Psychopharmacology – Antipsychotics and Antidepressants

Why Your Brain Needs to Know These Medications

Imagine you're working with a client who's hearing voices that terrify them, or someone so depressed they can't get out of bed. As a psychologist, you won't prescribe medications, but you'll absolutely need to understand what your clients are taking. You'll be the one noticing when someone's hands start shaking from their meds, or when they're struggling with side effects they're too embarrassed to mention to their psychiatrist. This knowledge isn't just for the EPPP—it's for keeping your future clients safe.

Today we're tackling two major drug categories: antipsychotics (for conditions like schizophrenia) and antidepressants (for depression and anxiety disorders). Think of this lesson as learning to read the instructions on equipment you'll never operate yourself, but that your colleagues use every day. You need to know how it works, what can go wrong, and when to speak up.

The Big Picture: How These Drugs Work

Before we dive into specific medications, here's the fundamental concept: Most psychiatric medications work like volume controls for different chemicals in your brain. When someone has schizophrenia, certain brain chemicals (particularly dopamine) are turned up too loud in some areas. When someone has depression, other chemicals (like serotonin) aren't loud enough. These medications adjust those volume levels.

The catch? Your brain is more like a sound system with dozens of interconnected speakers than a simple stereo. When you adjust one volume, you often affect others—which explains why these drugs have side effects.

Antipsychotics: The Three Generations

First-Generation Antipsychotics (The Original Formula)

The first-generation antipsychotics (FGAs)—also called "typical" antipsychotics—are like the first smartphones. They did the basic job but came with some serious drawbacks. The main players are chlorpromazine (Thorazine), haloperidol (Haldol), thioridazine (Mellaril), and fluphenazine (Prolixin).

How they work: These drugs are dopamine blockers. They primarily block D2 dopamine receptors, which is like putting a cork in a bottle—dopamine can't get through. This helps with "positive symptoms" of schizophrenia (hallucinations, delusions, disorganized thinking), but it's not as effective for "negative symptoms" (flat emotions, lack of motivation, social withdrawal).

The side effects—three categories to remember:

Anticholinergic effects (think: "anti-choice" for your body's basic functions):

• Most common with low-potency FGAs like chlorpromazine and thioridazine
• Dry mouth, blurred vision, trouble peeing, constipation, fast heartbeat
• It's like your body's automatic systems are struggling—similar to when you're severely dehydrated and everything slows down

Extrapyramidal side effects (movement problems):

• Most common with high-potency FGAs like haloperidol and fluphenazine
• Parkinsonism: trembling at rest, stiff muscles, slow movement—like someone's moving through water
• Dystonia: muscles contracting uncontrollably—imagine your neck suddenly pulling your head to one side
• Akathisia: inner restlessness—that feeling when you've had too much coffee and absolutely cannot sit still
• Tardive dyskinesia: This is the serious one. After long-term use, people develop involuntary movements, usually starting with the tongue, face, and jaw (think repetitive lip-smacking or tongue movements). It can spread to the whole body and may be permanent. More common in women and older adults.

Neuroleptic malignant syndrome (NMS):

• Rare but life-threatening—like your body's temperature regulation just crashes
• Muscle rigidity, high fever, unstable blood pressure, confusion, combativeness
• Requires immediate medical attention and stopping the medication

Second-Generation Antipsychotics (The Upgrade)

The second-generation antipsychotics (SGAs)—also called "atypical" antipsychotics—arrived like the smartphone upgrade that fixed many original problems but introduced new ones. Key drugs: clozapine (Clozaril), risperidone (Risperdal), olanzapine (Zyprexa), and quetiapine (Seroquel).

How they work: SGAs block both dopamine AND serotonin receptors. They're dopamine-serotonin antagonists. The dopamine blocking helps with positive symptoms, while the serotonin blocking may help with negative symptoms and cognitive problems. It's like having two different volume controls instead of just one.

The good news: They're as effective or more effective than FGAs for positive symptoms, and they actually help some with negative symptoms. Clozapine is the only FDA-approved medication for treatment-resistant schizophrenia—when nothing else works, this is the go-to. SGAs also cause fewer movement problems (extrapyramidal side effects).

The trade-off—metabolic syndrome: This is the major concern with SGAs. Think of someone who starts a medication and within months gains 40 pounds, develops pre-diabetes, and their blood pressure shoots up. That's metabolic syndrome, and it includes:

• Significant weight gain
• High blood pressure
• Insulin resistance and high blood sugar
• Increased risk for diabetes and heart disease

It's like the medication trades one set of problems for another. Many clients stop taking these medications because the weight gain feels unbearable—imagine gaining 50 pounds in six months while you're already struggling with your mental health.

