I’ve Been Prescribed an Antidepressant, What Should I Expect
Being prescribed an antidepressant can bring mixed feelings. You may feel hopeful that something might help, worried about side effects, uncertain about taking medication, or simply unsure what happens next.
Being prescribed an antidepressant can bring mixed feelings. You may feel hopeful that something might help, worried about side effects, uncertain about taking medication, or simply unsure what happens next.
Antidepressants are prescription medicines used for depression and some other mental-health conditions. Being prescribed one does not tell you how severe your difficulties are, how long you will need treatment or exactly how you will respond.
Those are individual clinical questions for the healthcare professional looking after you.
The prescription is the beginning of a treatment conversation
NICE recommends that people starting antidepressants are given information about why medication is being offered, possible benefits and harms, side effects, withdrawal effects, how the medicine should be taken and when treatment will be reviewed.
That means it is reasonable to ask questions.
You might want to understand why this type of medicine has been suggested, what improvement you and your clinician are looking for, what side effects you should know about and when you will next speak to someone about how things are going.
Improvement is not necessarily immediate
Antidepressants do not usually produce their intended benefit as soon as the first dose is taken.
NICE says that, where an antidepressant is going to work, an effect is usually seen within about four weeks. NHS information also explains that antidepressants can take time to have their full effect.
This is general information, not a timetable for your own treatment. Your prescriber can explain what is reasonable to expect from the particular medicine you have been given.
You may notice unwanted effects as well as hoped-for benefits
Antidepressants can cause side effects, and the type and severity vary between medicines and between people.
Some people experience few difficulties. Others notice effects that are uncomfortable or concerning.
Rather than trying to decide from a general webpage whether an effect is normal, speak to your pharmacist, GP or prescriber if you are worried. They can consider the actual medicine, your health, other medication and the symptoms you describe.
Reviews are part of treatment
Starting medication should not mean receiving a prescription and then being left to work everything out yourself.
NICE recommends follow-up after antidepressants are started, with timing depending on individual circumstances and clinical risk.
A review gives you an opportunity to describe changes in mood, everyday functioning, side effects and concerns. If you do not know when your medication is due to be reviewed, ask the service or professional who prescribed it.
Keep a simple record if it helps you explain what is happening
You do not need to monitor every feeling throughout the day.
But a brief note of changes in sleep, mood, anxiety, concentration, everyday functioning or unwanted effects can make a later conversation easier.
The purpose is not to diagnose yourself or decide whether to change medication. It is to give your healthcare professional clearer information about your experience.
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.