Antidepressant Overdose

What to Do Whether the Abuse Was Accidental or Not

Overdose on Antidepressants?
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Antidepressants can be an effective means of treating depression, anxiety, and other mood disorders when used properly and taken in the prescribed dosages. But the effects can harmful, and even dangerous if taken in excess or used with alcohol or drugs.

Antidepressants may be intentionally misused with the aim of committing suicide. Others will abuse them to enhance their mind-altering effects, ranging from increased sociability and euphoria to "time-bending" hallucinations.

Both of these situations are more commonly seen with older tricyclic antidepressants (TCAs), although newer selective serotonin reuptake inhibitors (SSRIs) can also be misused.

Antidepressants and Suicide

Prescription drugs account for the majority of suicides by overdose with antidepressants being one of the more common types used. Some estimates suggest that as many as a thirds of all prescription drug overdoses involve a TCA.

A study conducted in 2010 by the Centre for Suicide Research in Oxford, England aimed to identify which antidepressant drugs were more closely linked to suicide or attempted suicide. To this end, the researchers combed through coroner’s reports and hospital admission records in six hospitals in the United Kingdom and Wales from 2000 to 2006.

What they found was that TCAs had the overall highest toxicity and the highest rate of fatality compared to SSRIs and all other classes of antidepressants.

This was especially true for the TCA drugs Prothiaden (dosulepin) and Silenor (doxepin). Of the SSRIs, Celexa (citalopram) was seen to have the highest toxicity and fatality rate.

It was hoped that by better understanding the associative risks, doctors would be more selective when prescribing antidepressants to persons at high risk of self-harm and suicide.

Suicidal Thoughts

For its part, the U.S. Food and Drug Administration has required that there be a black box warning on all antidepressants due to an increased risk for suicidal thoughts in children, teens, and young adults. In this regard, persons taking SSRIs are seen to be at slightly greater risk.

Suicidal thoughts are more likely to occur in the early days and weeks of treatment, requiring close supervision by parents, guardians, or family members until the effects of the drug fully kick in.

On the flip side, the abrupt termination of antidepressants is seen to increase the risk of suicide by 500 percent and the risk of attempted suicide by 700 percent. The gradual tapering off of the drug is needed to avoid this.

How to Tell If Someone Has Overdosed

Whether a person has accidentally or intentionally overdosed, the symptoms will typically be mild and non-specific in the first hour or two and progressively worsen in the convening hours.

The first signs are usually nausea, drowsiness, dry mouth, agitation, headache, vomiting, and diarrhea, all of which can easily be attributed to other causes. One of the earliest red flags may be a rapid and irregular heartbeat (tachycardia), a condition not commonly seen in young people.

If an overdose is suspected, the combination of these symptoms would warrant an immediate visit to the emergency room.

As the more toxic effects emerge, symptoms may include:

  • Confusion
  • Delirium
  • Hallucinations
  • Tremors
  • Involuntary eye movement
  • Increasingly worsening heart pace (dysrhythmia)
  • Respiratory distress
  • Seizures
  • Unconsciousness
  • Coma

Seizures, cardiac dysrhythmia, respiratory distress, and coma are considered the most-threatening complications.

Emergency Treatment for an Overdose

Emergency medical interventions would include efforts to pump the person’s stomach and provide activated charcoal to absorb the remaining drugs.

Both of these should be done within the first hour. Intravenous sodium bicarbonate and other medications would be prescribed to counteract the effects of the drug. Dialysis is rarely effective in persons who have overdosed on antidepressants.

Once the person is stabilized, he or she would be placed in an intensive care unit (ICU) for no less than 12 hours and released only after an electrocardiogram (ECG) remains normal for 24 hours. Before release, the appropriate psychiatric and/or substance abuse interventions would be pursued whether the overdose was intended or not.


Friedman, R. "Antidepressants' Black-Box Warning - 10 Years Later." New England Journal of Medicine. 2014; 371: 1666-68; DOI: 10.1056/NEJMp1408480.

Hawton, K.; Cooper, J.; Waters, K. et. al. "Toxicity of antidepressants: rates of suicide relative to prescribing and non-fatal overdose." British Journal of Psychiatry. 2010; 196(5): 354-58; DOI: 10.1192/bjp.hp.109.070219.