Few topics in mental health cause as much debate as antidepressants. Some people say they gave them their life back. Others felt numb, gained weight or had a hard time stopping. Both experiences are real, and both are part of what research shows.
This article explains what antidepressants are, what is known about how they work, how well they help, which side effects are common, and what to know about stopping. It is meant to help you understand and ask good questions. Decisions about starting, changing or stopping medication should always be made together with a doctor.
What antidepressants are
Antidepressants are medications used mainly for depression, and also for anxiety disorders, obsessive-compulsive disorder, some pain conditions and other problems. The most commonly prescribed groups are:
- SSRIs (selective serotonin reuptake inhibitors), such as sertraline, citalopram, escitalopram or fluoxetine
- SNRIs (serotonin and noradrenaline reuptake inhibitors), such as venlafaxine or duloxetine
- Other newer antidepressants, such as mirtazapine, bupropion, agomelatine or vortioxetine
- Older tricyclic antidepressants, such as amitriptyline, which are used less often today for depression
In Germany, antidepressants can be prescribed by general practitioners and psychiatrists. Psychologists and psychotherapists cannot prescribe medication. More on the different professions in Psychologist, psychiatrist, psychotherapist or Heilpraktiker.
How do they work?
For a long time, depression was explained as a “chemical imbalance”, a lack of serotonin that antidepressants correct. This idea is no longer supported in its simple form. A large umbrella review found no consistent evidence that depression is caused by low serotonin levels or activity (Moncrieff et al., 2023). That does not mean antidepressants cannot help. It means that how they help is more complicated than the old explanation suggested.
One newer explanation focuses on emotional processing. Researchers have found that antidepressants can shift how people perceive emotional information quite early, for example making them slightly more likely to notice positive facial expressions, even before mood improves. Over weeks, in interaction with daily life and relationships, these small shifts may help mood to recover (Harmer et al., 2017). Other theories focus on changes in stress systems and in the brain’s ability to adapt.
How well do they work?
A large network meta-analysis compared 21 antidepressants in more than 116,000 people with depression. All of them worked better than placebo in the short term, though the differences between drugs in effectiveness and in how well people tolerated them were moderate (Cipriani et al., 2018).
On average, the extra benefit over placebo is modest. An analysis of data from 232 trials submitted to the US Food and Drug Administration suggests a more nuanced picture: rather than everyone improving a little, about 15% of participants seemed to have a substantial response to the medication beyond the placebo effect (Stone et al., 2022). For some people antidepressants make a large difference, for others a small one or none, and research cannot yet predict well who belongs to which group.
Antidepressants usually take two to six weeks before the effect on mood becomes noticeable, while some side effects can appear earlier. This is one reason why regular contact with the prescribing doctor in the first weeks matters.
Side effects
Side effects differ a lot between medications and between people. A large analysis of side-effect profiles found big differences between antidepressants in effects on weight, heart rate, blood pressure and other measures, and argued that choosing a medication should take a person’s own priorities and health risks into account (Pillinger et al., 2023).
Common side effects include:
- nausea, stomach problems or changes in appetite
- sleep problems or tiredness
- weight gain with some medications
- sexual side effects, such as lower desire or difficulty reaching orgasm
- feeling emotionally flat or blunted
- restlessness or, in the first weeks, increased anxiety
Many side effects ease after the first weeks. Others persist and are a common reason for people to stop. It is important to talk about them openly with your doctor, including sexual side effects, which people often feel embarrassed to mention. Sometimes a lower dose or a different medication helps.
In young people especially, and in anyone, the first weeks of treatment or a change in dose can occasionally bring more agitation or dark thoughts. If this happens, contact your doctor straight away.
Stopping antidepressants
Stopping suddenly can lead to withdrawal symptoms, such as dizziness, “electric shock” sensations, irritability, sleep problems, flu-like feelings or low mood. A review of the available evidence found that the risk and severity of withdrawal seem to increase with longer use, and that SNRIs and paroxetine are associated with higher risks than other antidepressants, although the data are still limited (Horowitz et al., 2023). For this reason, doctors usually recommend reducing the dose gradually, sometimes very slowly.
