Antidepressant Side Effects, What Should I Know
Antidepressants can cause side effects, but a list of every possible effect can sometimes create more anxiety than understanding.
Antidepressants can cause side effects, but a list of every possible effect can sometimes create more anxiety than understanding.
The important starting point is that side effects vary between medicines and between people. Some people have few problems. Some experience effects that settle. Others have side effects that need discussion with the healthcare professional responsible for their treatment.
A general MH360 guide cannot tell you whether a symptom is caused by your medication.
Common does not mean inevitable
Medicine information often describes effects as common, uncommon or rare.
Those words describe how often something has been reported or observed; they do not predict what will happen to you.
Do not assume you will experience an effect because you have read about it, and do not dismiss something concerning simply because it is not on a short list.
Side effects can involve different parts of everyday life
Depending on the antidepressant, reported effects can involve sleep, digestion, headaches, dizziness, tiredness, restlessness, sweating or sexual functioning, among other things.
The exact profile differs between medicines.
For information about your prescription, use the patient information supplied with it and speak to your pharmacist, GP or prescriber if anything is unclear.
The timing matters, but it does not provide a diagnosis
A symptom that appears after starting a medicine may make you wonder whether the two are connected.
Timing is useful information for your clinician, but it is not proof. Physical illness, anxiety, other medicines and unrelated health problems can produce similar symptoms.
Tell your healthcare professional what happened, when it started and how it is affecting you.
Do not solve side effects by changing the prescription yourself
If an unwanted effect is bothering you, the appropriate response depends on the medicine, the effect, its severity and your wider health.
Do not skip doses, alter the amount, stop suddenly or use somebody else’s medication advice as a substitute for your own clinical guidance.
Speak to your pharmacist, GP, prescribing clinician or another appropriately qualified healthcare professional.
Know when to seek urgent help
Some reactions to medicines can be serious.
This guide cannot provide a complete symptom-by-symptom emergency checklist for every antidepressant. Read the information supplied with your medicine and seek urgent medical advice if you think you may be having a serious reaction.
If there is a life-threatening emergency or somebody is in immediate danger, call 999 or go to A&E.
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.