---
title: "Selective Serotonin Reuptake Inhibitors (SSRIs) | Intro Psych"
description: "Selective serotonin reuptake inhibitors (SSRIs) are antidepressants that block serotonin reuptake, raising serotonin availability in Intro to Psychology cases."
canonical: "https://fiveable.me/intro-psychology/key-terms/selective-serotonin-reuptake-inhibitors"
type: "key-term"
subject: "Intro to Psychology"
unit: "Unit 15"
---

# Selective Serotonin Reuptake Inhibitors (SSRIs) | Intro Psych

## Definition

Selective serotonin reuptake inhibitors (SSRIs) are medications that block serotonin reuptake, which leaves more serotonin available in the brain. In Intro to Psychology, they show up as a common treatment for depression, anxiety, and OCD.

## What It Is

Selective serotonin reuptake inhibitors, or SSRIs, are a class of antidepressant medications used in Intro to Psychology to explain how changing brain chemistry can reduce symptoms of depression, anxiety, and obsessive-compulsive related disorders. Their main job is to block serotonin reuptake at the synapse.

That sounds technical, but the idea is simple: after a neuron releases serotonin, some of it normally gets taken back up by the sending neuron. SSRIs slow down that reabsorption, so more serotonin stays available between neurons for longer. Since serotonin is one of the neurotransmitters linked to mood and emotional regulation, this can ease symptoms over time.

SSRIs are called selective because they mainly target serotonin reuptake rather than affecting lots of different neurotransmitters at once. That makes them different from older antidepressants, which often had broader effects and more side effects. In psychology class, this is a good example of how a medication can influence behavior and emotion by changing communication in the nervous system.

These medications do not usually work instantly. A person may take them for several weeks before noticing meaningful improvement, which is a common point of confusion in class questions. The delay matters because the brain needs time to adjust to the changed serotonin activity, and symptoms like anxiety, obsessive thoughts, or low mood do not disappear the moment a pill is taken.

SSRIs are often discussed as first-line treatment for conditions like generalized anxiety disorder, panic disorder, social anxiety disorder, PTSD, and OCD. For OCD, they can help reduce the intensity of intrusive thoughts and compulsive behaviors. They are also used for some body-focused repetitive behaviors, such as trichotillomania and excoriation disorder, where repetitive urges are part of the clinical picture.

They can cause side effects, especially early on. Nausea, drowsiness, dry mouth, constipation, and sexual dysfunction are common examples. In Intro to Psychology, the big takeaway is not just that SSRIs exist, but that treatment often means balancing symptom relief, side effects, and how well the medication fits the person’s disorder.

## Why It Matters

SSRIs matter in Intro to Psychology because they connect the biology of the brain to the experience of mental illness. When you see a case description with persistent worry, panic attacks, intrusive thoughts, or compulsive rituals, SSRIs are one of the major treatment options you should recognize.

This term also helps you separate different kinds of anxiety and obsessive-compulsive related disorders from normal stress. A student might read about someone who cannot stop checking locks, or someone who has constant fear in social situations, and need to explain why a serotonin-based medication could reduce symptoms without being a cure-all.

SSRIs also give you a clean example of the biopsychological approach. Instead of treating behavior as just a choice or a personality trait, psychology looks at how neurotransmitters, brain circuits, and medication can shape mood and action. That is especially useful when you are comparing biological treatment with psychotherapy or behavior-based strategies.

They also show up in discussions of side effects and treatment planning. In class, you may be asked why a medication that helps mood might still not be ideal for every person. That answer usually involves time to take effect, tolerability, and the fact that mental health treatment often works best when it matches the specific disorder and the person’s needs.

## Connections

### Serotonin

SSRIs are built around serotonin, so you need to know what that neurotransmitter does in the brain. In Intro to Psychology, serotonin is usually linked with mood regulation, emotional stability, and some anxiety-related symptoms. SSRIs do not create serotonin from scratch, they keep more of it available after release.

