Antidepressants: types, how they work and what to expect
Find out about the different types of antidepressants available and how they work as part of a wider treatment plan.
Antidepressants are one of the most commonly prescribed treatments for depression and other mental health conditions. They can play an important role in helping people feel better and take steps towards recovery.
While antidepressants aren’t a one-size-fits-all solution, many people do find them helpful. Like any treatment, they work best when they’re tailored to your individual needs. They’re often used alongside talking therapies, self-care and complementary treatments.
If you're considering antidepressants or have just started taking them, it's natural to have questions or concerns. You might wonder how they work, whether they’ll actually help or what side effects to expect. Some people worry about becoming reliant on medication or whether it will make them feel worse.
This page will guide you through:
- What antidepressants are and when they’re prescribed
- How antidepressants work and how long it takes to see an effect
- What types of antidepressants are available
- What to expect in terms of benefits and side effects
- What to do if you're thinking about stopping or switching your medication
- How antidepressants fit within a wider treatment plan
What are antidepressants?
Antidepressants are prescription medications used to treat depression as well as other mental health conditions, including:
- Anxiety disorders (for example, generalised anxiety disorder (GAD) or panic disorder)
- Obsessive compulsive disorder (OCD)
- Post-traumatic stress disorder (PTSD)
- Eating disorders
- Chronic pain conditions
Antidepressants usually work best as part of a wider treatment plan. This might include talking therapies or counselling, as well as alternative treatments like neuromodulation or repetitive transcranial magnetic stimulation (rTMS). Some people may also benefit from support with nutrition, residential care in a hospital or inpatient setting, and lifestyle changes such as relaxation techniques, regular exercise and better sleep.
For many people, a combination of treatment types can prove effective in managing depression.
How antidepressants work
Antidepressants work by affecting neurotransmitters. These are the natural chemicals in the brain that help regulate your mood, sleep, energy levels and stress responses. When these chemicals are out of balance, it can contribute to conditions like depression and anxiety.
Most antidepressants help by increasing the availability of two neurotransmitters in particular - serotonin and norepinephrine. These help brain cells communicate more effectively and play a key role in emotional regulation.
By adjusting the levels of key neurotransmitters, antidepressants can relieve symptoms, which can help people respond better to therapy and other treatments.
One of the most commonly prescribed types of antidepressants are selective serotonin reuptake inhibitors (SSRIs). They work by blocking the reabsorption (or reuptake) of serotonin in the brain so more of it remains available to support mood and emotional stability.
Antidepressants aren’t designed to numb your emotions. Their aim is to reduce the intensity of symptoms like deep sadness, anxiety or hopelessness. Daily life can then become more manageable, allowing recovery to begin.
How long do antidepressants take to work?
If you've just started taking antidepressants, it's natural to hope for quick relief. While the effects aren’t usually immediate, many people start to notice changes after a few weeks. In general, it can take 2 to 4 weeks to see an improvement in symptoms and up to 6 weeks or more to feel the full benefits. During this time, you might notice positive changes like feeling more motivated, sleeping better and finding it easier to manage day-to-day stress.
In the first few days of treatment, it's common to experience mild side effects. These might include:
- Nausea
- Headaches
- Sleep changes
- Upset stomach
- Feeling a bit more anxious or restless
- On rare occasions, suicidal thoughts
These early side effects are often a normal part of starting antidepressants. Try not to feel discouraged; they’re usually short-term and tend to ease after a week or two as your body adjusts.
Don’t stop taking your medication suddenly if you experience side effects. If you’re concerned, always talk to your doctor. They can help with coping strategies and advise on any next steps.
Finding the right treatment can take time. The first option may not be the right fit for you. If you haven’t noticed any improvement in your symptoms after 4 to 6 weeks, speak to your doctor. They may suggest giving it more time, trying a different dose or type of medication, or combining medication with talking therapy.
Examples of antidepressants you might be prescribed
There are several types (or classes) of antidepressants, each working in slightly different ways. The one your doctor recommends will depend on your symptoms, personal history and any other health conditions you may have.
S elective serotonin reuptake inhibitors (SSRIs)
- How they work: Increase levels of serotonin by blocking its reabsorption (reuptake) in the brain
- When used: Often the first-line treatment for depression and anxiety disorders
- Common medications: Sertraline, Citalopram, Fluoxetine
- Side effects: Nausea, headache, sleep changes, mild anxiety at first – often easing within 1 to 2 weeks
Serotonin and norepinephrine reuptake inhibitors (SNRIs)
- How they work: Boost levels of both serotonin and norepinephrine
- When used: For moderate to severe depression, especially if SSRIs haven’t helped
- Common medications: Venlafaxine, Duloxetine
- Side effects: Similar to SSRIs but may also include dizziness or dry mouth
Tricyclic antidepressants (TCAs)
- How they work: Increase serotonin and norepinephrine by affecting their reabsorption
- When used: Less commonly prescribed due to side effects, but can be helpful for chronic pain – or if other treatments haven’t worked
- Common medications: Amitriptyline, Nortriptyline
- Side effects: Drowsiness, dry mouth, constipation. These usually start early and can fade over time
Monoamine oxidase inhibitors (MAOIs)
- How they work: By blocking an enzyme (monoamine oxidase) that breaks down neurotransmitters like serotonin
- When used: Rarely – typically only for cases that haven’t responded to other treatments
- Common medications: Phenelzine, Tranylcypromine
- Side effects: Can include serious interactions with certain foods and medications. Close monitoring is required
Atypical antidepressants
- How they work: Varies – some affect dopamine, others modulate serotonin differently
- When used: When SSRIs or SNRIs aren’t suitable, or cause unwanted side effects
- Common medications: Mirtazapine (can help with sleep and appetite), Bupropion (may also be used for stopping smoking)
- Side effects: Can include drowsiness or weight changes (Mirtazapine) or insomnia and dry mouth (Bupropion)
When are antidepressants prescribed?