The serious risk—blood problems: Clozapine especially can cause a dangerous drop in white blood cells (agranulocytosis), which is why people taking clozapine need regular blood tests. Without enough white blood cells, your immune system is like a security team that's lost most of its staff—you become vulnerable to infections.

Third-Generation Antipsychotics (The Smart Adjusters)

The third-generation antipsychotics (TGAs)—aripiprazole (Abilify), brexpiprazole (Rexulti), and cariprazine (Vraylar)—are the newest approach. Instead of just blocking dopamine, they work more like smart thermostats that adjust based on what's needed in different brain areas.

How they work: TGAs are "dopamine-serotonin stabilizers" and act as partial agonists (which means they both block and activate receptors, depending on the situation):

• In areas where dopamine is too high, they act as blockers (reducing positive symptoms)
• In areas where dopamine is too low, they increase it (helping with negative symptoms and cognition)
• They do similar things with serotonin

Think of them like someone mediating a workplace conflict—they don't just shut people down or amp everyone up. They adjust responses based on what each situation needs.

The advantages: Fewer side effects overall—less likely to cause movement problems, weight gain, or metabolic issues compared to earlier generations.

The downsides: Still can cause akathisia (that restless feeling), plus fatigue, headache, nausea, and anxiety. Interestingly, aripiprazole has been linked to impulse control problems, including compulsive gambling—something to watch for if your client suddenly develops a new gambling habit.

Antidepressants: Five Major Categories

SSRIs: The Go-To First Choice

Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressants. The big names: fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), citalopram (Celexa), and escitalopram (Lexapro).

How they work: SSRIs are like putting a blockade on a recycling system. Normally, your brain releases serotonin, it does its job, then gets recycled back into the neuron that released it. SSRIs block that recycling (reuptake), so more serotonin stays available in the space between neurons. It's an indirect way of increasing serotonin activity.

What they treat: Not just depression—also anxiety disorders (panic disorder, generalized anxiety, social anxiety, OCD, PTSD), premenstrual dysphoric disorder, bulimia, premature ejaculation, and sometimes bipolar disorder (though they need a mood stabilizer partner to prevent triggering mania).

The timeline issue: This is crucial for your clients to understand. SSRIs take 2-4 weeks to start working and 6-8 weeks for full effects. It's like planting seeds—you don't see results immediately. This waiting period is dangerous for severely depressed clients who need to know help is coming but isn't instant.

Common side effects:

• Mild anticholinergic effects (dry mouth, blurred vision)
• Stomach problems
• Insomnia
• Anxiety (ironically, especially at first)
• Sexual dysfunction—this affects both men and women and can include problems with desire, arousal, and orgasm. For some people, this side effect continues even after stopping the medication

Three important complications to know:

Discontinuation syndrome: When someone stops an SSRI suddenly (maybe they run out of pills or just decide to quit), they can experience headaches, dizziness, mood swings, trouble concentrating, sleep problems, and flu-like symptoms. It's not addiction, but the brain doesn't like abrupt changes. Tapering off slowly prevents this.

Serotonin syndrome: This happens when someone takes multiple medications that increase serotonin (like combining an SSRI with an MAOI or too many serotonergic drugs). It's potentially fatal and includes extreme agitation, confusion, fever, tremors, seizures, and delirium. Think of it like flooding an engine—too much of a good thing becomes toxic.

Tachyphylaxis (antidepressant "poop-out"): Picture this: Your medication worked great for months or years, then suddenly stops working despite taking the same dose. That's tachyphylaxis. Signs include apathy, fatigue, foggy thinking, sleep problems, and sexual dysfunction. Solutions include increasing the dose, switching medications, or adding another treatment.

SNRIs: The Two-Chemical Approach

Serotonin and norepinephrine reuptake inhibitors (SNRIs) include venlafaxine (Effexor), duloxetine (Cymbalta), desvenlafaxine (Pristiq), and levomilnacipran (Fetzima).

How they work: Like SSRIs but they block the reuptake of both serotonin AND norepinephrine. It's like adjusting two volume controls instead of one.

What they treat: Depression (particularly severe depression, where they may work better than SSRIs), anxiety disorders, and chronic pain conditions.

Side effects: Similar to SSRIs, including discontinuation syndrome and serotonin syndrome risk. The major addition: Because they affect norepinephrine, they can raise blood pressure. This matters for clients with hypertension or heart problems—like adding extra pressure to a system that's already strained.

