The side effects of antidepressants can differ significantly, ranging from weight fluctuations to alterations in blood pressure. Medical professionals need to consider these factors when selecting the most appropriate medication among the numerous options available.

About 10% of individuals in Europe and the US utilize antidepressants to address symptoms including depression and anxiety. Withdrawal symptoms may not be as prevalent as assumed, yet some studies indicate physical side effects associated with these medications. The specific side effects linked to each drug, however, remain unclear.

Diving deeper into the research, Toby Pillinger and his team from King’s College London examined data from 151 randomized controlled trials and 17 reports from the US Food and Drug Administration. These studies encompassed 30 different antidepressants, assessing their efficacy and side effects relative to a placebo over roughly eight weeks for various mental health conditions.

“The strength of these studies lies in their placebo-controlled and randomized design, allowing us to confidently attribute the observed differences to the medications,” Pillinger states.

The analysis revealed that certain medications were linked to weight loss, while others caused weight gain. For instance, maprotiline was associated with an average weight gain of approximately 1.8 kg, whereas agomelatine was linked to an average weight loss of about 2.4 kg.

The research additionally indicated that fluvoxamine led to an average decrease in heart rate of 8 beats per minute (bpm), while nortriptyline raised it by 13 bpm. Notably, nortriptyline also lowered systolic blood pressure (the pressure during heart contractions) by 3 to 7 millimeters of mercury (mmHg), whereas doxepin elevated blood pressure by nearly 5 mmHg, which may have wider health implications. “For every 1 mmHg increase in blood pressure, the risk of stroke rises by 1%,” remarks Oliver Howes, also from King’s College London.

Other medications like paroxetine, duloxetine, desvenlafaxine, and venlafaxine have been linked to increased cholesterol levels. It remains uncertain if these side effects intensify, diminish, or stabilize after the initial eight-week period.

Although observational studies have raised concerns regarding the potential impact of antidepressants on electrolyte levels, particularly sodium—as it may influence heart rhythms—”our study indicates that sodium isn’t an issue at all,” Pillinger comments.

In the UK, over 92 million antidepressants were prescribed last year, with approximately 85% being either sertraline, mirtazapine, fluoxetine, amitriptyline, citalopram, or venlafaxine. Among these, four exhibited relatively favorable profiles for various evaluated factors; however, amitriptyline was noted for increasing body weight, heart rate, and blood pressure, while venlafaxine was found to elevate heart rate, blood pressure, and cholesterol levels.

“This information is immensely useful for both physicians and patients,” remarks Mahyar Etminan from Epilytics, an epidemiological consulting firm in Vancouver. “This data can be integrated into an application, enabling doctors to identify which medications to avoid for individuals with high cholesterol or cardiovascular issues. It provides physicians with greater flexibility in selecting the most suitable antidepressant for their patients.”

Pillinger mentions that his team is developing a digital tool that features a drop-down list of common side effects associated with antidepressants, assisting healthcare providers in determining which medications to avoid or whether reducing dosage could be advantageous. “The essential goal is to find the most appropriate drug for each individual and tailor prescriptions accordingly,” Pillinger explains.

However, John Ioannidis, a researcher at Stanford University, cautions that their findings could be skewed if only studies demonstrating side effects were included. Some research may not have reported any adverse effects, thus excluding pertinent data from the meta-analysis.

He also points out that patients typically remain on antidepressants for at least eight weeks, often for several years. “If such an impact exists over a more extended period, it necessitates different long-term studies to validate its relevance,” Ioannidis asserts.

Pillinger acknowledges the possibility of bias but believes they have compiled the majority of relevant data. He recognizes the need for long-term study analysis and is in the process of conducting it, mentioning that around 75% of trial participants have been white. Nonetheless, he believes the trends identified will likely become clearer over extended studies and may extend to other demographics.

Prior research has indicated that some antidepressants, such as venlafaxine, are associated with long-term blood pressure increases. He also notes that rapid weight gain might persist. “Once weight is gained, it becomes challenging to lose it again,” he states.

However, due to the effectiveness of antidepressants, those worried about side effects should not discontinue their medication, according to Howes. “This is a nuanced issue and an individual decision that considers your unique risk factors and benefits. If concerned, consulting with your physician is advisable.”