Topic summary contributed by volunteer(s): Lauren and Dawn
Depression can be a debilitating mental illness that sometimes ends in suicide. An estimated 8.7% of Americans take antidepressants to battle depression.
How do antidepressants work?
Antidepressants use different mechanisms to increase the levels of the neurotransmitters serotonin, norepinephrine and dopamine in the brain. Many researchers believe that a chemical imbalance of these neurotransmitters may lead to depression.
Tricyclic antidepressants block the uptake of norepinephrine and dopamine while Selective Serotonin Reuptake Inhibitors (SSRIs) block the reuptake of serotonin by neurons. Monoamine Oxidase Inhibitors (MAOIs) inhibit the action of the major enzyme, monoamine oxidase, which breaks down serotonin before it can be taken up by neurons.
Antidepressants take a significant amount of time to decrease depressive symptoms. Drugs such as Prozac and Celexa take a minimum of 4 to 6 weeks to be effective, whereas the drug Paxil takes up to 12 weeks.
Meta-analyses have shown that antidepressants are effective at reducing mild to moderate depressive symptoms, but also revealed that sugar pills, or the placebo effect, were about as effective as the drugs. So there was no clinically significant advantage for prescribing antidepressants instead of a sugar pill. For severe depression, antidepressants performed better than placebos.
Researchers found that many of the studies demonstrating a lack of clear advantages to the drugs over placebos were never published, and in some cases, may have even been concealed by the pharmaceutical industry. In the multi-billion dollar antidepressant market, there are some powerful industry influences at work.
Side Effects of Antidepressants
Antidepressants have some powerful negative side effects. Up to three-quarters of individuals who take antidepressants experience sexual dysfunction. Other side effects include long-term weight gain, insomnia, nausea and diarrhea. Withdrawal symptoms are not uncommon, and those who take antidepressants are more likely to become depressed in the future.
Widespread antidepressant use also has consequences for the environment. Some of the drugs’ metabolites are excreted in the urine of people taking antidepressants, and ends up in our waterways. Worse still, the drugs have been found to bioaccumulate in the flesh of fish as well as their brains.
Effectiveness of Antidepressants vs. Lifestyle Changes
Plant-based diets have shown promising results when compared to antidepressants. Just three servings of vegetables per week cut the risk for major depression by 60%. As well, drugs can take months to take effect, whereas mood can improve in as little as two weeks by removing meat, fish, poultry and eggs from the diet.
Certain plants have also been found to have depression-associated enzyme inhibitors. The tobacco plant is one of them, which may explain what makes smokers feel good. Saffron capsules have been shown to be as effective as the SSRI Prozac in a six-week trial with clinically depressed participants. Other plants, including apples, berries, grapes, kale, onions and green tea, have phytonutrients that may affect brain biology enough to improve mood without the negative consequences of tobacco or the side effects of antidepressants.
Exercise has also been shown to have antidepressant effects.