What we need for mental health is not a tensionless state but a certain degree of tension between what one is and what one should become.
Book: Man's Search for Meaning
Mental health is based on a certain degree of tension, the tension between "what one has already achieved" and "what one still ought to accomplish". It is a dangerous misconception of mental hygiene to assume that what one needs is a tensionless state. We need existential dynamics in the gap between what one is and what one should become, instead of equilibrium or, as it is called in biology, "homeostasis".
What we need isn't the discharge of tension at any cost but the call of a potential meaning waiting to be fulfilled by us. Therefore, if therapists want to foster their patients' mental health, they should not be afraid to create a sound amount of tension through a reorientation toward the meaning of patients' lives.