Are the Side Effects of Antidepressants Underestimated?

New research reveals a wide range of adverse side effects from antidepressants.

Posted Feb 26, 2014

A University of Liverpool study released on Feb. 26 has shown that thoughts of suicide, sexual difficulties, and emotional numbness as a result of taking antidepressants may be more widespread than previously thought.

In a survey of 1,829 people who had been prescribed antidepressants, the researchers found large numbers of people—over half in some cases—reported psychological problems due to their medication. There is growing concern among researchers about the ratio of benefits to detriments resulting from the use of antidepressants.

One in ten people in some countries are now prescribed antidepressants each year. Psychologist and lead researcher, Professor John Read from Liverpool University's Institute of Psychology, Health and Society, said: "The medicalization of sadness and distress has reached bizarre levels.”

The new study titled "Adverse Emotional and Interpersonal Effects Reported by 1829 New Zealanders While Taking Antidepressants" was published in the journal Psychiatry Research. 

Adverse Psychological Side Effects of Antidepressants

Each person in the New Zealand study completed an online questionnaire which asked about twenty adverse effects. All of the participants in the study had been on antidepressants in the last five years. The survey factored in people's levels of depression and asked them to report on how they had felt while taking the medication.

Over half of people aged 18 to 25 in the study reported suicidal feelings. In the total sample there were large percentages of psychological and interpersonal side effects that included:

  • Sexual difficulties. (62%)  
  • Feeling emotionally numb. (60%)
  • Feeling not like myself. (52%)
  • Reduction in positive feelings. (42%)
  • Caring less about others. (39%)
  • Withdrawal effects. (55%)  

On the positive side, a majority of people reported that the drugs had helped alleviate their depression at some point. Professor Read said, "While the biological side effects of antidepressants, such as weight gain and nausea, are well documented, psychological and interpersonal issues have been largely ignored or denied. They appear to be alarmingly common."

Read concludes, "Effects such as feeling emotionally numb and caring less about other people are of major concern. Our study also found that people are not being told about this when prescribed the drugs. Our finding that over a third of respondents reported suicidality as a result of taking the antidepressants suggests that earlier studies may have underestimated the problem."

Adverse Physical Side Effects of Antidepressants

In April 2012 researchers from McMaster University published a detailed analysis of the impact of antidepressants on the entire body. The researchers concluded that commonly prescribed antidepressants appear to be doing patients more harm than good.

"We need to be much more cautious about the widespread use of these drugs," warns Paul Andrews, an evolutionary biologist at McMaster University and lead author of the article, titled "Primum non nocere: An Evolutionary Analysis of Whether Antidepressants do More Harm than Good” which was published in the online journal Frontiers in Psychology.

Andrews and his colleagues examined previous patient studies into the effects of antidepressants and determined that the benefits of most antidepressants—even taken at their best—compare poorly to the risks, which include premature death in elderly patients. "It's important because millions of people are prescribed antidepressants each year, and the conventional wisdom about these drugs is that they're safe and effective," said Andrews.

Andrews and colleagues found that while antidepressants can be effective in reducing depressive symptoms, they also increase the brain’s susceptibility to future episodes of depression after they have been discontinued.

Their report found that contrary to a widely held belief in psychiatry, studies that purport to show that antidepressants promote neurogenesis are flawed. In fact, the researchers believe that antidepressants may cause neuronal damage and mature neurons to revert to an immature state, both of which may explain why antidepressants also cause neurons to undergo apoptosis (programmed death).

The researchers at McMaster University found that antidepressants have negative health effects that include these elevated risks:

  • Developmental problems in infants.
  • Problems with sexual stimulation and function and sperm development in adults.
  • Digestive problems such as diarrhea, constipation, indigestion and bloating.
  • Abnormal bleeding and stroke in the elderly.

The authors reviewed three recent studies showing that elderly antidepressant users are more likely to die than non-users, even after taking other important variables into account. They conclude that the higher death rates indicate that the overall effect of these drugs on the body is more harmful than beneficial. Although millions of people are prescribed antidepressants every year, and while the conclusions may seem surprising, Andrews says much of the evidence has long been apparent and available.

"The thing that's been missing in the debates about antidepressants is an overall assessment of all these negative effects relative to their potential beneficial effects," he says. "Most of this evidence has been out there for years and nobody has been looking at this basic issue."

In previous research, Andrews and his colleagues had questioned the effectiveness of antidepressants even for their prescribed function, finding that patients were more likely to suffer relapse after going off their medications as their brains worked to re-establish equilibrium.

Conclusion: Weigh the Pros and Cons of Antidepressants With Your Doctor

There is growing evidence which suggests that, in general, antidepressants are neither totally safe nor totally effective—in some cases they appear to do more harm than good. That said, when deciding whether to take any medication it is important to educate yourself—speak with your doctor—and weigh the potential pros and cons before beginning, prolonging, or discontinuing the use of any pharmaceutical.

Paul Andrews believes that patients should be advised that prolonged use might cause mild cognitive impairment and interfere with tasks that require highly focused concentration, such as driving, which may increase the risk of accidents. Patients should also be advised that antidepressants might trigger even more severe depressive episodes when they are discontinued.

According to researchers, patients should be informed that current research suggests that unless they have very severe depression, the symptom reducing effects of antidepressants can be modest and may not be clinically significant.

All patients should be advised of the possible bleeding risks, and physicians should exercise particular caution in prescribing these drugs in conjunction with other diuretic or anti-thrombotic medications. The evidence of harm is strongest in the elderly, who should be advised of the risks of falling, hyponatremia, bleeding, stroke, and death. Unless there are rapid-onset adverse side effects, antidepressant therapy usually lasts for months.

With the long-term effectiveness of the intended function of antidepressants in question, Paul Andrews concludes that it is important to look more critically at continuing their use. "It could change the way we think about such major pharmaceutical drugs," he says. "You've got a minimal benefit, a laundry list of negative effects—some small, some rare and some not so rare. The issue is: does the list of negative effects outweigh the minimal benefit?"

If you’d like to read more on this topic, check out my Psychology Today blog posts:

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