9 Side Effects Of Antidepressants You Must Watch Out For

Side effects of anti-depression pills.

Major depressive disorder or clinical depression is a common mental disorder, with over 19 million Americans diagnosed every year.1 If you or anyone dear to you is struggling with depression, seeking and starting treatment is a major step in taking charge. However, it’s also important to educate yourself about possible side effects of depression medication so you know what concerns you’ll need to raise with your psychiatrist.

Depression is usually treated with a combination of psychotherapy and medication which regulate the activity of certain neurotransmitters or chemical “messengers” such as serotonin in the brain. Side effects of antidepressants usually depend on the class of medicines prescribed. Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressants today.2 Fluoxetine, which has risen to cult status for its supposed mood-lifting properties, citalopram, and paroxetine belong to this category of drugs. Other depression medicines include serotonin-norepinephrine reuptake inhibitors (SNRIs) and norepinephrine-dopamine reuptake inhibitors (NDRIs). The new antidepressants are generally considered to be more effective and much safer than tricyclics or tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs), the older line of treatment for depression.3 However, these newer lot of antidepressants are not without some side effects. In some extreme cases, they can also be debilitating.


If you have been prescribed antidepressants, you should monitor your condition regularly and promptly report any symptoms to the psychiatrist. Here are some of the most common side effects of antidepressants to watch out for.

1. Nausea, Indigestion, And Stomach Upsets

Some side effects of antidepressants may be temporary and will settle once your body gets used to the medication. Depending on the severity of side effects, your doctor may even switch some medication. The important thing is to continue treatment, communicate with your doctor, and not stop taking any prescribed medication on your own.


Usually, the earliest side effects of antidepressants are nausea, diarrhea, and vomiting. Up to 40% of patients using certain SSRIs report these symptoms.4 SSRIs and SNRIs can also cause digestive issues, including stomach pain and diarrhea or constipation. A loss of appetite is also common. Older drugs like TCAs have also been associated with constipation. But, fortunately, these effects are mild and temporary and tend to get better after a few days.

2. Weight Gain

Weight gain is considered one major factor in noncompliance in treatment with antidepression, with patients stopping medication on their own when they see this effect.5 Rather than discontinuing your meds prematurely, talk to your physician about your options to get on top of this.


Some antidepressants can cause a weight gain of 10 pounds or more, especially after about 6 months of use. Tricyclics are more likely to increase appetite and cause you to pile on the extra pounds than other drugs. In fact, weight gain was one of the main reasons cited for switching to newer drugs in the late nineties.6 However, even the new crop of antidepressants may have this effect. SSRIs could start by causing weight loss but their long-term use may eventually lead to weight gain.

Why does this happen? There are no clear answers yet. That said, connections to metabolism, huger levels, and overeating are being explored. Depression itself is known to cause weight-related fluctuations, where some lose their appetites while others eat a lot as levels of serotonin, the hormone which also determines appetite, take a hit. Your doctor may advise dietary changes and exercises to combat this weight gain. A change in medications may also be suggested after weighing in the pros and cons and depending on how you are responding to the medication overall.


3. Sexual Dysfunction

Sexual dysfunction is another commonly reported problems associated with the use of depression medication and often affects the patient’s recovery and quality of life. SSRIs increase the serotonin levels in the body and this slows down the response of the brain to sexual stimuli. The result is reduced sexual desire, difficulty in getting and maintaining an erection in men, vaginal dryness in women, and delayed orgasm in both sexes.7 When this happens, doctors sometimes alter the dosage, prescribe meds to be taken in tandem, or even replace the existing prescription.8

4. Dry Mouth And Blurred Vision

Although very uncommon, involuntary movements like twitching, muscle spasms, and tics and trembling can be a side effect of antidepressants, especially in the elderly.9 Joint pain, muscle pain, and headaches, as well as dizziness, are also common side effects when you start antidepressants.


These symptoms are most commonly associated with TCAs which work by blocking receptors to certain neurotransmitters in the brain. This reduces the production of tears, leading to blurred vision. It can also result in dehydration and related symptoms such as dryness in the mouth and constipation. These symptoms usually subside within a few weeks of treatment.10

5. Sleep Disturbances

Most antidepressants work by regulating various neurotransmitters, including dopamine and serotonin which have a prominent role in the sleep–wakefulness cycle. These drugs also suppress or terminate the REM sleep cycle. Because of the complex role of neurotransmitters in the sleep cycle, the side effects of medicines that alter these chemicals are often intense and vary from patient to patient. For example, while some patients who take the drug fluoxetine suffer from insomnia, others report lethargy or daytime sleepiness. Frequent nightmares and sleepwalking have also been reported with SSRIs, again wreaking havoc on sleep. If sleep-related side effects of antidepressants are severe and do not reduce after a few weeks, your doctor may prescribe a medication from another family of antidepressants or a different drug from the same family.11


6. Suicidal Tendencies

An FDA advisory warns that children, adolescents, and young adults taking antidepressants must especially be watched carefully for suicidal thoughts and behaviors. Withdrawal from social interactions, agitation, and listlessness are all red flags.

