[Gormo]

Absolutely. People make rational decisions to fulfill the motivations they actually have. But sometimes people, being complex creatures, have multiple conflicting motivations, where fulfilling one impedes another, which leads to psychological and emotional distress. So mental health does come into it, but as a matter of reconciling conflicting parts of ones own psyche, not as a matter of overcoming irrationality.

Or, to put it another way, the irrationality is a matter of having contradictory desires in the first place; choosing to act upon one and dismiss the other resolves the irrationality. The fact that some people make the trade-off in the opposite direction that you would doesn't make them irrational, it just demonstrates that people are different.