how this can be prevented?
Eating large amounts of fish, Behavioral interventions, such as interpersonal therapy and cognitive-behavioral therapy
Major depressive disorder
Eating large amounts of fish may also reduce the risk.

Behavioral interventions, such as interpersonal therapy and cognitive-behavioral therapy, are effective at preventing new onset depression.
what does single episode major depressive disorder mean UNANSWERABLE what are symptoms of  this disorder? Low mood, symptoms of psychosis; like delusions and hallucinations are some of them how it is caused? Childhood abuse, either physical, sexual or psychological are all risk factors
wiki:1591183
Major depressive disorder [SEP] Screening and prevention
Since 2016, the United States Preventive Services Task Force (USPSTF) has recommended screening for depression among those over the age 12; a 2005 Cochrane review found that the routine use of screening questionnaires has little effect on detection or treatment. Preventive efforts may result in decreases in rates of the condition of between 22 and 38%. Eating large amounts of fish may also reduce the risk. Behavioral interventions, such as interpersonal therapy and cognitive-behavioral therapy, are effective at preventing new onset depression. Because such interventions appear to be most effective when delivered to individuals or small groups, it has been suggested that they may be able to reach their large target audience most efficiently through the Internet.