Suicidal tendencies or self-harm behavior is another grave side effect that has been seen in some cases of antidepressant use, especially in the first few weeks of treatment. There’s some irony in this. When a person’s depressive symptoms reduce as a result of medication, they may start to “feel” the implications of their situation more strongly. So while earlier they were too listless to act on their helplessness or hopelessness, now they may want a way out. And this often results in suicidal thoughts. Young people aged under 25 years who may be taking antidepressants for the first time are especially vulnerable.


Aggressiveness, violence, hostility, and extreme mood swings are some dangerous side effects of antidepressants that need to be watched out for. These need immediate medical intervention.

This is why regular follow-up, monitoring, and prompt communication with your physician are all important when you are on antidepressants. If you are starting an antidepressant, you should also keep family or close friends informed. Ask them to watch out for any red flags or changes in behavior and reach out for help if need be.12 13 Children and adolescents in particular need to be watched closely.

7. Serotonin Syndrome

Prolonged use of some antidepressants may contribute to cardiac arrhythmia and the risk of type 2 diabetes. While the exact connection to diabetes is not clear, it may be linked to weight gain.14 While these findings are still tenuous, long-term users of depression medication should get regular physical check-ups.

This is a rare but serious side effect linked to SSRIs and SNRIs caused by excess levels of serotonin in your brain. This usually happens when you take these antidepressants with other medication increases serotonin levels, say other antidepressants or medicines with lithium used to treat bipolar disorder, or even triptan medications used to treat migraine headaches. Taking antidepressants with natural remedies like St John’s Wort could also be a trigger, which is one reason you must keep your doctor posted about any alternative medicines you take. Serotonin syndrome can cause symptoms like:

  • Confusion and agitation
  • Hallucinations
  • Shivering, sweating, and muscle twitching
  • Fever
  • Blood pressure fluctuation
  • Diarrhea

If you see these symptoms together or in tandem, see your doctor immediately. Severe serotonin syndrome could even cause fits, arrhythmia, and loss of consciousness and is a medical emergency.1516

8. Hyponatremia

Antidepressants are also associated with premature delivery and low birth weight during pregnancy. Side effects such as irritability, jitters, shivering, and withdrawal symptoms may also be seen in the newborn baby. With depressed women who are planning a pregnancy or are pregnant, doctors often weigh in all pros and cons before prescribing medication. There is also the larger possibility of the depression itself affecting the baby so this is considered too.17

This side effect is usually seen in elderly patients, especially with SSRIs. These meds may interfere with the hormone that controls the level of fluid and sodium in the body. The effect is much more severe in elderly people because the body’s ability to regulate fluid levels reduces with age. The result is a severe fall in sodium levels that can lead to fluid accumulation in cells. Look for signs like nausea and vomiting, headaches, confusion, and fatigue. In extreme cases, it can even lead to a coma or seizures.18

9. Relapse Or Tachyphylaxis

“Discontinuation syndrome” refers to the series of symptoms that you may experience when you stop taking antidepressants, especially abruptly. This may include side effects like fatigue, dizziness or loss of coordination, blurred vision, and insomnia. Diarrhea or nausea, anxiety, mood swings, flu-like symptoms may also be seen.19

Antidepressant tachyphylaxis or “Prozac poop-out” in popular parlance is a condition in which the effect of antidepressants reduces or stops after a few years of treatment. It is considered a form of relapse due to evolving drug tolerance. This loss of response to antidepressants can be aggravated by various factors:

  • Not following medication schedule and dosage: Sometimes the patient starts feeling better after taking antidepressants for a while and decides to discontinue medication, or starts skipping doses.This is the most common cause of tachyphylaxis.
  • Placebo effect: Some of the relief attributed to antidepressants may actually be the result of the patient’s expectations. This placebo response is likely to wane within a few months of starting treatment.20
  • Other undiagnosed conditions: Patients with undiagnosed bipolarity are more likely to suffer from tachyphylaxis than those with unipolar depression.21

Antidepressants And Drug Interactions

If you have been prescribed an antidepressant and you already take medications for other conditions, make sure you mention it to your psychiatrist. Some drugs may combine to aggravate or create undesirable side effects. For instance, the interaction of SSRIs with medicines containing alcohol can result in increased and prolonged sedation. Similarly, when combined with aspirin, these drugs may increase the risk of gastrointestinal bleeding.

It may seem disconcerting that something that should bring you relief from depression could have such grave risks and fallouts. But what needs to be stressed is that some of these are temporary while others can be managed with a change of medication. Alternative options like cognitive behavior therapy may also work out for you. The important thing is to be aware and prompt in responding to these.