Seroquel Drug Class: Uses, Schedule, and Potential for Abuse

What Drug Class Is Seroquel?

Seroquel (quetiapine) belongs to the atypical antipsychotic drug class. It is not a controlled substance. The DEA does not schedule it. But misuse of Seroquel has increased steadily since 2020, particularly in correctional facilities and among people with substance use disorders.

Quetiapine works by blocking dopamine D2 and serotonin 5-HT2A receptors in the brain. At low doses (25 to 100 mg), it acts primarily as an antihistamine, producing strong sedation. At higher doses (300 to 800 mg), its antipsychotic and mood-stabilizing effects emerge.

Fast Facts About Seroquel

• Drug class: Atypical (second-generation) antipsychotic
• Schedule: Not a controlled substance federally or in any state
• FDA-approved uses: Schizophrenia, bipolar disorder, major depressive disorder (as adjunct therapy)
• Common off-label uses: Insomnia, anxiety, PTSD-related sleep disturbance
• Street names: Quell, Susie Q, baby heroin, squirrel

FDA-Approved Uses

Schizophrenia

Quetiapine received FDA approval for schizophrenia in 1997. Standard dosing ranges from 150 to 750 mg daily. It reduces hallucinations, delusions, and disorganized thinking.

Bipolar Disorder

Approved for acute manic episodes, depressive episodes, and maintenance therapy. The extended-release formulation (Seroquel XR) is preferred for bipolar depression at 300 mg daily.

Major Depressive Disorder

FDA approved as add-on therapy for depression that does not respond to antidepressants alone. Dosing for this indication is typically 150 to 300 mg daily.

Off-Label Prescribing

Quetiapine is one of the most commonly prescribed off-label medications in the US. Studies show that over 50% of Seroquel prescriptions are written for off-label uses, primarily insomnia and anxiety. Low-dose quetiapine (25 to 50 mg) exploits its antihistamine properties for sleep without activating its antipsychotic mechanism.

The American Academy of Sleep Medicine does not recommend quetiapine as a first-line insomnia treatment due to its metabolic side effects. Cognitive behavioral therapy for insomnia (CBT-I) remains the gold standard.

How Seroquel Gets Misused

People misuse Seroquel for several reasons:

1. Self-medication for insomnia: The strong sedation makes it appealing as a sleep aid, especially for people in withdrawal from stimulants or alcohol.
2. Enhancing other drugs: Taken with opioids or benzodiazepines to intensify sedation.
3. Coming down from stimulants: Used to counteract cocaine or methamphetamine stimulation.
4. Correctional facility use: Seroquel is one of the most traded medications in jails and prisons, where controlled substances are harder to obtain.

Abuse Data

The FDA’s Adverse Event Reporting System (FAERS) logged over 28,000 quetiapine misuse reports between 2004 and 2023. Poison control centers receive thousands of calls annually about quetiapine overdoses. In 2022, the Drug Abuse Warning Network recorded quetiapine in 33,000 emergency department visits.

Side Effects and Health Risks

Even at prescribed doses, quetiapine carries significant side effects:

• Weight gain: Average weight gain of 5 to 10 pounds in the first year. Quetiapine blocks histamine H1 receptors, increasing appetite.
• Metabolic syndrome: Increased risk of type 2 diabetes, high cholesterol, and high blood pressure.
• Sedation: Drowsiness is the most common side effect, affecting over 50% of users.
• Orthostatic hypotension: Blood pressure drops upon standing, causing dizziness and falls.
• Tardive dyskinesia: Involuntary muscle movements with long-term use (rare but permanent).

Seroquel Withdrawal

Stopping quetiapine abruptly after prolonged use causes withdrawal symptoms. These include insomnia, nausea, vomiting, headaches, dizziness, and irritability. Psychotic symptoms (hallucinations, paranoia) may rebound in people who take quetiapine for schizophrenia or bipolar disorder.

Tapering over 2 to 4 weeks under medical supervision prevents most withdrawal effects.

Talk to Your Prescriber

If you use Seroquel for sleep and want to explore alternatives, talk to your doctor about CBT-I, melatonin, or other sleep hygiene strategies. If you use Seroquel recreationally, treatment programs address the underlying issues driving substance misuse. Call SAMHSA at 1-800-662-4357 for free, confidential referrals.