Ever wondered if your friends actually like you?
It's a pretty sad thought and not one that will perk you up, but it turns out you only have about half the number of friends you thought you did.
New research, which could be the most depressing ever, found 50 per cent of friendships were unrequited.
A large number of people who knew each other were asked to rank their friendships, and guess how their "friend" ranked them back.
Most people assumed their "friend" would rank them the same way, but they were mistaken.
Some people had "close friends" who only considered them as an acquaintance - told you it was depressing.
"When one considers another individual as a 'friend', the common expectation is that this other individual also thinks of them as friends," researchers said.
"In reality not all friendships are reciprocal.
"We find that the vast majority of friendships are expected to be reciprocal, while in reality, only about half of them are indeed reciprocal."
If you're one of those stubborn people who is thinking "fine, I don't need friends anyway" it is advised that you hold on to the 50 per cent of people who reciprocate your friendship because they are actually really important.
Dr Susan Krauss Whitbourne, a professor of psychological and brain sciences, said there were 15 reasons to hold onto your buddies.
She said in a Psychology Today article our friends affected us more than we realised and friends helped shape who we all are today.
"You are even the product of the friends who are no longer your friends," she said.
Friends can also give you life skills, giving you another good reason to keep them around.
Dr Krauss Whitbourne said friendships could sharpen your mind, make you generally happier and inspire you to achieve your goals.
They can also help you meet a partner and can be part of the reason for living a long and healthy life.
Surprisingly, your friends from your teenage years have a massive influence on your romantic life.
According to Dr Krauss Whitbourne, they teach you to develop long-term bonds, a skill you will need if you're looking for a life partner.
Friends can also help you see your priorities, as many choose mates that are similar to them and they also make you less lonely.
If you're wondering now if somebody is legitimately your friend, there are a few telltale signs.
The researchers, who published their discoveries in the PLOS ONE journal, looked at how friendships changed how much people exercise.
If somebody doesn't really consider you a friend, they're less likely to influence your physical activity.
Also, if your friend has more friends than you, you're probably less important to them.
There is some good news, if you and your mate have a large number of mutual friends, you probably have a solid bond.