Facebook's initial public offering of stock is likely to make a lot of developers and designers of the site very wealthy. But for many users, frequent Facebooking may not be so beneficial.

According to three new studies, Facebook can be tough on mental health, offering an all-too-alluring medium for social comparison and ill-advised status updates. And while adding a friend on the social networking site can make people feel cheery and connected, having a lot of friends is associated with feeling worse about one's own life.

The thread running through these findings is not that Facebook itself is harmful, but that it provides a place for people to indulge in self-destructive behavior, such as trumpeting their own weaknesses or comparing their achievements with those of others.

The status (update) trap

Take status updates. Most people know that their Facebook friends tend to craft these online-wall memos on what they're up to in a way that puts their lives in the best light, said Mudra Mukesh, a doctoral candidate in marketing at the Instituto de Empresa in Madrid. But when it comes down to actually using the site, reading other people's status updates still makes Facebookers feel worse. [Facebook's Global Reach (Infographic)]

In research presented earlier this month at the annual meeting of the Society for Personality and Social Psychologists (SPSP) in San Diego, Mukesh and her co-author Dilney Goncalves found that when people think about the last time someone asked to friend them on Facebook, they get a boost in feelings of belonging and social connectedness ­— the kind of feeling that makes people "sing 'Kumbaya,'" Mukesh told LiveScience.

But once you've collected all those friends, viewing their status updates is a downer, Mukesh said. When asked how they felt about their place in life and their achievements, people with lots of Facebook friends gave themselves lower marks if they'd just viewed their friends' status updates, compared with people who hadn't recently surfed the site.

For people with just a few friends, viewing status updates wasn't a problem.

"A small number of friends means a low probability of viewing others showing off," Mukesh said. For people with lots of friends, though, the Facebook Newsfeed turns into a parade of good news about other people's live: promotions, engagements, weddings and new babies. Even if someone knows intellectually that people use Facebook to show off, Mukesh said, all of this information can make them feel worse about their own achievements or lack thereof. [10 Technologies That Will Transform Your Life]

(In Mukesh's study, 354 friends was the cut-off point for when participants started to feel bad about viewing status updates. But that's not a universal number, she cautioned, just the number that applied given the statistics of her sample.)

Comparisons and competitions

In another study presented at the SPSP conference, researchers at the University of Houston surveyed college students and found that time spent on Facebook is linked to depressive symptoms. That doesn't mean Facebook causes depression, but that depressed feelings and lots of Facebooking tend to go hand in hand, for whatever reason. For young men, the study found, the link seemed to be a tendency to compare oneself with others.

"It appears as if males, when they socially compare themselves on Facebook, they tend to experience depressive symptoms," study researcher and University of Houston doctoral student Mai-Ly Nguyen told LiveScience.

In this case, Facebook seems to be a new medium for men to compete with one another, Nguyen said. Outside the digital realm, men often compare themselves with one another, she said. It may be that women more often use the site to connect with one another and men to compete with one another.

Woe is me

Some people, however, don't use their Facebook status updates to pump themselves up. Instead, they complain.

People with low self-esteem view Facebook as a safer place to express themselves than in face-to-face interactions, according to new research published in the March issue of the journal of Psychological Science. All this venting may actually alienate friends.

Researchers led by Amanda Forest of the University of Waterloo in Ontario collected recent status updates from 117 participants who also reported their average time spent on Facebook and answered questions to reveal their self-esteem levels. Some statuses were chipper, such as "[Poster] is lucky to have such terrific friends and is looking forward to a great day tomorrow!" Others wallowed in bad news: "[Poster] is upset b/c her phone got stolen :@."

Next, the researchers had another group of participants read the status updates and rate how much they liked the person who wrote each. Unsurprisingly, people responded more positively to posters whose updates were positive.

Of course, you'd expect friends to be a little more caring than strangers. So the researchers set up another experiment in which they collected recent status updates from 98 undergraduates and also asked the students to submit the number of likes and number of comments on each.

It turned out that for users with high self-esteem, a negative post garnered more responses than a positive one, presumably because those people's friends were concerned about the out-of-character update. For users with low self-esteem, though, negative posts seemed to exhaust friends: They got few responses.

"Indeed, [low-self-esteem users'] friends rewarded their posts with more validation and attention the more positive they were, perhaps trying to encourage this atypical behavior," Forest and her colleagues wrote.

Forgoing Facebook?

The takeaway of all this work is not to dump your Facebook account — the site has its benefits, some psychological. But researchers suggest being mindful about your online social life, just as most people are about friends in the real world.

"You have to be careful," said University of Houston psychologist Linda Acitelli, who advised Nguyen on the social comparison study. "I think parents, especially if they have teenage kids, need to be monitoring how much time they spend on Facebook."

Because Facebook provides more opportunities to peer into others' lives, it helps to keep Facebook pitfalls in mind, according to the Instituto de Empresa's Mukesh. She found that reminding people in the moment of what they already know ­— that people brag on Facebook — can ease the self-recriminations that come with hearing about friends' accomplishments.

"At the end of the day, have more friends, there's no problem with that. Just be sure to remember that when you start feeling crappy about your life, think about the fact that you have a large number of friends and that increases your probability of viewing more ostentatious information," Mukesh said. "So, it's not you, it's them."

You can follow LiveScience senior writer Stephanie Pappas on Twitter @sipappas. Follow LiveScience for the latest in science news and discoveries on Twitter @livescience and on Facebook.