A bit about neuroplasticity. What neuroplasticity means for a person has been captured nicely by Gandhi.
“Your beliefs become your thoughts,
Your thoughts become your words,
Your words become your actions,
Your actions become your habits,
Your habits become your values,
Your values become your destiny.”
For people who suffer from anxiety and/or depression, their mind is like a bad neighborhood or a torture chamber. On a neurological level, both modes have been associated with an overactive default-mode-network (DMN). The DMN is active when you're not engaging in a task, when you're "selfing". Recent studies on psychedelics suggest that the DMN is the neurological equivalent of the ego. Psychedelics suppress it, which can result in a change in identification from the ego to awareness. An expansive sense of self, up to the point of being one with nature, the universe or God. The level of mystical experience during a trip has been teased out as the most important variable for a positive outcome with regards to a variety of what we call mental illnesses. There is much overlap with meditation. Meditation is the practice of identification with the witness, of expanding your sense of self and creating space between experience and action. A bit narrow, but alright for this topic.
I mention meditation because the Gandhi quote isn't workable if you identify with your thoughts. If the trance of identification with the ego is complete. A certain level of mindfulness is necessary. Becoming aware is half the challenge. Whenever I catch myself wandering down the bad neighborhood, I remind myself that this is a thought, not reality. In the case of difficult emotions, they are just that. My mind's chatter on top of that is not helpful. Buddha is supposed to have said that the first arrow is the pain thrown by life, and the second arrow is you fighting what is. This is the difference between pain and suffering. One is inevitable, the other is habitual.
You could also say that scripts get activated in our brain and those scripts can be up- or down regulated. We get locked in grooves that are deep. When you are mindful of what happens, you can pick up the needle and start a more constructive groove. It'll deepen over time. We are creatures of habit, which can be used in your favor. Forming positive habits and interrupting your DMN with usefull stuff works very well for me. I just stop feeding the monster whenever I become aware that I'm doing so. Neurons that fire together, wire together. So whatever you feed gets up regulated when you do it on a consistent basis. That's why the number of depressions you had is a predictor for the risk of getting another one. Thick cables, deep grooves. Not destiny though. That's why neuroplasticity is awesome. Neurologically this is literally rewiring the brain. The brain that changes itself. Certain things can increase neuroplasticity. Psychedelics, exercise, certain supplements. I throw everything at, probably resulting in a synergistic effect.
I practice meditation daily and I've been binge listening to constructive podcasts and audio books for a couple of years. I started at rock bottom, now my life has gotten much better than ever. Combined with psychedelics and some other stuff, I've found this to be very successful. I refrain from recommending psychedelics, but I do think something in the vein of the other things I described is essential if you want to avoid ending up in that torture chamber for the rest of your days. Not saying this is the whole story, yet vital.