NDRIs: The Energizer

Norepinephrine and dopamine reuptake inhibitors (NDRIs) is basically just bupropion (Wellbutrin for depression, Zyban for smoking cessation).

How it works: Blocks reuptake of norepinephrine and dopamine—different neurotransmitters than SSRIs target.

Why it's different: Bupropion has an energizing effect, making it great for clients with low energy and motivation. However, this same quality makes it wrong for clients who are already anxious or have insomnia—like giving coffee to someone who's already jittery.

The advantages:

• Few anticholinergic effects
• No sexual dysfunction (huge selling point)
• Not cardiotoxic
• Helps with smoking cessation

The downsides:

• Skin rash
• Weight loss and decreased appetite
• Agitation and insomnia
• Seizure risk (this is why it's avoided in people with eating disorders, who are at higher seizure risk)

TCAs: The Old Reliable (With Drawbacks)

Tricyclic antidepressants (TCAs) come in two types:

Tertiary amines (affect both serotonin and norepinephrine, stronger on serotonin):

• Amitriptyline (Elavil)
• Imipramine (Tofranil)
• Clomipramine (Anafranil)—especially for OCD
• Doxepin (Sinequan)

Secondary amines (stronger on norepinephrine):

• Nortriptyline (Pamelor)
• Desipramine (Norpramin)

What they treat: Depression, panic disorder, OCD (especially clomipramine), and chronic pain (especially nortriptyline and amitriptyline).

Why they're not first-line anymore: The side effects are rougher than newer medications:

• Cardiovascular effects (blood pressure changes, fast heart rate, dizziness when standing)
• Anticholinergic effects
• Sedation
• Weight gain
• Sexual dysfunction
• Most importantly: They're cardiotoxic and lethal in overdose—this is critical. You don't prescribe TCAs to someone who's actively suicidal because an overdose can kill them.

Important note: TCAs are most likely to trigger mania in someone with bipolar disorder—more than other antidepressants.

Silver lining: Secondary amines have fewer side effects than tertiary amines, and TCAs can be helpful when other medications haven't worked.

MAOIs: The Last Resort With Dietary Rules

Monoamine oxidase inhibitors (MAOIs) include phenelzine (Nardil), isocarboxazid (Marplan), and tranylcypromine (Parnate).

How they work: Your brain has an enzyme called monoamine oxidase that breaks down norepinephrine, serotonin, and dopamine. MAOIs block that enzyme, so those neurotransmitters stick around longer—like preventing the cleanup crew from taking away the decorations.

When they're used: Treatment-resistant depression and "atypical depression" (where someone sleeps and eats MORE than usual, rather than less, and their mood temporarily lifts in response to good things).

The major complication—hypertensive crisis: This is why MAOIs aren't commonly prescribed anymore. MAOIs interact with tyramine (a substance in aged and fermented foods) to cause dangerous blood pressure spikes. Clients need to avoid:

• Aged cheeses and meats
• Soy products
• Beer and red wine
• Sauerkraut
• Fava beans
• Ripe bananas

They also can't take MAOIs with certain medications like amphetamines or antihistamines.

Signs of hypertensive crisis: Severe throbbing headache, neck pain/stiffness, rapid heart rate, nausea, vomiting, sweating, light sensitivity, confusion. This is a medical emergency.

Imagine telling a client with depression—who's already struggling with daily functioning—that they need to strictly monitor everything they eat and drink, check every medication, and carry a list of restrictions. That's why MAOIs are reserved for cases where other treatments have failed.

Comparison Table: Antipsychotic Generations

Comparison Table: Major Antidepressants

Common Misconceptions Students Get Wrong

"Antipsychotics only treat psychosis" Wrong. These medications are used for bipolar disorder, major depression (as add-ons), OCD, and more. Don't let the name fool you.

"Antidepressants work immediately" Nope. It takes 2-4 weeks minimum, often 6-8 weeks for full effect. This is a dangerous misconception because clients might give up or think nothing's working when they're actually on the right track.

"Newer medications are always better" Not necessarily. While third-generation antipsychotics and SSRIs have fewer side effects for many people, older medications like TCAs and clozapine can be more effective for some clients. It's about matching the right medication to the right person.

"Psychologists don't need to know medications in detail" This is the biggest mistake students make. You'll be monitoring your clients' symptoms, noticing side effects before the prescriber does, and helping clients understand what's happening. Your observations can literally save lives.

