This is a terrible conclusion from a terrible experiment. From what I understand, they set up a condition where a subject had low control over an outcome (light

This is a terrible conclusion from a terrible experiment. From what I understand, they set up a condition where a subject had low control over an outcome (light being turned on) and then asked them to assess how much control they actually had. Since the experiment was set up to provide low control, those with feelings of low control (depression) were more likely to be right. If the experiment was biased to provide a lot of control, the depressed would not be "realistic" - they would under-value how much control they actually have. Maybe I am misunderstanding the experiment but that's what I see. In reality, you have a TON of agency in your life where your attitude drives the outcome. Eg - if you are depressed and out of shape, you will believe "I can never get fit" so you won't bother getting off the couch and this your pessimistic prediction will come true. Meanwhile someone else can believe they can do this, get off the couch and start exercising. So they will then make their own prediction come true. In the end it's as the serenity prayer says: G-d, grant me the Serenity To accept the things I cannot change... Courage to change the things I can, And Wisdom to know the difference. Nihilism and depression are no more realistic than mindless optimism. But if you had to chose one, chose action because it can drive change