Apparently, Happiness = P + (5xE) + (3xH). Although in some ways rather silly, this BBC report on a mathematical model for happiness follows a human givens perspective by trying to quantify the extent to which someone's basic needs are met and the level of their innate abilities. You can find it here.
Your body needs certain vitamins, minerals, proteins, fats, and carbohydrates in order to keep itself healthy. The same goes for your mind. When these needs are not being met, people become vulnerable to emotional problems such as depression or anxiety. When they are fulfilled and someone is properly emotionally nourished, their problems become more manageable and they can escape from being trapped in them.
It sounds obvious, really, so why is it so often a problem? The reason is that, like nutrition, effects do not show through immediately. After all, you could eat chips every night for quite a while without suffering any immediate problems. If, however, there was a cold or virus going around, you would be more likely to catch it and it would hit you harder than if you had been eating well. Similarly, if your emotional needs are not being met your 'emotional immune system' is less able to cope when something bad happens and you be laid low by something you would otherwise have coped with.
So if you are suffering from a problem, the first thing to look at is to check you are meeting your basic needs.
They are:
Human beings are genetically disposed to being sociable and giving and receiving attention and affection. Just look at the amount of time our nearest relatives, chimpanzees, spend grooming each other!
Other people also help keep our perceptions of the world on the right track. Ever wondered why the crazy witch in fairy tales always lives on her own in the middle of a forest or somewhere else away from everybody else? Other people unconsciously guide us toward a balanced and healthy view of the world.
The isolating pressures of modern society -- people living on their own, working at home, and communicating over the Internet -- remove many of the obvious sources of attention and interaction so people have to actively create their own through friends, family, clubs, community groups, or even pets!