You've watched "Seinfeld" re-runs, splurged on yourself and downed pints of Ben and Jerry's. Nothing's helping. Maybe you're one of the 20 million Americans diagnosed with depression, you're bottoming out or you just want something to improve your day.

Here are five ways — some admittedly challenging — to help you get that much-needed mood boost: 
1. Pick good parents

In Happy Land, genes trump environmental factors, according to the experts. And a study in the March issue of the journal Psychological Science scores another point for the gene team: Differences in DNA that could explain why some people tend to have an extra bounce in their step might also underlie the tendency to be more emotionally stable and socially and physically active.

Genes do not provide free passes from the doldrums, and other external factors will still try to mow you down. But, heredity could provide some people with a horde of happiness that they can draw from when the good times aren’t rolling.

And Canadian researchers' ability to genetically stifle depression in mice in 2006 indicates that human happiness could one day be improved by manipulating genes. This was the first time science throttled the throes of any organism. Mice bred to be void of the gene, called TREK-1, acted as if they had been downing anti-depressants for at least three weeks.

2. Give it away

It only takes $5 spent on others to make you happier on a given day, according to a 2008 study. And selfless acts can also help your marriage become a more enjoyable experience for you and your spouse.

After performing good deeds, people are happier and feel their life has more purpose. But is the act selfless if you expect something in return? Maybe it just depends on how you look at it.

3. Ponder this

Think of a happy place. And you, too, like Happy Gilmore, might sink that putt and earn back your grandmother's house — or overcome your own hurdle.

Humans are more resilient than we think and can endure trying times, as demonstrated in a 2005 study that tracked mood changes in dialysis patients. They were in a good mood most of the time despite having their blood cleaned three times a week for at least three months. But healthy patients envisioned a miserable life when asked to imagine adhering to this demanding schedule.

As Winston Churchill said, "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."

4. Work out

Consistently breaking a sweat, along with medication and counseling can help people battling depression by sapping lonely and vulnerable feelings.

Exercise improves one's state of mind in part by affecting the body's levels of two chemicals: cortisol and endorphins. The adrenal glands of angry or scared people produce cortisol. This increases blood pressure and blood sugar, weakens the immune response and can lead to organ inflammation and damage. But working out burns cortisol, restoring the body's normal levels.

Running, biking or using an aerobic exercise machine also causes the brain to release endorphins — the body's natural pain relievers — into the bloodstream. The body foregoes the negative side effects of drugs while still experiencing a natural high. To gain the most from your workout, make sure its intensity reflects your stress level. And challenge your body to continually adapt by varying the exercise’s length and intensity.

5. Live long

If you have the right genes and are selfless, optimistic and active but still find yourself down in the dumps, just give it some time.

A study of 2 million people from 80 nations released in January found that depression is most common among adults in their mid-40s. Among Americans, the worst of times hit women around age 40 and men about age 50.

But with age humans are more inclined to filter out the negatives while focusing on what they enjoy.

Americans in their golden years tend to see the glass as half full, despite their increased doctor visits and chemo treatments. After battling cancer, heart disease, diabetes or other health-related obstacles, 500 independent Americans from age 60 to 98 rated their own degree of successful aging as 8.4 on average, with 10 being the highest in a 2005 study.

Happiness, it seems, takes time.