If drugs, what kind?

Most respondents—78 percent—received medication for their depression or anxiety, reflecting the tremendous growth of the use of antidepressant drugs in the past 15 years. According to IMS Health, a group that monitors drug sales, U.S. doctors prescribed $9.9 billion worth of antidepressants in 2009, a 3 percent growth over the previous year. They're the third most prescribed class of drugs in the country, after cholesterol-lowering drugs and codeine-based painkillers, thanks at least in part to years of aggressive marketing.

Drugmakers spent almost $300 million in 2009 on ads for two newer antidepressants alone: duloxetine (Cymbalta: "When you're depressed, where do you want to go? Nowhere.") and desvenlafaxine (Pristiq: "I feel like I have to wind myself up just to get out of bed.").

Reflecting national trends, most recipients of medication in our survey got an SSRI (selective serotonin reuptake inhibitor) such as fluoxetine or sertraline; many others got an SNRI (serotonin and norepinephrine reuptake inhibitor) such as venlafaxine or duloxetine. The drugs alter the levels of certain brain chemicals, or neurotransmitters, that carry signals between nerve cells. The Food and Drug Administration has approved SSRIs and SNRIs as standard first-line treatments for depression and anxiety disorders.

Forty-seven percent of respondents got their prescription from a psychiatrist; the rest obtained it from their primary-care physician, whom they saw separately or as an adjunct to talk therapy with a mental-health professional. That's consistent with national data that show primary-care doctors, not psychiatrists, prescribe the majority of SSRIs and SNRIs and have done so for at least the last five years.

One size doesn't fit all

Some SSRIs and SNRIs are promoted for particular types of anxiety, such as social anxiety or obsessive-compulsive disorder. But clinical evidence shows that they work equally well for each major form of anxiety. And individuals don't all react the same way to these drugs, so it can take some trial and error to find the one that works best for you. Among respondents who took medication for anxiety or depression, the median number of drugs tried was three. Respondents who tried three medications had slightly better outcomes than those who tried fewer or more, suggesting that trial and error is an important part of pharmaceutical treatment.

Expect some side effects

As with all drugs, antidepressants have side effects. But our findings suggest they can be a lot more common than what's reported in the package inserts you get when you fill your prescription. For example, 31 percent of people we surveyed who took SSRIs and 36 percent of those who took SNRIs reported a decrease in sexual interest or ability (see Readers Rate Antidepressants). That's more than double the rate reported in studies sponsored by drug companies, which can carefully choose their participants and tend to pick those least likely to experience adverse effects.

Interestingly, men reported more sexual side effects than women, while women complained more often about weight gain. It may be a true physiological difference, or women may simply be more bothered by weight gain and men by sexual difficulties.

The sexual side-effect rates from the current survey are lower than those we found in 2004, when up to 53 percent of respondents reported them. "It's possible that health-care providers are either prescribing antidepressants that are less likely to cause these problems, such as bupropion (Wellbutrin and generic) or are adding another drug in as an antidote to help counteract the sexual side effects," said Anita Clayton, M.D., a professor of psychiatry and obstetrics and gynecology at the University of Virginia.

For many respondents, side effects proved more than mere annoyances: Of those who'd stopped taking an antidepressant, 33 percent said they did so because of intolerable side effects. Still, the drugs helped a lot for about half of the people who took them and at least somewhat for another 30 percent. And people who took the drugs in conjunction with talk therapy fared especially well.

Use tranquilizers selectively

For the 58 percent of respondents who experienced anxiety, we also asked about benzodiazepines, an older class of anti-anxiety drugs that includes alprazolam (Xanax and generic) and lorazepam (Ativan and generic). About one-quarter had tried a benzodiazepine; of those, 57 percent said it helped "a lot." The drugs can cause dizziness and drowsiness, though, and unlike SSRIs and SNRIs, their daily use can lead to dependence. Our medical consultants say they're best for short-term "rescue" situations, such as quelling a panic attack or helping a fearful flyer board a plane.

What to do

Consumer Reports Best Buy Drugs, a public education project that generates drug recommendations based on safety, efficacy, and price, says that generic bupropion, citalopram, fluoxetine, and sertraline are among the best initial options to consider for depression. Ask your doctor whether you can start at the lowest dose possible. If the first drug hasn't helped within six to eight weeks, talk with your doctor about increasing the dose or switching to a different drug. Don't take bupropion if you have a history of seizures, since it carries a risk of seizures at high doses. Discuss with your doctor the potential side effects and how long you'll probably need to take the drug (most respondents had been taking theirs for at least two years). Don't stop taking an antidepressant suddenly, which could cause withdrawal symptoms.