On this page
- The most important point
- Four medicines you may commonly hear about
- A little more about each medicine
- What about escitalopram, duloxetine or venlafaxine?
- Tell the prescriber before choosing a medicine
- Side effects are part of the choice—not an afterthought
- Questions worth asking
- Starting, changing and stopping safely
- Evidence and official guidance
Antidepressants are a family of medicines rather than one treatment. Several can be effective, but they differ in their side effects, interactions and how they may feel to take. This guide explains some of the medicines commonly considered in primary care.
The most important point
There is no medicine that is best for everyone. NICE recommends choosing treatment together, taking account of previous response, other health conditions and medicines, suicide risk, pregnancy or breastfeeding, and preferences about effects such as sleepiness, sexual side effects or weight change.
Selective serotonin reuptake inhibitors—usually shortened to SSRIs—are often considered first because they are generally well tolerated and have a good safety profile. A medicine that helped you or a close relative before may also influence the discussion.
Four medicines you may commonly hear about
An SSRI used for depression and several anxiety-related conditions, including panic disorder, OCD, PTSD and social anxiety. Early nausea, diarrhoea, headache, sleep change or increased anxiety can occur; sexual side effects are also possible.
An SSRI used for depression and panic disorder. It is often straightforward to take, but it can affect the heart’s electrical rhythm in some people, so age, heart health, dose and other medicines need consideration.
An SSRI used for depression, OCD and bulimia. Some people experience it as more activating, so sleep disturbance or restlessness may matter. It stays in the body longer than many antidepressants and has some important medicine interactions.
A different type of antidepressant, usually taken at night because it can cause sleepiness. It may be considered when poor sleep or low appetite are prominent, but increased appetite, weight gain and morning drowsiness can be important disadvantages.
A little more about each medicine
Often used when depression sits alongside anxiety, panic, OCD or PTSD. Common effects listed by the NHS include nausea, diarrhoea, headache, dizziness or drowsiness, sleep problems and sexual difficulties. It can interact with blood thinners, anti-inflammatory painkillers and other medicines, so a medication check is important.
Another commonly used SSRI. Nausea, headache, dry mouth, sweating, sleep changes and sexual difficulties may occur. Citalopram can prolong the QT interval—the timing of the heartbeat—so it may not suit some people with heart problems or those taking certain other medicines. An ECG is sometimes needed.
Fluoxetine may feel more activating for some people, although individual responses vary. Nausea, headache, sleep disturbance, weight change and sexual difficulties can occur. Because it remains in the body for longer, interactions and any later switch to another antidepressant need careful planning.
Mirtazapine commonly causes drowsiness and is usually taken before bed. Increased appetite and weight gain can occur. Some people value the sedating effect when sleep is very poor; others find morning drowsiness or appetite change makes it a poor fit.
What about escitalopram, duloxetine or venlafaxine?
Escitalopram is closely related to citalopram and is another SSRI. Duloxetine and venlafaxine are serotonin and noradrenaline reuptake inhibitors, or SNRIs. These medicines may be considered because of previous response, another condition or when an initial treatment has not helped enough.
SNRIs can affect blood pressure and may have more troublesome withdrawal effects for some people—particularly venlafaxine—so review, regular dosing and gradual reduction are important. More complex switching or combinations may need specialist advice.
Tell the prescriber before choosing a medicine
Mention pregnancy or breastfeeding; heart disease; epilepsy; glaucoma; diabetes; bleeding problems; liver or kidney disease; bipolar disorder or past periods of unusually high energy and reduced need for sleep; and any previous serious reaction.
Bring a complete list of prescribed medicines, over-the-counter painkillers, supplements and recreational drugs. St John’s wort can interact seriously with antidepressants and should not be combined without professional advice.
Side effects are part of the choice—not an afterthought
People value different things. One person may particularly want to avoid sedation because they drive for work; another may be most concerned about sexual side effects, weight change or worsening insomnia. Say what matters to you before treatment starts.
Side-effect lists describe possibilities, not certainties. Many people have mild or temporary effects, while others need a change. Contact the prescriber or pharmacist if an effect is troubling, persistent or unexpected.
Questions worth asking
- Why might this medicine suit my symptoms and health?
- Which early side effects are common, and which need urgent advice?
- Could it interact with anything else I take?
- When will we review whether it is helping?
- What is the plan if it does not help or I cannot tolerate it?
Starting, changing and stopping safely
Take the medicine as prescribed and do not share it. Seek prompt help if your mood, agitation, behaviour or safety worsens after starting or changing a dose. Do not stop suddenly: withdrawal risk differs between medicines and people, and the dose should usually be reduced gradually with an agreed plan.
Use NHS 111’s mental-health option for urgent help. Call 999 or go to A&E if there is immediate danger to life.
Evidence and official guidance
First published October 2026. Last reviewed: 30 October 2026. Planned review: 30 April 2027.
Prepared for the Pathfields Healthy Living Portal using current NICE and NHS medicines guidance.