Antidepressants are usually prescribed for moderate to severe depression. They can be particularly helpful when symptoms persist over time, interfere with daily life or haven’t improved with self-care or therapy alone.
They may also be used for anxiety disorders, PTSD, OCD or when someone is at risk of harm due to their symptoms.
Doctors don’t prescribe antidepressants lightly. They carefully consider your personal situation, medical history and preferences before recommending them. In many cases, medication is prescribed alongside talking therapy, not instead of it.
Choosing the right antidepressant
Doctors will take several factors into account when choosing an antidepressant, including:
- Your main symptoms (such as low mood, anxiety and insomnia)
- Any other conditions you have (mental or physical)
- Your past experience with medications
- Potential side effects and how they may affect you
It may take a few attempts to find the best fit. Your GP or psychiatrist will work with you to adjust your medication until it feels right.
Coming off antidepressants
If you’re thinking about coming off your antidepressants because you feel better, or you’re experiencing side effects and want to stop, it's important to do so safely and gradually. Stopping suddenly can lead to uncomfortable withdrawal symptoms or cause your original symptoms to return.
Even if you're feeling well, coming off antidepressants too quickly can lead to physical and emotional side effects, sometimes called discontinuation symptoms.
These might include:
- Dizziness or ‘brain zaps’
- Nausea or flu-like symptoms
- Anxiety or low mood
- Sleep problems or vivid dreams
Not everyone experiences these symptoms. When they do occur, they’re usually mild and temporary, especially if the medication is reduced gradually under medical guidance (known as tapering).H3: The tapering process
Tapering means slowly reducing your dose over time, allowing your body to adjust. Your doctor or psychiatrist will suggest a tapering plan based on the type of antidepressant you’re on, how long you’ve been taking it, the dose you’re currently taking and how you’ve responded to medication in the past.
Tapering could span a few weeks or may take longer if the dose is adjusted in small steps.
Remember, always speak to your doctor before changing or stopping your medication even if you feel well. They’ll help you reduce it safely and provide support throughout the process.
Antidepressants as part of a broader treatment plan
Antidepressants can play a valuable role in treating depression, especially when symptoms are moderate to severe.
Treating depression is about more than just managing symptoms. It’s also about addressing the underlying causes and helping you to build coping strategies that support long-term mental health. With this in mind, antidepressants are often most effective as part of a wider recovery strategy that looks at your overall wellbeing.
At Priory, we take a whole-person approach by treating your symptoms while also exploring any underlying causes and contributing factors. This type of treatment plan may include:
- Talking therapies, like cognitive behavioural therapy (CBT), to help you explore thoughts, behaviours and triggers
- Lifestyle changes, such as regular exercise, sleep routines and nutrition
- Stress management techniques, like mindfulness, grounding exercises or relaxation practices
- Peer or group support
- Specialist care, including outpatient therapy, or residential treatment programmes for more complex needs
Your treatment plan will be tailored to your personal goals, preferences and circumstances. It can evolve over time as your needs change.
If you’re considering support beyond medication, Priory offers therapy and specialist depression treatment options that can be accessed on an outpatient or residential basis, depending on what’s right for you.
FAQs
Discover some commonly asked questions about antidepressant medication.
Can you drink on antidepressants?
It's recommended that you don't drink alcohol when you’re taking antidepressants. This is because alcohol can interact with your medication, making side effects worse or meaning it's not as effective. Also, alcohol is a depressant, so it can actually make your depression symptoms worse.
How does the weather affect you when you take antidepressants?
Some antidepressants, especially TCAs, may impact on your ability to regulate your body temperature. This means that in a heatwave, antidepressants may make more people prone to heat-related illnesses such as heatstroke and heat exhaustion. They might also be more sensitive to hot conditions, meaning they sweat more and are more prone to fainting and sunburn.
If you’re taking TCAs during hot weather, it’s important that you stay out of direct sunlight, use a high factor sun cream, drink plenty of water and don’t do any strenuous activity.
What shall I do if I think my antidepressant dose is wrong?
If you don’t think your antidepressant dose is working, or if it’s causing side effects, it’s important that you speak to your GP or psychiatrist. They may adjust your dose or switch you to a different type of antidepressant that might be more suited to you. However, it’s important that you don’t stop taking your medication without speaking to a doctor first.
How long do I have to take antidepressants?
The length of time that someone has to take antidepressants varies depending on the person and their symptoms.
In general, doctors recommend taking antidepressants for at least 6 months after your symptoms improve. This helps to prevent you from relapsing. However, some people may need to take them for a longer period of time.
Can I switch my antidepressants?
It’s possible for you to switch antidepressants. If you’re experiencing unpleasant side effects or your symptoms don’t seem to be improving, talk to your doctor about trying a different type of antidepressant. They may gradually decrease your current medication while starting you on a new one.
