Depressed? Skip the doc and head straight to the docks--as in your favorite dockside seafood restaurant.

If the maritime atmosphere doesn't lift your spirits, the menu sure will--because the omega-3s found in fatty fish like salmon and tuna are the ultimate blues busters.

And a new study finds that seniors in particular could have the most to gain.

Iranian researchers recruited 66 seniors and gave them either a placebo or an omega-3 fatty acid supplement that contained 300mg of both eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Six months later, and the catch of the day was a genuine mood boost: The Seniors who took the supplement did significantly better on a 15-question depression assessment, according to the study in the European Archives of Psychiatry & Clinical Neuroscience.

This wasn't a fluke, either--in fact, we've seen these results before.

Back in 2008, researchers put 1,000 mg of fish oil a day up against a standard 20 mg dose of fluoxetine, better known as Prozac.

And if more depression patients knew about the results of this one, maybe they'd finally cut the line on Prozac for good--because the researchers found the fish oil to be every bit as effective, with none of the drug's notorious side effects.

But you don't have to be depressed to start taking fish oil --other studies have found that a daily omega-3 supplement now will lower your risk of even coming down with the condition later.

Daily fish oil can also help your heart, brain, eyes, and gums, raise levels of HDL cholesterol, lower triglycerides and prevent blood clots.

Don't be left adrift on this one: If you're not getting enough omega-3 fatty acids from a diet rich in salmon, tuna, trout, herring and anchovies, make sure you add some fish oil capsules to your regimen.

You won't be alone--fish oil was the number one supplement last year.

It even beat out multivitamins, although it probably got a big assist from the fact that Big Pharma fish oil, Lovaza, did about $1 billion in business.

I've got mixed feelings on that: It shows Big Pharma that you can make money and help people by selling a natural supplement instead of risky drugs, and that can't be all bad... right?

On the other hand, it's badly overpriced--so unless you've got the world's best prescription drug plan, skip the Lovaza and stick to a high-quality fish oil supplement from a trusted brand.

You'll get all the benefits for a fraction of the price.

I'm not done with senior health yet--keep reading for some fun and easy ways to avoid physical and mental decline.