SSRI Antidepressants

Serotonin specific or selective serotonin reuptake inhibitors (SSRIs) are antidepressant medications used to treat major depression and other mental health conditions such as bipolar disorder, anxiety and obsessive-compulsive disorder. SSRIs are the most popular type of antidepressants but may cause serious or life-threatening side effects including increased suicide risk, birth defects, and serotonin syndrome.

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Quick Summary

SSRI Antidepressants

Selective serotonin reuptake inhibitor or SSRIs are antidepressant used to treat major depression. They are also used for other mental health conditions such as bipolar disorder, obsessive-compulsive disorder, anxiety disorders, eating disorders, smoking cessation and chronic pain.

SSRIs work by increasing neurotransmitter activity in the brain, specifically serotonin. They were designed to have fewer side effects, but may increase the risk of suicide in children and young adults and have been linked to a high risk of severe birth defects.

SSRI Side Effects

SSRI antidepressants may cause side effects which are mild to moderate and will go away tiwht time such as nausea, sexual dysfunction, insomnia, dizziness, sweating, dry mouth, weight changes, and constipation.

More severe side effects may be serious or life-threatening and include:

  • Suicide – increased risk of suicide may occur when starting medication or changing doses, particularly in children, adolescents and young adults
  • Birth Defects – increased risk of birth defects may include miscarriage, heart defects, persistent pulmonary hypertension of the neonatal (PPHN), and brain, skeletal or abdominal abnormalities such as anencephaly, craniosynostosis or omphalocele.
  • Withdrawal – Long-term use of SSRIs may lead to physical dependence in some patients. If the medication is suddenly stopped, it may cause withdrawal symptoms known as “SSRI discontinuation syndrome”.
  • Serotonin Syndrome an excess of serotonin in certain areas of the brain may cause symptoms including changes in mental function, blood pressure, heart rate, muscle symptoms, fever or severe nausea, vomiting and diarrhea, and in some cases may be fatal

Severe or sudden side effects should be reported to a medical professional and may require emergency treatment.


Antidepressants are prescription drugs used to treat depression. They are also used for several other conditions including bipolar disorder, anxiety disorders, eating disorders, obsessive compulsive disorder, and chronic pain.

Selective serotonin reuptake inhibitors, or SSRIs, are the most common type of antidepressant un use in the U.S. and around the world. The first SSRI medication to be released in the U.S. market was Prozac in 1988 and since then, antidepressants have gained massive popularity and have become the most commonly prescribed medications in the U.S. population. Today’s market features more than a dozen SSRIs.

What Is an SSRI?

SSRI antidepressants work to increase levels of serotonin in certain areas of the brain. Serotonin is a naturally occurring chemical which is produced in the body and brain. It is a chemical messenger, or neurotransmitter associated with regulating mood, learning, and sleep. Selective serotonin reuptake inhibitor or SSRI medications block, or inhibit, the brain from reabsorbing serotonin after it is produced. This increases serotonin levels to higher than normal.

The term “selective” in the name of this class of drugs refers to the fact that the main neurotransmitter they affect is serotonin. Older antidepressants were not “selective” and may have worked on a wider variety of neurotransmitter types.

Among the most popular antidepressants are Prozac, Zoloft, Paxil, Lexapro, Celexa and Effexor.

SSRI Antidepressant Side Effects

Side effects are extremely common in patients who take antidepressants. These side effects range from minor to severe and life-threatening but most common side effects are mild to moderate and will go away with time.

Common side effects from antidepressants may include:

  • Nausea
  • Fatigue
  • Rash
  • Diarrhea
  • Headaches
  • Irritability
  • Dry mouth
  • Increased sweating
  • Drowsiness
  • Insomnia
  • Weight gain or loss
  • Decreased sexual desire
  • Sexual dysfunction

SSRI Severe Antidepressant Side Effects

Because SSRIs are “selective” to serotonin, they have been considered safer and have fewer side effects than older medications. Despite their improved safety profile, SSRIs may still cause severe side effects, some of which may be serious or life-threatening.

SSRI Birth Defects

Pregnant women taking SSRI antidepressants may be at increased risk of birth defects in their developing fetus.

