Chronic Sadness

I often wonder what is going on in the heads of those with chronic sadness, or at least those who can't seem to shake off the feeling of being depressed and unmotivated to doing anything. Is it a nagging sensation that nothing is worthwhile, that nothing can be done? I wish I could reach into the person's head and just shake out that nasty thought of an inability to do something about their situation. No wise words here. Just a desire to change a situation. Only God can do it ultimately, and maybe that's worth a reminder to the person.