Lancet study: Antidepressants vary widely in weight and heart effects

Antidepressants: 30 drugs, 2 kg weight change, and 20 bpm difference

One mental health issue, thirty pharmacological solutions, and a range of side effects stretching from sedation to cardiac alarm. A meta-analysis published in The Lancet, cited as a reference in discussions on these treatments, compares the physiological profile of around thirty antidepressants and concludes that differences between them are "heterogeneous and frequent": from weight variations of up to 2 kilos in eight weeks to heart rate changes exceeding 20 beats per minute, including blood pressure fluctuations of up to 10 mmHg.

This data is striking because it breaks a comfortable assumption: that all antidepressants work and are tolerated equally. They do not. Mirtazapine, amitriptyline, or maprotiline appear among those adding the most weight —up to 2 kilos in eight weeks— while agomelatine is associated with a loss of up to 2.5 kilos, with a harsh side-effect profile: anxiety, irritability, agitation, nightmares, emotional variability, and risk of suicidal thoughts. The choice of drug, therefore, is not a minor detail.

What side effects do antidepressants have according to the study?

The work, focused on physical impact, organizes effects into several areas. Regarding weight, differences between compounds are notable and go in opposite directions. In terms of heart rate, nortriptyline accelerates the pulse while fluvoxamine slows it down, with a gap exceeding 20 beats per minute between extremes. For blood pressure, doxepin raises it and nortriptyline lowers it, with variations of up to 10 mmHg. And in the cardiometabolic field, the study detects alterations in glucose and lipids which, combined with a poor diet and sedentary lifestyle, paint an unflattering scenario.

The conclusion drawn is not that antidepressants are useless, but that they are drugs with very different profiles and that the choice between them should weigh more than it does in the consultation room. The complete material, with the comparative table of the thirty compounds, allows seeing which molecule is associated with which imbalance and to what extent the margin for choice is real.

The debate: between the pill that saves and the pill that dulls

The discussion generated by this issue in recent months is not about whether antidepressants work, but when, for whom, and at what cost. One current argues that in severe cases —major depression, bipolar disorder, schizophrenia, extreme anxiety— medication has saved lives and that the problem is not the drug but the lack of trinc-up. "Antidepressants have saved more than one life," summarizes one intervention, adding that mood stabilizers like lithium or valproic acid are essential in certain diagnoses.

Opposing this, another line of opinion holds that the pill has become the automatic response to any discomfort, turning the patient into a functional ghost. "Being pill-popping is not living, it is being a ghost," notes a message describing the effect as a loss of identity: the person responds to stimuli, meets expectations, but ceases to be themselves. Some go further, claiming that antipsychotics and antidepressants only serve so the sick person does not bother their environment.

Lithium, bupropion, and valproate: nuances that get lost

The exchange becomes more technical when pharmacological details enter. Lithium is the only "pure" mood regulator mentioned, effective for stabilizing the highs and lows of bipolar disorder, but with a known problem: at medium and high doses, it easily affects the thyroid and, used for years, can damage the kidneys. Valproic acid, lamotrigine, carbamazepine, and oxcarbazepine belong to the group of anticonvulsants, proven useful also for regulating mood. And bupropion appears as the antidepressant that does not crush libido, a detail that is not minor for those taking it.

Also entering the conversation is low-dose lithium orotate, five milligrams daily, which some use as a supplement. The technical answer is that, at that dose, it is considered safe and crosses the blood-brain barrier better than the carbonate used in psychiatry, but it enters the realm of supplements, where regulation is scarce. A warning worth keeping in mind.

Why are they prescribed so much and to whom?

The volume of prescription is another front of the issue. Data from Spain's National Health System handled in the conversation indicate that women consume between 1.5 and 3 times more antidepressants than men, a pattern repeated in anxiolytics and hypnotics and accentuated with age. The lingering question is whether this reflects a greater real prevalence of disorders or a different medicalization of distress based on gender.

Some point to healthcare pressure: ten-minute consultations, protocols pushing prescriptions, and professionals who lack time or tools to explore non-pharmacological causes. The recurring complaint is that no one checks diet, zinc, copper, or vitamin B levels, nor rule out parasites before reaching for pills. A specific case illustrates this: months of tongue discomfort without the health center agreeing to perform specific tests, forcing the patient to pay privately.

Suspicion over evidence and the role of industry

In the area of evidence, distrust is explicit. One intervention claims that "no antidepressant works" and that all studies rely on the same original work, which turned out to be fraud. This is a claim circulating strongly in the debate, though no concrete reference supporting it is provided. What is mentioned is the relationship between industry and prescribers: gifts, trips, and conferences for those meeting prescription targets, a mechanism argued to condition drug choice beyond clinical evidence.

The conclusion repeated across various parts of the conversation is that the problem is not just the drug, but the system prescribing it. And that the alternative —exercise, diet, therapy, life order— is not offered because it generates no revenue. A thesis that, with more or fewer nuances, runs through the entire exchange.

What happens when medication is stopped without control?

The issue has a face that should not be overlooked: withdrawal. Several interventions warn that stopping medication on one's own can be counterproductive, especially in severe disorders. Schizophrenia and bipolar disorder appear as cases where unsupervised suspension has serious consequences. The repeated recommendation is that any regimen change be made with a professional, even if that professional is not always up to par.

The closing of the matter remains open. Evidence on side effects is solid and differences between drugs, notable. What is unresolved is how this translates in the consultation: how many patients receive the drug appropriate for them, how many receive the one dictated by protocol, and how many bear side effects no one warned them about. How many of those taking antidepressants know exactly what they are taking and why?