychotics work by blocking D2 receptors, so this is the receptor-level idea behind the medication class. If you understand D2 antagonism, you can explain why these drugs reduce psychosis and why they also affect movement. The receptor target is the bridge between brain chemistry and symptom change.

### Extrapyramidal Symptoms (EPS)

EPS are one of the main side effect groups tied to first-generation antipsychotics. They can include stiffness, tremor, akathisia, and other movement problems because dopamine blockade affects motor circuits. If a case mentions a patient developing involuntary movements after antipsychotic use, EPS is one of the first connections to make.

### [Second-generation antipsychotics](/abnormal-psychology/key-terms/second-generation-antipsychotics)

Second-generation antipsychotics are the newer comparison point for this drug class. They are often introduced as having a different side effect profile and broader effects on symptoms. When you compare the two, you are usually looking at how newer medications try to keep antipsychotic benefits while reducing movement-related side effects.

### Dopamine

Dopamine is the neurotransmitter most closely tied to the action of first-generation antipsychotics. In Abnormal Psychology, excess dopamine activity is often used to explain psychotic symptoms, so blocking dopamine can lower those symptoms. This connection helps you move from a brain-based theory to the actual medication mechanism.

## On the AP Exam

A quiz question or case vignette usually asks you to identify a first-generation antipsychotic from its effects, especially if the person has reduced hallucinations but later shows stiffness, tremors, or tardive dyskinesia. You may also be asked to explain why these drugs help psychosis by naming dopamine D2 receptor blockade. In short-answer prompts, the best move is to connect the symptom pattern to the medication class and then mention the side effect tradeoff. If the question compares treatment options, point out that these older drugs are effective and often cheaper, but they are more likely to cause movement-related adverse effects than newer alternatives.

## first-generation antipsychotics vs Second-generation antipsychotics

These two classes are easy to mix up because both treat psychosis. First-generation antipsychotics mainly block D2 receptors and are more associated with extrapyramidal symptoms, while second-generation antipsychotics are usually discussed as having a different receptor profile and fewer movement side effects. If a question focuses on EPS or tardive dyskinesia, it is usually pointing to the first-generation class.

## Key Takeaways

- First-generation antipsychotics are older medications used to reduce psychotic symptoms, especially hallucinations and delusions.
- They work mainly by blocking dopamine D2 receptors, which lowers dopamine activity linked to psychosis.
- Their main drawback is side effects, especially extrapyramidal symptoms and tardive dyskinesia.
- These drugs are still used in some cases because they can be effective and are often less expensive.
- In Abnormal Psychology, they are a classic example of how biological treatment can help one symptom set while creating another clinical tradeoff.

## FAQs

### What is first-generation antipsychotics in Abnormal Psychology?

First-generation antipsychotics are older antipsychotic medications used to treat psychotic disorders like schizophrenia. They reduce positive symptoms such as hallucinations and delusions by blocking dopamine D2 receptors. The big tradeoff is that they can cause movement-related side effects.

### How do first-generation antipsychotics work?

They work mainly by antagonizing D2 dopamine receptors in the brain. That lowers dopamine signaling in pathways linked to psychosis, which can reduce symptoms. The same dopamine blockade can also interfere with normal motor function, which is why side effects are such a common part of the discussion.

### What are common side effects of first-generation antipsychotics?

Common side effects include sedation and extrapyramidal symptoms such as muscle stiffness, tremors, and akathisia. Long-term use can also raise the risk of tardive dyskinesia, which involves involuntary movements. These side effects are a big reason newer antipsychotics are often compared with the older drugs.

### How are first-generation and second-generation antipsychotics different?

Both are used for psychosis, but first-generation antipsychotics are more strongly tied to D2 blockade and movement side effects. Second-generation antipsychotics are usually presented as having a different receptor profile and a lower risk of EPS. If a question mentions tremors or tardive dyskinesia, that usually points toward the first-generation class.

## Related Study Guides

- [16.2 Biological Treatments](/abnormal-psychology/unit-16/biological-treatments/study-guide/c03H5n5ME6E1MCdW)

## About This Document

Canonical Fiveable pages are available as Markdown at the same path plus `.md`.

- [llms.txt](https://fiveable.me/llms.txt): index of Fiveable's sections and URL patterns
- [llms-full.txt](https://fiveable.me/llms-full.txt): complete subject and unit listing
- [MCP server](https://fiveable.me/mcp): call Fiveable as tools instead of fetching pages (`https://fiveable.me/api/mcp`)
- [MCP server for AP teachers](https://fiveable.me/mcp/teachers): a teacher's classes, assignments and AP-rubric grading (`https://fiveable.me/api/mcp/teacher`)

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