Your best friend broke things off with her boyfriend a month ago, and she still feels guilty about ending things. You've tried to get her to go to the movies, spend time with friends and join you for lunch, but she feels she doesn't deserve to be happy. If you know someone who is stuck in a negative spiral, choose your words carefully to help lift her up.

Like a Child

Ask your friend to observe a baby or young child, and ask whether she thinks that the infant or toddler deserves to be happy. When she answers "Yes," ask her why she doesn't deserve the same. We all start as children with a sense of being happy, but the feeling somehow gets lost as we get older, says Dr. David Simon, in the "Psych Central" article "You Don't Deserve to be Happy? An Interview with David Simon, M.D." We start to make choices that are "safe" without regard to whether they make us happy. For example, if your friend feels guilty that she should have stayed with her boyfriend, tell her that her happiness is just as important as his.

The Right Direction

Tap into your friend's desire to be happy -- and he will be more likely to acknowledge that he deserves to feel that way. For example, Simon suggests asking the other person to describe two points on a map. The first is his current situation, and the second is how he would envision his life if everything was the way he wanted it to be. For example, if your friend thinks he doesn't deserve to be happy and has low self-esteem around girls, ask him what things would be like if he were confident and had lots of dates. Then, discuss the trajectory that would take him from point A to point B, such as building confidence and taking more chances to talk to girls.

Unhappiness Is Selfish

If your friend still isn't listening to your advice, turn the tables and discuss the ugly side of unhappiness. For example, those who are not happy are less likely to help others, more likely to put others in a bad mood, and generally take more than they give, says Raj Raghunathan, business professor and associate editor at the "Journal of Consumer Psychology." Viewed from this perspective, being happy is actually a generous and compassionate alternative, while being unhappy is selfish and demanding.

Say It Again

People who are feeling very down may need to hear your advice on more than one occasion, according to the National Institute of Mental Health article "10 Ways to Help Someone Who's Depressed" on Psych Central. For those who are very despondent, it can be hard to hear that they "deserve to be happy," and they may balk at those words at first. Be consistent, and keep sending the message that happiness is an option. Tell her that you care and that people love her -- and are rooting for her to pull through and feel happy again.