Necessary Adaptation?

We, as humans, By our very nature adapt to the environment we are in. All of God's Creation does this, it's Darwin's "Natural Selection". Those that Adapt survive, and those that don't die.

There are many ways Humans Adapt. We adapt Emotionally and spiritually just as much as we do Physically. In fact, many Personality disorders are just that, the mind's attempt at Adaptation. Trading something for a Short-term "coping skill" with Long-term Consequences, Like Multiple Personalities, or Clinical Depression.

So, how does one know when his/her adaptation is More harmful than helpful in the long-term?