To be 'jaded' = to lose the will to live
I believe it means they are not telling the complete truth
dulled by surfeit exhausted (Example: "The amoral, jaded, bored upper classes")
Someone (generally a Woman) who is Worn out, wearied, exhausted or lacking enthusiasm, due to age or experience. From "jade" a worn out horse
Someone is considered "jaded" when they think they have seen and done it all, and they act bored and unexcited at whatever is happening around them.
A person with a jaded heart believes there is no such thing as love. They will use others for their own pleasure not caring how it may hurt the person.