What Are the Different Types of Antidepressants
“Antidepressant” describes a group of medicines rather than one single treatment.
“Antidepressant” describes a group of medicines rather than one single treatment.
There are several classes of antidepressant. They differ in how they affect chemical signalling, their side-effect profiles, interactions and the circumstances in which clinicians may consider them.
Knowing the class name can help you understand information about your prescription. It should not be used to choose a medicine for yourself.
SSRIs
Selective serotonin reuptake inhibitors, usually shortened to SSRIs, are one class of antidepressant.
They affect serotonin signalling and are widely used in mental-health treatment.
Whether an SSRI is appropriate for a particular person is a prescribing decision. Other health conditions, other medicines, previous treatment and individual risks and preferences can all matter.
SNRIs
Serotonin and noradrenaline reuptake inhibitors, or SNRIs, are another class.
They affect serotonin and noradrenaline signalling.
Although SSRIs and SNRIs are often discussed together, they are not interchangeable. Their effects, side effects, interactions and withdrawal considerations can differ.
Other antidepressant groups
Other types include tricyclic antidepressants and monoamine oxidase inhibitors, as well as antidepressants that do not fit neatly into those groups.
Some are used less commonly or in particular clinical circumstances.
A longer list does not help somebody decide which treatment they need. That requires an individual assessment by an appropriately qualified prescriber.
Why might two people be prescribed different medicines?
The same diagnosis does not automatically lead to the same prescription.
NICE guidance emphasises shared decision-making and consideration of matters such as likely benefits, possible harms, side effects, other illnesses or medicines, previous treatment and the person’s concerns and preferences.
This is one reason comparing your prescription with somebody else’s can be misleading.
Class names do not predict your personal experience
Knowing that a medicine is an SSRI, SNRI or another type can help you understand general information.
It cannot tell you whether you will experience a particular side effect, how well the medicine will work for you or how long you should take it.
Those questions belong in a conversation with your GP, prescriber or pharmacist.
Last reviewed
6 September 2026
Important medication and mental health information
This guide provides general information only and is not medical advice. It is not intended to recommend any particular medicine, treatment, dose, change to medication or course of action.
Medicines can affect people differently. The appropriate treatment will depend on your individual circumstances, health, other medicines you take and the reason treatment has been prescribed.
Do not start, stop, reduce, increase, change or switch prescribed medication based on information in this guide. If you have questions or concerns about your medication, side effects, missed doses, withdrawal symptoms or whether treatment is helping, speak to your GP, prescribing clinician, pharmacist or another appropriately qualified healthcare professional.
If you think you may be experiencing a serious reaction to medication, seek urgent medical advice.
If you or somebody else is in immediate danger or there is a life-threatening emergency, call 999 or go to A&E. If you are experiencing a mental health crisis and need urgent help but it is not a life-threatening emergency, contact NHS 111 and select the mental health option, or use your local NHS urgent mental health service.