Antidepressants: what they do, side effects and stopping safely
Antidepressants are medicines used for moderate to severe depression and for anxiety disorders, OCD and PTSD. The most common are SSRIs such as sertraline, fluoxetine and escitalopram. Most people notice some effect within two to six weeks, and the full benefit can take up to eight; treatment usually continues for at least six months after you feel better. Side effects such as nausea or restlessness often settle in the first weeks. They are not addictive in the way alcohol or sleeping pills are, but stopping suddenly can cause withdrawal symptoms, so always reduce the dose gradually with your doctor.
Health writers · Aslam Clinic
Antidepressants are medicines that reduce the symptoms of moderate and severe depression, and several anxiety-related conditions. The most widely used are such as sertraline, fluoxetine and escitalopram. They usually take two to six weeks to start helping, need to be continued for months after you feel better, and must never be stopped suddenly. They are not addictive in the sense of craving or getting “high”, but your body adapts to them, so coming off needs a plan.
In Pakistan, “depression ki goliyan” carry a lot of fear — that they will change your personality, that you will need them forever, or that they are the same as sleeping pills. Most of those fears are not true, and some are partly true. This page separates the two. It gives no doses: those are for your doctor to decide.
What antidepressants are used for
The Royal College of Psychiatrists advises that antidepressants should not usually be the first treatment for mild depression, where talking therapy, exercise and guided self-help are preferred. They are recommended for adults with moderate to severe depression, alone or together with therapy. They are also used for:
- Generalised anxiety disorder, panic disorder and social anxiety
- Some eating disorders
- Some types of long-term pain, including nerve pain and migraine prevention (usually older tricyclic medicines at lower doses)
The main types
| Type | Common examples | Worth knowing |
|---|---|---|
| SSRIs | Sertraline, fluoxetine, escitalopram, citalopram, paroxetine | Usually the first choice; generally well tolerated; taken once a day |
| SNRIs | Venlafaxine, duloxetine | Often used if an SSRI has not helped; duloxetine is also used for nerve pain |
| Mirtazapine | Mirtazapine | Can cause drowsiness and increased appetite and weight; fewer sexual side effects; often taken at night |
| Tricyclics (TCAs) | Amitriptyline, imipramine, clomipramine | Older; more side effects; dangerous in overdose, so used with care where there is suicide risk |
| MAOIs | Moclobemide, phenelzine | Rarely used; some need dietary restrictions; specialist use |
and SSRIs both act on . According to the NHS, the different types generally work about as well as each other for depression; the choice depends on side effects, other conditions, other medicines and what has worked for you before.
How long they take, and how long to continue
Some people notice better sleep or appetite within one to two weeks. Mood usually lifts more gradually, over two to six weeks, and the full effect can take up to eight. This delay is why many people stop too early, thinking the tablet “isn't working”. Your doctor should review you about two weeks after starting — and after one week if you are aged 18 to 25 or there is particular concern about suicide.
Once you are better, the usual advice for a first or second episode is to continue for at least six months, because stopping earlier makes relapse more likely. People who have had several episodes may be advised to continue for longer, with regular reviews.
Common side effects
Most are mild and fade within a couple of weeks. With SSRIs and SNRIs, the Royal College of Psychiatrists lists:
- Feeling agitated, shaky or anxious in the first weeks — a common reason people stop if nobody warned them
- Nausea, indigestion, diarrhoea or constipation, loss of appetite
- Headache, dizziness, dry mouth, sweating
- Sleeping badly, or feeling sleepy
- Reduced sex drive, difficulty reaching orgasm, or erection problems
Sexual side effects are rarely asked about in a Pakistani consultation, and many people quietly stop their medicine instead. Tell your doctor: changing the dose or medicine often helps. Tricyclics more often cause dry mouth, constipation, drowsiness, weight gain and a fast heartbeat.
If the first antidepressant does not help
Not everyone responds to the first medicine, and that does not mean nothing will work. NICE advises that if depression has not improved at all after about four weeks at an effective dose, the doctor should first check the basics: are the tablets being taken regularly, are side effects causing missed doses, and is something else — a physical illness, alcohol, an ongoing crisis at home — getting in the way?
After that, the options include increasing the dose, switching to a different antidepressant, adding a talking therapy or a group exercise programme, or switching to therapy instead. Each change needs time to work. Keep a simple weekly record of sleep, mood and energy to take to your appointments; it makes these decisions far easier.
The “chemical imbalance” question
For years, depression was explained to patients as a shortage of that antidepressants “top up”. In 2022 a large review in Molecular Psychiatry found no consistent evidence that depression is caused by low serotonin, and it received wide media coverage. The Royal College of Psychiatrists had already described the chemical imbalance idea as an oversimplification.
What the review did not show is that antidepressants do not work. That is a separate question, answered by trials rather than theories: a 2018 analysis of 522 trials involving more than 116,000 people found antidepressants more effective than for adults with depression, although the average difference is modest and larger in more severe depression. How they work is still not fully understood; research points to effects on how the brain responds to stress, on negative thinking biases, and on — the brain's ability to form new connections — rather than a simple top-up.
Are they addictive? Stopping safely
Antidepressants do not cause craving or a high, and people do not need ever-larger doses for the same effect, so they are not addictive in the way alcohol, nicotine or sleeping pills are. But the body does adapt to them. If you stop suddenly, miss doses, or cut down too fast, you can get :
- Dizziness, unsteadiness, “electric shock” sensations in the head
- Irritability, anxiety, low mood, tearfulness, vivid dreams or poor sleep
- Nausea, sweating, flu-like aches, headaches
NICE says these are often mild and pass within one to two weeks, but can sometimes be severe and last several weeks or, occasionally, months. Paroxetine and venlafaxine are more likely to cause them. Most people do stop successfully by tapering: reducing the dose in stages over weeks or months, agreed with the prescriber.
Pregnancy, breastfeeding and Ramadan
Pregnancy and breastfeeding. Some antidepressants have been used in pregnancy for many years, and untreated depression carries its own risks for mother and baby. Many women relapse after stopping medicine in pregnancy. If you are pregnant, planning pregnancy or breastfeeding, do not stop on your own — discuss the balance of risks with your doctor, who can advise on the options with the most safety information.
Ramadan. Most SSRIs are taken once a day, and can usually be moved to sehri or iftar, provided you take them at the same time every day. Those taken twice a day may need a change of timing or preparation. Discuss this with your doctor before Ramadan rather than skipping doses — irregular dosing is itself a cause of withdrawal symptoms.
Getting the most from treatment
- Take it at the same time each day, and set a phone reminder.
- Give it at least four to six weeks at an effective dose before judging it — unless side effects are severe.
- Tell your doctor about every other medicine, including painkillers such as tramadol, migraine tablets, herbal products and anything bought over the counter.
- Avoid alcohol, which worsens depression and can interact with the medicine.
- Combine medicine with therapy, activity and sleep routines where you can; for more severe depression, NICE's first choice is an antidepressant together with CBT.
- Never share tablets with family members, however similar their symptoms seem.
Common questions
Still not sure what to do?
Reading about a symptom only goes so far. A doctor who can ask you questions and examine you will get further in ten minutes than any article can.