### Reuptake

Reuptake is the process SSRIs block. After a neuron sends a signal, it normally takes back some of the neurotransmitter it released. When you understand reuptake, the medication’s effect makes sense, because SSRIs slow that cleanup step and change how long serotonin stays in the synapse.

### [Generalized Anxiety Disorder (GAD)](/intro-psychology/key-terms/gad)

GAD is one of the anxiety disorders commonly treated with SSRIs. The connection matters because GAD involves persistent, hard-to-control worry, and SSRIs are often used to lower the intensity of that ongoing anxiety. If you see a case with constant tension and excessive worry, this is one treatment you might expect.

### [Excoriation Disorder](/intro-psychology/key-terms/excoriation-disorder)

Excoriation disorder is a body-focused repetitive behavior where a person repeatedly picks at their skin. SSRIs sometimes come up here because the symptoms overlap with obsessive-compulsive related patterns. In class, this helps show that SSRIs are not only for depression, they can also be used when repetitive urges are part of the problem.

## On the AP Exam

A quiz item or short-answer question may give you a symptom pattern and ask which treatment fits best. If the scenario mentions depression, panic, intrusive thoughts, or compulsive behavior, SSRIs are a strong answer because they increase serotonin availability by blocking reuptake. You may also need to explain why the medication is not an instant fix, since symptom improvement usually takes time.

In a case study, look for the disorder first, then match the treatment to the symptoms. If the prompt includes side effects, you might identify nausea, drowsiness, or sexual dysfunction as common SSRI effects. On a discussion prompt, you could compare medication treatment with psychotherapy, especially for anxiety disorders and OCD.

## Selective Serotonin Reuptake Inhibitors (SSRIs) vs Serotonin

Serotonin is the neurotransmitter itself, while SSRIs are medications that change how serotonin is recycled after release. If you mix them up, the treatment mechanism gets backward. Think of serotonin as the chemical messenger and SSRIs as the drug that keeps more of that messenger available in the synapse.

## Key Takeaways

- SSRIs are antidepressant medications that block serotonin reuptake, leaving more serotonin available between neurons.
- In Intro to Psychology, SSRIs are most often discussed as treatments for depression, anxiety disorders, OCD, and some related repetitive-behavior disorders.
- They usually do not work right away, so delayed improvement is a normal part of how these medications are taught and used.
- Common side effects include nausea, drowsiness, dry mouth, constipation, and sexual dysfunction, especially early in treatment.
- SSRIs are a good example of the biopsychological approach because they connect neurotransmitters, brain function, and mental health symptoms.

## FAQs

### What is Selective Serotonin Reuptake Inhibitors (SSRIs) in Intro to Psychology?

SSRIs are a class of medications that treat mood and anxiety symptoms by blocking serotonin reuptake. In Intro to Psychology, they are usually discussed as a common biological treatment for depression, anxiety disorders, OCD, and related conditions.

### How do SSRIs work in the brain?

They prevent the neuron from taking back too much serotonin after it is released. That leaves more serotonin available in the synapse, which can improve mood and reduce anxiety or compulsive symptoms over time.

### Are SSRIs used for OCD or anxiety?

Yes. SSRIs are often used for anxiety disorders like generalized anxiety disorder, panic disorder, social anxiety disorder, and PTSD, and they are also common in OCD treatment. In OCD, they can help reduce intrusive thoughts and compulsive behaviors.

### What are common side effects of SSRIs?

Nausea, drowsiness, dry mouth, constipation, and sexual dysfunction are common side effects. These can be especially noticeable at first, and they may lessen as the body adjusts to the medication.

## Related Study Guides

- [15.5 Obsessive-Compulsive and Related Disorders](/intro-psychology/unit-15/5-obsessive-compulsive-related-disorders/study-guide/uZeFUOmxRDa3JwHd)
- [15.4 Anxiety Disorders](/intro-psychology/unit-15/4-anxiety-disorders/study-guide/wqEHufLyVLNie43O)

## 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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