Stopping also carries the risk of relapse. In a meta-analysis of 40 studies, people who continued their antidepressant after recovering from depression relapsed less often than people who were switched to placebo (Kato et al., 2021). This does not mean everyone has to take medication forever. It means that the decision to stop is worth planning with your doctor, at a stable time in your life, and ideally with support such as psychotherapy.
Questions to ask your doctor
What is this medication for in my case? Which side effects are common, and which ones should I report immediately? How long until I might notice an effect? How long should I take it? What would happen if I wanted to stop, and how would we do that safely?
Medication and psychotherapy
Antidepressants and psychotherapy are not opposites. For many people with moderate or severe depression, a combination works best, and many people move from one to the other over time. If you are wondering whether medication makes sense for you, Do I need medication? looks at this question in more detail, and Depression: what it is, how it feels and what helps describes other forms of support.
If you are in crisis or having thoughts of ending your life, please call your local emergency number (for example 112 in Europe or 911 in North America and Mexico), or find a free, confidential helpline in your country at findahelpline.com.
More about therapy with me.
References
- Cipriani, A., Furukawa, T. A., Salanti, G., Chaimani, A., Atkinson, L. Z., Ogawa, Y., Leucht, S., Ruhe, H. G., Turner, E. H., Higgins, J. P. T., Egger, M., Takeshima, N., Hayasaka, Y., Imai, H., Shinohara, K., Tajika, A., Ioannidis, J. P. A., & Geddes, J. R. (2018). Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder: a systematic review and network meta-analysis. Lancet, 391(10128), 1357–1366. https://doi.org/10.1016/s0140-6736(17)32802-7
- Harmer, C. J., Duman, R. S., & Cowen, P. J. (2017). How do antidepressants work? New perspectives for refining future treatment approaches. The Lancet. Psychiatry, 4(5), 409–418. https://doi.org/10.1016/s2215-0366(17)30015-9
- Horowitz, M. A., Framer, A., Hengartner, M. P., Sørensen, A., & Taylor, D. (2023). Estimating risk of antidepressant withdrawal from a review of published data. CNS Drugs, 37(2), 143–157. https://doi.org/10.1007/s40263-022-00960-y
- Kato, M., Hori, H., Inoue, T., Iga, J., Iwata, M., Inagaki, T., Shinohara, K., Imai, H., Murata, A., Mishima, K., & Tajika, A. (2021). Discontinuation of antidepressants after remission with antidepressant medication in major depressive disorder: a systematic review and meta-analysis. Molecular Psychiatry, 26(1), 118–133. https://doi.org/10.1038/s41380-020-0843-0
- Moncrieff, J., Cooper, R. E., Stockmann, T., Amendola, S., Hengartner, M. P., & Horowitz, M. A. (2023). The serotonin theory of depression: a systematic umbrella review of the evidence. Molecular Psychiatry, 28(8), 3243–3256. https://doi.org/10.1038/s41380-022-01661-0
- Pillinger, T., Howes, O. D., Correll, C. U., Leucht, S., Huhn, M., Schneider-Thoma, J., Gaughran, F., Jauhar, S., McGuire, P. K., Taylor, D. M., Young, A. H., & McCutcheon, R. A. (2023). Antidepressant and antipsychotic side-effects and personalised prescribing: a systematic review and digital tool development. The Lancet. Psychiatry, 10(11), 860–876. https://doi.org/10.1016/s2215-0366(23)00262-6
- Stone, M. B., Yaseen, Z. S., Miller, B. J., Richardville, K., Kalaria, S. N., & Kirsch, I. (2022). Response to acute monotherapy for major depressive disorder in randomized, placebo controlled trials submitted to the US Food and Drug Administration: individual participant data analysis. BMJ, 378, e067606. https://doi.org/10.1136/bmj-2021-067606
This article is exploratory and meant for information and reflection. It cannot capture the full complexity of any individual situation, and your own experience may be different. It does not replace a diagnosis or treatment.
