Many Psychiatric Drugs Have Serious Effects on Body Weight

Patients are not always warned about the weighty impact of antipsychotics, antidepressants and stimulants

By | |

Unexpectedly losing a loved one launched 18-year-old Debra* into an episode of major depression, triggering dangerous delusions that landed her in a hospital. Her doctor immediately started her on an antidepressant and on risperidone (Risperdal), an antipsychotic. In little more than a month, her weight shot up by 15 pounds. “Gaining weight made it even more difficult for me to want to leave my house because I felt self-conscious,” Debra says.

In the medical community, antipsychotics are well known to cause significant weight gain. Gains of 20 to 35 pounds or more over the course of a year or two are not unusual. Debra's doctor never warned her, though, leaving her feeling like she was losing herself both mentally and physically. The situation is not uncommon, according to psychiatrist Matthew Rudorfer, chief of the somatic treatments program at the National Institute of Mental Health, who points out that although the U.S. Food and Drug Administration carefully tracks acute side effects such as seizures, it pays less attention to longer-term complications such as weight change. Perhaps taking their cue from the FDA, doctors tend to downplay weight-related risks that accompany many psychiatric drugs, Rudorfer says. But for Debra and many others, these side effects are not trivial. The three types of psychiatric drugs that can seriously affect body weight are reviewed below.

Antipsychotics

As Debra's case demonstrates, antipsychotics are by no means reserved for treating people with schizophrenia. A growing body of evidence supports the use of antipsychotics in combination with antidepressants for addressing treatment-resistant depression.

Studies show that metformin, a diabetes drug, and topiramate, an anticonvulsant, can be effective at reducing antipsychotic-induced weight gain. Behavioral interventions may also help people maintain their weight while on these drugs, according to a 2015 study of 200 people with severe mental illness who had been taking an antipsychotic for at least one month and were overweight or obese. The study found that a personalized diet and exercise plan was helpful to 40 percent of the participants, who dropped at least 5 percent of their body weight after six months of dieting and exercise and six months of maintenance.

Antidepressants

Depression itself, however, is linked with an increased risk of becoming obese, according to a 2010 analysis that included more than 58,000 people. The reverse holds true as well, the study found; obese people are more likely to suffer from depression. As a result, “it is easy to misattribute the weight gain to a medicine when, in fact, it may largely be related to the illness being treated,” cautions Richard Shelton, a professor of psychiatry at the University of Alabama at Birmingham.

Stimulants

For people who are prescribed stimulants to treat psychiatric conditions such as ADHD, however, weight loss comes as a side effect. A 2014 study that included 163,820 children between the ages of three and 18 showed that those taking stimulants to treat their ADHD had slower rates of growth from early childhood to the middle years compared with control subjects who had no history of ADHD or stimulant use. Yet the authors noted that stimulant-treated youngsters with ADHD experienced a growth rebound in late childhood, resulting in a higher weight-to-height ratio in adolescence compared with controls. This association may explain the previously observed link between ADHD in childhood and obesity in adulthood.

see also: