Antidepressants Explained: Types, Side Effects, and What to Expect

Antidepressants are medications widely used to treat depression and other mental health conditions. If you’ve been prescribed an antidepressant – or are simply curious about them – it’s helpful to understand the basics. Knowing the different types, possible side effects, and what to expect when starting treatment can make the process feel far less intimidating. In this guide, we break down the main classes of antidepressants, explain common side effects and why they happen, and outline what the early weeks of treatment typically look like.

Types of Antidepressants

Antidepressants aren’t all the same. There are several different classes, each working on brain chemistry in its own way:

• SSRIs (Selective Serotonin Reuptake Inhibitors): Often prescribed first because they are effective and generally well tolerated.
• SNRIs (Serotonin–Norepinephrine Reuptake Inhibitors): Similar to SSRIs, but they also affect norepinephrine and may help with certain pain conditions.
• Atypical antidepressants: A varied group that can be useful when SSRIs or SNRIs aren’t the right fit.
• Tricyclic antidepressants (TCAs): Older medications that are effective but often come with more side effects.
• MAOIs (Monoamine Oxidase Inhibitors): Powerful medications that are used less often due to dietary restrictions and interaction risks.
• Newer or niche options: Specialised treatments sometimes used in treatment-resistant or specific clinical situations under close supervision.

The key takeaway is that if one antidepressant doesn’t work well for you or causes troublesome side effects, there are many alternatives to explore.

Common Side Effects and How to Handle Them

Side effects vary depending on the medication and the individual. Many are temporary and improve within the first couple of weeks:

• Nausea or upset stomach: Often settles within 1–2 weeks; taking medication with food may help.
• Headache: Common early on and usually short-lived.
• Insomnia or drowsiness: Adjusting the timing of your dose (morning vs evening) can sometimes help.
• Dry mouth: Drinking water, using sugar-free gum, and good oral hygiene are helpful.
• Dizziness or light-headedness: Standing up slowly can reduce symptoms; persistent dizziness should be reported.
• Sexual side effects: Relatively common with SSRIs and SNRIs; your doctor can discuss management options.
• Weight changes: Some antidepressants increase appetite, while others are weight-neutral.
• Early mood or energy changes: Some people feel temporarily more anxious or restless when starting treatment.

Important safety note: In people under 25, antidepressants can slightly increase suicidal thoughts during the early weeks of treatment, which is why close monitoring is essential. At any age, if thoughts of self-harm occur, urgent medical help should be sought immediately.

What to Expect When Starting an Antidepressant

• Weeks 1–2: Side effects may appear before benefits; mood improvement is usually not immediate.
• Weeks 3–4: Some people notice early improvements in sleep, appetite, or energy.
• Weeks 6–8: Clearer mood improvement is often felt if the medication is a good match.
• Beyond 8 weeks: If there’s little improvement, your doctor may adjust the dose or suggest a different medication.

For a first episode of depression, antidepressants are often continued for 6–12 months after symptoms improve, although this varies from person to person. Never stop antidepressants suddenly, as withdrawal symptoms can occur. If stopping is appropriate, your doctor will guide a gradual taper.

When to Talk to Your Doctor

You should contact your healthcare provider if side effects are severe or not improving, if your mood worsens or suicidal thoughts occur, if there’s no improvement after an adequate trial, or if you’re considering changing or stopping your medication.

Conclusion: Looking Forward

Starting an antidepressant can feel daunting, but understanding what to expect can make the journey easier. Give the medication time to work, stay in regular communication with your healthcare provider, and don’t struggle in silence with side effects. With the right medication and good support, antidepressants can be a valuable part of recovery and help you get back to feeling like yourself.

Sources:

• Cleveland Clinic – Antidepressants: Uses, Side Effects & Types (Medically reviewed Aug 29, 2025)
• National Institute of Mental Health (NIMH) – Mental Health Medications (Antidepressants section)
• Healthline – A Guide to Common Antidepressant Side Effects (Dec 2018)
• Mayo Clinic – Selective Serotonin Reuptake Inhibitors (SSRIs)
• FDA – Antidepressant Patient Medication Guide