Caffeine is a stimulant found in many beverages, such as coffee, soda and energy drinks. Antidepressants are a specific class of prescription medication designed to improve mood. The major classes of antidepressants are selective serotonin reuptake inhibitors, or SSRIs; tricyclic antidepressants; monoamine oxidase inhibitors, or MAOIs; and so-called designer antidepressants. According to MayoClinic.com, SSRIs are the most commonly prescribed antidepressants because of the low risk of side effects and toxicity.
According to Brown University, caffeine is mildly addictive and consumed by up to 90 percent of the people in the world. The stimulant activates neurons, which then release adrenaline. Caffeine also increases levels of dopamine, a neurotransmitter in the brain responsible for mood, energy and metabolic functions. The caffeine effects are generally mild. High amounts of caffeine can cause insomnia, restlessness, anxiety and headaches. Caffeine also acts as a diuretic and dehydrates the body. In pregnant women, caffeine may increase the risk of miscarriage.
The effects of antidepressants vary widely depending on the exact drug. SSRIs, such as sertraline, escitalopram and fluoxetine -- sold as Zoloft, Lexapro and Prozac, respectively -- target the specific neurotransmitter serotonin. These medications seek to increase serotonin in the brain to improve mood and promote a feeling of calmness. SSRIs can reduce symptoms in moderate to severe cases of depression, according to MayoClinic.com. Side effects from antidepressants are usually mild and subside within one to four weeks. Typical side effects include nausea, increased appetite or weight gain, sexual side effects, fatigue or insomnia.
Caffeine and Antidepressants
Generally, caffeine does not interfere with antidepressants. For example, commonly prescribed SSRIs and caffeine have no negative interaction, according to Drugs.com's interaction checker. Caffeine can, however, raise blood pressure. Certain antidepressants, such as venlafaxine, sold as Effexor, also raise blood pressure, so avoid caffeine when taking this medication. If you feel anxious or restless from your antidepressant, caffeine can worsen those side effects. If your antidepressants cause sedation, a small amount of caffeine can help alleviate the effects.
Consult your physician or pharmacist about any potential interaction between caffeine and antidepressants. According to the National Institute of Health's MedlinePlus, three servings of coffee or five servings of soft drinks is a moderate amount of caffeine. If you have an anxiety or panic disorder, reduce your caffeine consumption or eliminate it completely. Some over-the-counter medications, especially pain relievers, and herbs also contain caffeine. If you are trying to reduce your caffeine intake, avoid caffeine from those sources as well.