Researchers have found that people who eat a healthy amount of fish have a lower risk of depression, with men seemingly benefiting more than women.
An estimated 350 million people worldwide suffer from depression. In the U.S., more than 14.8 million people have the disorder.
Twenty-six studies involving more than 150,000 were reviewed by scientists to examine the relationship between a diet high in fish and depression.
“Studies we reviewed indicated that high fish consumption can reduce the incidence of depression, which may indicate a potential causal relationship between fish consumption and depression,” Fang Li, lead researcher of the study. 
The meta-analysis took place in China by investigators from the Dongfeng Zhang of Medical College of Qingdao University. The findings are published in the Journal of Epidemiology & Community Health. The authors wrote that more research is needed to determine whether the association between fish consumption and lower incidences of depression vary according to the type of fish.
Upon reviewing the data, researchers found a 17% overall decrease in depression risk among people who ate a lot of fish compared to people who didn’t. In men, specifically, there was a 20% decreased risk; in women, the risk was lowered by 16%.
Other studies have suggested a link between poor diet and depression. Another recent meta-analysis revealed that adhering to a healthy diet was associated with a lower risk of the disease. The research was unable to point to which types of foods – including fruits, veggies, and fish – for provided the biggest benefit. (Here are 4 foods that can fight depression.)
How eating fish drops the risk of developing depression isn’t clear, but scientists theorize that the omega-3 fatty acids in fish may somehow alter the structure of the brain’s cell membranes. Or, the researchers hypothesize, omega-3s can impact dopamine and serotonin levels, thereby lowering rates of depression.
It’s not the first time an association has been found between seafood – or, at least, some of its components – and a smaller risk of depression and other psychiatric disorders.
A 2007 Norwegian study of about 22,000 people found that those who took fish oil supplements were approximately 30% less likely to have the symptoms of depression than those who didn’t. And in May, scientists from Emory and Harvard universities discovered that inflammation may be a contributing cause of depression, and that when patients with inflammation took omega-3s, the oils effectively treated the disorder. 
But according to psychologist Paul Coleman, PsyD, it could just be that people who take better care of themselves are less likely to be depressed.
“It could be that people who eat more fish are health conscious and less likely to eat junk food,” he says. “Because they are health-conscious, it means they also take care of themselves in other ways — more exercise, clean living, etc., all of which can reduce the likelihood of depression.”
Coleman also says it may be that people who aren’t depressed simply eat more fish.
My thoughts? It’s definitely a worthy avenue worth exploring if you’re feeling down.
 Yahoo! Health
 Medical Daily