The release of the adrenal-based hormone cortisol is behaviour-related. Therefore the only relevant 'control' is behaviour-based. To manage stress and the subsequent flood of cortisol we must alter how we react to stimulus-- we need to re-train our brains. Acceptance and Commitment Therapy and Mindfulness are strategies to re-train the mind.
ACT and Mindfulness represent the most 'natural' management system we can infuse into our minds-- it is literally mind-altering in a physical sense: it will change your brain via the physically malleable nature of your brain that is neuro-plasticity. You will become a different person, able to react in different ways than you would have just months before. How valuable would it be for your road rage to disappear? How would your self-respect blossom if that manipulative friend or relative could no longer control your behaviour, and leave you hating yourself at the end of the day?
Much of our anxiety and depression arises from cognitive dissonance-- behaving contrary to what you believe. We do this all the time, and it's this chaotic and contradictory behaviour that's killing our joy. We fall into those self-destructive mind states automatically because that's how we were trained. You can train your body to perform many remarkable feats, and it becomes the default state to play that piece of music perfectly, sink that basket every time, and remove that brain tumour with perfect precision! Training enables these behaviours.
You can re-train your brain too, and make it react naturally in ways that don't contradict your convictions.
Many of us take the antidepressant for a couple of years and effectively go to sleep, emotions buried-- a well-deserved rest. At some point we wean off. After 6 months our anxiety and depression creeps back in, and we still can't recognize that nothing's changed-- our same old brain with its same old behaviours and default mind states is right there waiting for us-- right there waiting to sabotage our happiness once again!