Can I deduct investment devaluation from dividends?

I'm sorry, but how is an investment devalued from dividends? Could you be more explicit?

Gain or loss is determined from the difference between the adjusted basis of the asset and the price at which it is sold or exchanged.

What I mean is, how can my investments show a dividend paid when they've lost value... Most of my investments are off about 40% over the last year. I don't understand why I would need to report dividends on my taxes when I've lost money.

Well the reason is that dividends are a different kind of income from capital gain or loss. As you see, there is even a special line on the tax return to report that income. It is irrelevant whether the company paying the dividend did well or poorly.

Moreover, you don't lose or make money on your stock until you actually sell it; that is called a "realized" gain or loss.

Thank you for your help with my questions... I appreciate it.