While these drugs play a critical role in managing depression and other mood disorders, their influence on sleep can sometimes complicate treatment.

Antidepressants primarily function by altering the levels of key brain chemicals such as serotonin, norepinephrine, and dopamine.

These neurotransmitters not only influence mood but also play significant roles in regulating sleep-wake cycles. When their balance is shifted, either through medication or underlying depression, it can affect sleep architecture.

Sleep architecture refers to the stages your body cycles through during the night, including:

  • light sleep
  • deep sleep
  • REM (rapid eye movement) sleep

Each stage serves specific functions that contribute to mental restoration, memory consolidation, and physical health.

Antidepressants may disrupt this cycle, leading to lighter, more fragmented sleep, or difficulty staying asleep.

Not all antidepressants impact sleep the same way. Some are more likely to cause insomnia, particularly those that increase alertness or stimulate certain areas of the brain.

Selective serotonin reuptake inhibitors (SSRIs)

SSRIs are widely prescribed for depression. Examples include:

These medications boost serotonin levels, which can help improve mood. However, they may also increase alertness and interfere with your ability to fall or stay asleep.

Serotonin-norepinephrine reuptake inhibitors (SNRIs)

Medications in this class also enhance norepinephrine levels. Examples include:

This added stimulation can result in insomnia, particularly if taken later in the day.

These medications may reduce both deep sleep and REM sleep duration, contributing to a less restorative sleep experience.

Bupropion (Wellbutrin)

Bupropion affects dopamine and norepinephrine and is considered more activating than other antidepressants.

While it may be beneficial for individuals experiencing fatigue or low motivation, it carries a higher risk of insomnia, especially if taken in the afternoon or evening.

Newer medications

Vilazodone (Viibryd) and vortioxetine (Trintellix) are newer antidepressants that vary in their impact on sleep. Vilazodone has shown a higher risk of insomnia, while vortioxetine appears to pose less risk for either insomnia or excessive sleepiness, based on recent clinical data.

Some antidepressants have sedative properties and are sometimes used off-label to manage insomnia, especially in people who experience it alongside depression.

Trazodone

Originally developed as an antidepressant, trazodone is commonly used for sleep due to its sedating effects. It is often prescribed at lower doses for insomnia, though its effectiveness and safety as a long-term solution remain debated.

Mirtazapine (Remeron)

Mirtazapine increases serotonin and norepinephrine but also acts on histamine receptors, which contributes to its sedative effects. It’s often prescribed for people who have depression along with insomnia or anxiety.

However, at higher doses, its sedative effect may diminish, and side effects like restless leg syndrome may appear.

Amitriptyline

Though not officially approved for insomnia, amitriptyline, a tricyclic antidepressant, has shown a lower risk of insomnia and a higher likelihood of causing drowsiness.

Its use for sleep disorders is common in clinical practice, despite limited evidence supporting its effectiveness in treating insomnia directly.

A 2023 study examined data from 216 randomized controlled trials, covering over 64,000 people.

It found that 11 antidepressants significantly increased the risk of insomnia, with reboxetine, vilazodone, and desvenlafaxine showing the highest odds.

At the same time, several antidepressants were linked to excessive sleepiness, or somnolence. Fluvoxamine, trazodone, and mirtazapine had the strongest associations with sleepiness.

This dual risk — some drugs promoting insomnia, others causing excessive drowsiness — illustrates how complex the relationship between antidepressants and sleep can be.

The study also emphasized that the relationship between dosage and sleep effects is not always straightforward.

For some drugs, the risk of insomnia increases significantly only at higher doses. For others, the risk plateaus or follows a non-linear pattern.

This makes it essential to evaluate both the type and dosage of antidepressants when addressing sleep concerns.

If you’re experiencing insomnia while taking an antidepressant, there are several steps you can take to manage it.

Speak with your prescriber

Never stop or change your medication without consulting your healthcare professional.

They can help determine whether your symptoms are medication-related and discuss potential adjustments, such as changing the dosage, switching to a different antidepressant, or altering the time of day you take your medication.

Monitor dosage carefully

Some medications may cause insomnia only at certain dosages. Your healthcare professional may recommend a lower dose or a gradual adjustment to minimize side effects.

Consider alternatives

If insomnia persists, switching to an antidepressant with sedative properties — such as trazodone, mirtazapine, or amitriptyline — may be an option.

These can offer relief from both depression and sleep disruption, although they may come with other side effects.

Practice sleep hygiene

Incorporating sleep-friendly habits into your routine can complement your treatment. For example:

  • Go to bed and wake up at consistent times
  • Avoid caffeine late in the day
  • Reduce screen time before bed
  • Create a relaxing bedtime environment

Explore non-medication therapies

Cognitive behavioral therapy for insomnia (CBT-I) is an established treatment that can help retrain your brain for better sleep.

It’s a highly recommended option, particularly when sleep symptoms persist despite medication adjustments.

Antidepressants can both alleviate and disrupt sleep, depending on the specific drug, dosage, and your individual response.

If insomnia is interfering with your treatment or daily functioning, it’s important to consult a healthcare professional. They can help you develop a strategy that supports your mental health and your rest.