"Discontinuation syndrome is withdrawal/addiction" Discontinuation syndrome isn't addiction—these medications aren't habit-forming in that sense. It's your brain adjusting to the absence of medication it's been using to regulate neurotransmitters. Important distinction for clients who worry about becoming "addicted."

Memory Tricks for the EPPP

For antipsychotic generations:

• 1st Gen = 1 target = Dopamine only (D2 blockers)
• 2nd Gen = 2 targets = Dopamine AND Serotonin (antagonists for both)
• 3rd Gen = Smart/Stable (partial agonists that stabilize)

For side effect patterns:

• Low potency FGAs = "Anti-C" (anticholinergic effects)
• High potency FGAs = "Extra-P" (extrapyramidal effects)
• SGAs = "Meta-weight" (metabolic syndrome and weight gain)

For antidepressants, count the letters:

• SSRI = Serotonin only (one neurotransmitter)
• SNRI = Serotonin + Norepinephrine (two neurotransmitters)
• NDRI = Norepinephrine + Dopamine (different two)

For MAOI dangers:

• "Old WINE and old CHEESE will RAISE your BP" (tyramine + MAOI = hypertensive crisis)

For potentially fatal reactions:

• NMS (Neuroleptic Malignant Syndrome) = starts with N like neuroleptics (antipsychotics)
• Serotonin Syndrome = starts with S like SSRIs and SNRIs

Real-World Application: What This Looks Like in Practice

You're seeing Marcus, a 28-year-old with depression, for weekly therapy. He tells you his psychiatrist started him on Zoloft (sertraline, an SSRI) two weeks ago, and he's frustrated because "it's not working." You explain the 6-8 week timeline and help him track symptoms to show progress.

Three months later, Marcus mentions he's been having trouble with his sex life since starting the medication but was too embarrassed to tell his psychiatrist. You normalize this extremely common side effect and encourage him to discuss it with his prescriber—there are several solutions, including switching to Wellbutrin or adding medications that can help.

Or consider Jasmine, a 35-year-old with schizophrenia taking Zyprexa (olanzapine, an SGA). She's gained 35 pounds in four months and is devastated. She tells you she's thinking about stopping her medication because she "can't stand what it's doing" to her body. You empathize with her distress while helping her understand the risks of stopping abruptly. You collaborate with her prescriber to discuss alternatives—maybe switching to a TGA like Abilify, which has lower metabolic risks, or adding medications to manage the weight gain.

These are the moments where your medication knowledge matters. You're not prescribing anything, but you're the professional who sees clients weekly, who notices the subtle changes, who clients trust with the embarrassing details they won't tell anyone else.

Key Takeaways

Antipsychotics:

• Three generations with different mechanisms and side effect profiles
• FGAs (typical): Dopamine blockers, good for positive symptoms, high risk of movement problems
• SGAs (atypical): Block dopamine and serotonin, help negative symptoms too, metabolic syndrome risk
• TGAs: Stabilizers/partial agonists, balance neurotransmitters, fewer overall side effects
• Know the serious risks: tardive dyskinesia, NMS, agranulocytosis, metabolic syndrome

Antidepressants:

• SSRIs are first-line: safest, most common, but take weeks to work and cause sexual dysfunction
• SNRIs add norepinephrine: good for severe depression and pain but watch blood pressure
• Bupropion (NDRI): energizing, no sexual side effects, avoid with anxiety/insomnia
• TCAs: effective but dangerous in overdose, rough side effects, older medication
• MAOIs: last resort with dietary restrictions, risk of hypertensive crisis

Critical safety knowledge:

• Antidepressants take 2-4 weeks minimum to work (6-8 for full effect)
• Never stop SSRIs/SNRIs abruptly (discontinuation syndrome)
• Never combine serotonergic drugs without medical supervision (serotonin syndrome)
• TCAs are lethal in overdose—matters for suicidal clients
• MAOIs require dietary restrictions—can't eat tyramine-containing foods
• Antidepressants can trigger mania in bipolar disorder (TCAs are highest risk)

For the EPPP:

• Know generic names (exam uses these more than brand names)
• Understand mechanisms of action (what neurotransmitters each drug affects)
• Recognize side effect patterns by drug class
• Remember which medications treat which conditions
• Know the serious/life-threatening side effects for each category

Your knowledge of psychopharmacology makes you a better, safer clinician. When you understand what your clients are taking, you become an essential part of their treatment team—noticing changes others might miss and advocating for adjustments when needed. This isn't just exam material. It's how you protect the people who trust you with their care.