Trazodone is FDA-approved to treat major depressive disorder in adults, but its most common use today is actually for something else: insomnia. Off-label prescribing for sleep problems has surpassed its use as an antidepressant, making it one of the most widely prescribed sleep aids in the United States.
Depression: The FDA-Approved Use
Trazodone was approved in 1982 as an antidepressant. It works differently from the more commonly prescribed SSRIs. Rather than just blocking serotonin from being reabsorbed (which is what SSRIs do), trazodone also blocks specific serotonin receptors that can cause side effects like sexual dysfunction, anxiety, and sleep disruption. This dual action means it can relieve depression while avoiding some of the tolerability issues that come with other antidepressants.
For depression, the typical starting dose is 150 mg per day taken in divided doses, with gradual increases of 50 mg every three to four days if needed. Outpatients generally stay at or below 400 mg per day. Like most antidepressants, trazodone takes several weeks of consistent use before its full mood-lifting effects kick in. It can be used on its own or combined with other medications or psychotherapy.
Insomnia: The Most Common Use
The reason trazodone became so popular as a sleep aid comes down to how it interacts with the brain at low doses. Even a tiny amount, around 1 mg, blocks about half of the brain’s serotonin receptors involved in wakefulness. At slightly higher doses (around 50 mg), it also blocks histamine and adrenaline receptors, both of which play a role in keeping you alert. The combined effect of quieting all three of these systems produces reliable drowsiness.
The doses used for sleep are much lower than those used for depression, typically 25 to 100 mg taken about 30 minutes before bedtime. At these doses, trazodone has a short half-life of three to six hours, which is long enough to help you fall and stay asleep but short enough to clear your system by morning. This means less grogginess the next day compared to many other sleep medications. It also doesn’t appear to cause tolerance, so you’re unlikely to need a higher dose over time to get the same effect.
The evidence behind this use is substantial. A systematic review examining 45 studies found that 95.5% of them concluded trazodone was effective for insomnia. It works for people whose sleep problems stand alone (primary insomnia) and for those whose insomnia stems from another condition like depression or dementia. In one controlled trial, 50 mg taken at bedtime improved sleep maintenance in adults. In a larger study of 549 patients, a controlled-release version produced significant improvements over six weeks.
Trazodone also helps regulate the body’s stress hormone system, which likely contributes to its sleep benefits. Stress hormones that stay elevated at night are a common driver of insomnia, and trazodone appears to moderate that response.
Anxiety and Agitation in Dementia
Trazodone is also prescribed off-label for behavioral and psychological symptoms in people with dementia. These symptoms, including agitation, anxiety, and sleep disruption, are among the most distressing aspects of dementia for both patients and caregivers. In clinical practice, trazodone is used at relatively low doses (averaging around 75 mg, ranging from 25 to 300 mg) to manage these symptoms. It’s chosen partly because it has minimal anticholinergic effects, which is important because drugs with strong anticholinergic activity can worsen confusion and cognitive decline in older adults.
The evidence here is more limited than for insomnia. Prescribing data from dementia clinics shows that trazodone is used most often for behavioral disturbance and insomnia in this population, with anxiety and depression as secondary targets. Patients who receive trazodone tend to have more severe neuropsychiatric symptoms than those who don’t, which reflects its role as a tool for managing difficult-to-treat behavioral issues.
How It Compares to Other Antidepressants
Trazodone belongs to a class called serotonin antagonists and reuptake inhibitors, or SARIs. This sets it apart from SSRIs and SNRIs in a clinically meaningful way. SSRIs boost serotonin activity across all serotonin receptor types, which is why they can cause side effects like insomnia, sexual dysfunction, and anxiety, especially early in treatment. Trazodone boosts serotonin in some pathways while simultaneously blocking the receptor subtypes responsible for those particular side effects.
This profile makes trazodone especially useful for people who have depression with prominent insomnia, or for those who’ve had trouble tolerating other antidepressants. It’s sometimes added to an existing antidepressant specifically to counteract sleep disruption caused by that medication.
Side Effects to Know About
Trazodone’s side effects are dose-dependent. Drowsiness is the most common, which is a drawback when treating depression but the entire point when treating insomnia. Other common effects include dizziness, nausea, and headaches.
A more significant concern, particularly for older adults, is a drop in blood pressure when standing up. This happens because trazodone blocks adrenaline receptors that help maintain blood pressure during position changes. The effect is usually temporary and more pronounced at higher doses, but it can increase the risk of fainting and falls. One study of older adults with high blood pressure found that 58% of those taking trazodone experienced fainting or falls, compared to 21% of those not taking the medication. Using lower doses or extended-release formulations can reduce this risk.
A rare but serious side effect in men is priapism, a prolonged, painful erection unrelated to sexual arousal. This occurs in roughly 1 in 1,000 to 1 in 10,000 users and requires immediate medical attention.
Stopping Trazodone Safely
Trazodone should not be stopped abruptly, especially after long-term use. Discontinuation can cause withdrawal symptoms including anxiety, irritability, dizziness, nausea, headaches, fatigue, rebound insomnia, sweating, and mood swings. The typical approach is a gradual taper, reducing the dose by 10% to 25% per week. Someone taking 150 mg, for example, might drop to 125 mg or 100 mg in the first week and continue stepping down from there over several weeks or months.