The FDA uses pregnancy categories to warn doctors and patients of pregnancy risks associated with medication use. Prescription medications are categorized by the U.S. Food and Drug Administration (FDA) as A through D and pregnancy category X.

  • Category A medications have been tested in animals and pregnant women and have shown no adverse effects.
  • Category B medications have not shown any risk in animal studies but there are no adequate studies done in pregnant women.
  • Category C medications have shown birth defect risk in animals and there are no adequate studies in humans, but the potential benefits of the medication may outweigh potential risks.
  • Category D medications have shown fetal injury in both animals and humans, but the potential benefits may still outweigh a significant risk.
  • Category X medications are known to be highly teratogenic or will cause fetal harm to both animals and humans as shown in drug studies or adverse event reports. These risks clearly outweigh any potential benefits and should not be used in pregnant women.

Though most SSRIs were initially considered to be Category B pregnancy medications, most of the drugs were upgraded and are now considered to be Category C and should only be taken if benefits clearly outweigh the risks.

Birth defects associated with SSRI medications have included:

  • Persistent Pulmonary Hypertension in Newborn (PPHN)
  • Hypoplastic Left/Right Heart Syndrome (HLHS, HRHS),
  • Anencephaly (born without part of brain, skull and scalp)
  • Spina Bifida (underdeveloped vertebra which leaves spinal cord exposed)
  • Cleft Palate or Lip (missing portion of roof of mouth or upper front jaw)
  • Omphalocele (abdominal organs on outside of body)
  • Scoliosis (curved spine)
  • Club feet (feet curl inwards)
  • Autism Spectrum Disorder (ASD) or Delayed Development Disorder (DDD)
  • Withdrawal symptoms or Serotonin Syndrome in infants

In some cases, birth defects require surgery to correct skeletal deformities but in other cases, malformations may be fatal.

SSRI Suicide

In 2004, the U.S. food and Drug Administration (FDA) issued a “black box warning” regarding SSRI antidepressants and suicide risk. A black box warning is required to be printed at the top of all prescribing information, enclosed in a thick, black border, and is the most severe safety warning that is issued by the FDA.

SSRI medications have been shown to increase the risk of suicide in patients who are depressed. Patients who are under the age of 25, have bipolar disorder, or who have a history of suicidal behaviors or thoughts may be at increased risk.

The increased risk may be worse when a medication is first started or during dosing changes. Health care providers should closely monitor patients who could be at risk.

SSRI Withdrawal

While SSRIs are not considered chemically addictive, many patients suffer withdrawal because they become dependent on them during treatment. During dependency, the patient comes to need the drug to maintain normal mental and physical functioning.

In some cases, patients can develop a condition referred to as SSRI Discontinuation Syndrome and may experience symptoms including:

  • Dizziness
  • Nausea/Diarrhea
  • Diarrhea
  • Headache
  • Chills and shivers
  • Brain “zaps”
  • Electrical type skin sensations

In some cases, tapering off of medication over a period of time rather than simply or suddenly stopping medication may decrease withdrawal effects, however some patients will continue to experience symptoms.

SSRI Serotonin Syndrome

SSRI medications may cause “serotonin syndrome” due to an excess of serotonin concentration in the brain. Serotonin syndrome may be more likely if SSRIs are taken with other medications that also affect serotonin such as treatments for migraine, cough suppressants, and certain herbal remedies.

Serotonin syndrome may include symptoms such as:

  • Excessively high fever
  • Increased heart rate and heart rhythm changes
  • Loss of balance or coordination
  • Confusion and hallucinations
  • Seizures

In some cases, serotonin syndrome may be life-threatening. All medications should be discussed with a physician to avoid drug interactions and sudden or severe symptoms should be reported to a health care practitioner right away.

SSRI Antidepressant Lawsuits

Antidepressant manufacturers have been accused of failing to warn the public about the harmful effects of their medications. Thousands of SSRI lawsuits have been filed against major manufacturers including Forest Laboratories, Eli Lilly, Pfizer and other drug companies by people or loved ones of those who were harmed by the medications.

Notwithstanding claims relating to this product, the drug/medical device remains approved by the U.S. FDA.