I prefer vipassana meditation and cognitive therapy and they do wonders. Though the goal is positivity but with a large dose of equanimity to keep it real. Science is learning more and more about the meditative brain and a recent study pretty much somes it up this way.
The normal brain is narrative based (internal talk) and beliefs create emotions. If you have negative beliefs or positive beliefs they create emotional effects you can feel in your body. When you stay in the present moment with enough meditative practice (thousands of hours day after day) you can experience a new base which is the present moment. People (and animals) when they are in the present moment tolerate circumstances better than when they cycle in negative rumination (one of the causes of depression).
Jhanas in the Hindu tradition allow you to focus on one object until your talking mind naturally rests. When that natural rest of internal talk happens the brain gets huge relief in the form of bliss, equanimity, and rapture. Unfortunately when you get out of the mediation, if you don't apply it to daily life, you go back to the same habits as before though a nice jhana can influence the rest of your day despite fading. With vipassana you try and create patience with any object (senses, internal talk, body sensations) so you can carry that into your daily life. Here noting and labeling with your awareness consistently can help with acceptance with what you can't change. Noting once per second is good enough for most people, but to achieve the high level equanimity of monks you have to meditate at 20Hz (20 times per second) to eventually over the years achieve what is called classical enlightenment. At that speed you go through the equivalent of neurosurgery where you try to attain a new present moment baseline. All meditators who go through this say it can be quite unpleasant because you have to be psychologically present for all your mind including negative personal aspects that everyone has. They are all happy to get though it (the dark night it's often called) but that dark night can encompass a number of years with some mental disfunction where fear, misery and disgust with existence can actually pop up when you least expect it. Of course the only way to get through this is the same prescence and acceptance of phenomena that got you there in the first place.
More on that here:
Dan Ingram Talk at Cheetah House 1/3 on Vimeo
Here are some good videos that can explain the method for those who are interested.
Beginners meditation:
http://www.youtube.com/watch?v=AY0Qt-8LXJE
Examples of simplified mental noting categories:
http://www.youtube.com/watch?v=Skl5LE7Uucg&feature=channel_video_title
In cognitive therapy you develop patience by using logic and to look at your internal schemas and beliefs and test them with logic and reality to see if they make sense. If they don't then that evidence can (when the method is repeatedly used), create new healthy beliefs that have their own feeling tone that is much healthier. If you have a belief that every food craving must be satisfied you will get fat. If you test your schema to logic (that you can survive cravings by tolerating them with patience and mindfulness) you can create a new psychological relationship to food. This requires lots of work and repetition when old habits takeover. Willpower is like a muscle in that it can wear out but it also can grow with practice so you HAVE TO train willpower to adjust habits.
I've talked to a psychologist I met at a restaurant about this stuff and he says a mixture of mindfulness (vipassana) meditation and cognitive therapy is best and that doing this is the equivalent of medication. So these practices really rewire your brain.
For monothestic cultures a more simple way is to play with beliefs. If you have a strong belief in Jesus Christ and you believe in the afterlife and you believe this in a very real way you can create a sense of equanimity very quickly without much meditation (because if nobody loves you then at least Jesus does). Though this is emotional and any proof that disproves religions can undermine faith and then the person may have to find some other way to cope with life's challenges like with what I posted above. The Christians have a meditative path as well (The Dark night of the soul) which is similar to the Buddhist vipassana path so one doesn't have to abandon Christianity or any other faith if they apply cognitive therapy and mindfulness prescence for daily activity.
So the lesson is to not ruminate and apply prescence to life and test your opinions to logic when negative habitual ruminations appear.
http://www.youtube.com/watch?v=8zW8cDNboog
There's also some new areas regarding Positive Psychology which looks at not just making you feel less insane but to actually optimize and flourish.
http://www.youtube.com/watch?v=9FBxfd7DL3E