What makes human happy? What makes you happy? Is it the material and tangible things? Or is experiences or people? Happiness can be measured and defined in so many ways but according to a study by a team of researchers in London School of Economics, a person's happiness is based on their personal relationships as well as their physical and mental health.

According to Lord Richard Layard, the one who led the report, said that even if people have earned more than they need, they weren't really happy because economic factors are not really the cause of unhappiness.

The studies found that when depression and anxiety are reduced or eliminated, it would also reduce people's unhappiness by 20 percent compared to when poverty is reduce which only lessens a person's misery by just 5 percent.

The researchers also added that if mental illness is treated, it will be more effective in increasing people's happiness.

"Tackling depression and anxiety would be four times as effective as tackling poverty. It would also pay for itself," Layard said.

Even previous psychological and social researches suggest that a person's wellbeing has a more significant impact to his happiness compared to the income level.

"The evidence shows that the things that matter most for our happiness and for our misery are our social relationships and our mental and physical health," said Lord Layard. "This demands a new role for the state - not 'wealth creation' but 'wellbeing creation'."

He also added that an increase on income and education attainment only had a little effect on the overall happiness of a person. And that having partner or being with someone that matters to you can increase the feeling of satisfaction.

The researchers said that in order to have a happy adult life, the emotional and the mental health of the person will be the most significant determining factors.