Antidepressants For Sleep

Are you aware that sometimes medical experts prescribe antidepressants as sleep aids? However, there is some controversy about using these medications to induce sleep, as they are not licensed to treat sleep problems. 

Some antidepressants given in low doses, can have a sedative effect. Hence, they are one of the medications used to treat insomnia. However, if you aren’t diagnosed with depression, you should avoid taking them as a sleeping aid, as their effect is short-term and can even cause side effects.¹

This article aims to explain what antidepressants are used as sleep inducers, how they work, their possible side effects, and other alternatives to achieve sleep. 

What are antidepressants?

Antidepressants are medications that are prescribed to treat depression or other conditions like generalised anxiety disorder (GAD) or post-traumatic stress disorder (PTSD).

While there are a wide range of these medicines, they can be classified into the following categories:

• Selective Serotonin Reuptake Inhibitors (SSRIs)
• Serotonin-Noradrenaline Reuptake Inhibitors (SNRIs)
• Tricyclic Antidepressants (TCAs)
• Noradrenaline and Specific Serotonergic Antidepressants (NASSAs)
• Monoamine Oxidase Inhibitors (MAOIs)

What are sleep disorders?

Sleep disorders are disturbances in the quality, timing and amount of sleep you get. Sleep deprivation will cause you to feel tired and distressed, and it will also negatively impact your functioning. The most common sleep disorder is insomnia. If you have trouble sleeping, it could be due to a combination of physical and mental issues, including:

• Depression
• Side effects of antidepressants or other medications
• Anxiety
• Stress
• Caffeine
• Noises
• Alcohol consumption
• Chronic pain

The link between antidepressants and sleep

Antidepressants can impact sleep: while some can deteriorate sleep quality and make it harder to fall asleep, others have a drowsing effect, like it is the case of sedating TCAs (e.g., Doxepin) or Trazadone.² 

The sedating TCAs act as histamine-1 (H₁) receptor blockers. These receptors are distributed through the central nervous system and especially concentrated in areas of the brain that are involved in facilitating wakefulness. This happens when the receptor is activated by agonists. Consequently, if you take a TCA, your H₁ receptors will be blocked, so you will experience sleepiness.³

On the other hand, antidepressants in the serotonin antagonists and reuptake inhibitors (SARIs) category, like Trazodone, inhibit the 5-HT2 receptors. Serotonin (5-HT) is a neurotransmitter that contributes to wakefulness. There are several subcategories of 5-HT receptors. It seems that by blocking the 5-HT2 group with the antidepressant Trazodone, your brain sends a signal to increase slow wave sleep (SWS), and you don’t wake up as much after falling asleep. Furthermore, research indicates that if you take a dose, ranging from 25mg to 100mg, of the mentioned SARI, it can also block H₁ receptors and α1 adrenergic receptors simultaneously, which further promotes sleep and staying asleep.⁴

Hence, it is important you check which antidepressants cause insomnia and which have a sedative impact. If you are taking antidepressants like venlafaxine or fluoxetine, and you find yourself unable to sleep, understand it’s due to the medication's side effects.² In this case, discuss it with your general practitioner or your psychiatrist so they prescribe you alternative treatments that won’t interfere with your sleep. 

Antidepressants as sleeping aids

Not all the antidepressants will have a sedative effect. Here is a list of these medications that are used as sleeping aids: ^1,2

• Amitriptyline
• Dosulepin
• Doxepin
• Trazodone
• Mirtazapine
• Mianserine
• Nefazodone

Please, remember that this is only informative, and you should discuss this with a medical expert.

Considerations and precautions of using antidepressants for sleep

Here are some things you should consider if you are taking antidepressants as sleeping medications:

• Doxepin (a sedative TCA) is the only antidepressant that is actually approved as a treatment for insomnia by the US Food and Drug Administration (FDA). Other antidepressants with sedative effects are prescribed off-label, with lower doses than the recommended doses for depression 
• There is limited evidence that supports that antidepressants should be used to treat insomnia, and there are few long-term studies following the action of these medications for sleep^1,2 
• It also appears that the duration of the sedative effect of these medications is shorter compared to other sleep aids¹ 
• Antidepressants, like any other drugs, have side effects, so if you are taking them as a sleeping medication, you could also be experiencing: constant sleepiness during the day, headaches, dizziness, nausea, further sleep impairment, nightmares, weight fluctuations, restless legs syndrome, and drowsiness^1,2 
• If you are being treated for depression or other coexisting conditions, check with a medical expert that your medications are compatible and it is not dangerous to take them together
• Different individuals will require different doses of these medications to achieve sleep. Your general practitioner should monitor you during the treatment, and adjust your doses depending on the improvement of your sleep, your tolerance, and any possible side effects you might be experiencing 
• Once again, low doses of these medicines are recommended for sleep issues, however, consider that different antidepressants will have different effectiveness on your body, so the quantity will also depend on the specific medication you are prescribed 

Alternative approaches

Using antidepressants to regulate sleep might not be the best approach for this situation. Here are some alternatives that you could try instead:

• Cognitive-Behavioural Therapy for Insomnia (CBT-I)
• Melatonin supplements
• Exercise regularly
• Avoid consuming caffeine close to bed-time
• Ensure your room is dark and quiet
• Consult a medical expert for other medical sleeping aids

FAQ’S

Are there other prescriptions that work as sleep aids?

Yes, there are different sleep medications that your general practitioner could prescribe you, including melatonin agonists, benzodiazepines, benzodiazepine agonists, and dual orexin receptor antagonists (DORAs). Your GP will prescribe you the option that is more suitable for you.

How many mg of the sedative antidepressant should I take to achieve sleep?

As previously mentioned, the dose of medication will depend on the person and type of antidepressant. Moreover, this is something that your GP should advise you on. Please follow their instructions, and don’t try to self-medicate as it could not only be dangerous, but it could also have a negative impact on your health.

When is the best time to take a sedative antidepressant for insomnia?

This will probably depend on which medication you are taking, so you should consult an expert or read the prospect. However, you should take it before you go to bed so you can fall asleep easier.

Summary

Antidepressants are medications commonly prescribed to treat depression, and can also be used as sleeping aids to treat insomnia. Being well rested is important to feel good and function properly. Sometimes experts recommend these medications to facilitate sleep due to the sedative effect some of these have. It is important to know which antidepressants can induce sleep, as some of these medicines have the opposite effect. For instance, some tricyclic antidepressants facilitate sleepiness because they block H1 receptors, which contribute to being awake. In addition, antidepressants in the serotonin antagonists and reuptake inhibitors category are also used to treat insomnia because they contribute to achieving the deep sleep phase of your sleep cycle and help maintain your sleep. While these medications have been used for a while to deal with sleep disturbances, only Doxepin is approved for this purpose. Meanwhile, the other sedating antidepressants are considered off-label. Experts also recommend using a low dose of these medications (below the recommended threshold to treat depression). However, research is quite limited, and more studies are needed to determine their effectiveness over a long-term period, possible interactions with other medications, and other concerns. Furthermore, if you are having trouble sleeping, you should consider other alternatives like cognitive-behavioural therapy for insomnia, exercising, meditation, or other types of prescriptions recommended by an expert.