I have being on the hiring side too, and if I asked you about that gap and got an honest reply about depression, that would tell me a lot. 1. you have identified an issue and worked to resolve it. 2. you are aware of it and may see it "coming" early next time (if it comes again).
I have been burnt too many times from people misrepresenting themselves in interviews (not being real to themselves to "sell" themselves) that I really value open and honest people. I think they know themselves, better, therefore their weaknesses and strengths too.
Could you hit rock bottom if I hired you? Sure, but it wouldn't be a complete surprise, and we could work together to prevent it and make sure you have the help needed before things got bad. (As if I hired you, it was for your skills and drive and fit and I'd want you to stick around to continue that).
Employers and employees can work though a lot if we both are honest and both are bringing something to the party (a job someone wants and the skill/desire to learn/perform).
Note I do not work in the US, and this is my experience.
Answering honestly will either result in:
a) Your employer appreciates your honesty and hires you according to your skills. They will be considerate if you begin to relapse and help get you to a better place by familiarising themselves with the condition, or;
b) Your employer will discriminate you based on your mental illness (assuming your skills are not a factor). They will see it as a risk and be unwilling to help you and help manage your condition regardless of what you can contribute.
You do not want to work for company b), so consider them a dodged bullet. Although they aren't likely to disclose depression as a factor, you may be able to see it their reaction when you tell them. Subtle body language such as leaning back in their chair and looking away may indicate they have already made their decision.
If you were to answer dishonestly you will be at a greater risk of working for an apathetic employer. If you were to relapse you might find explaining your condition difficult and they may think you're disgruntled and let you go.
I don't work in the US either, I don't know how aware people are of mental health and how tolerant they are there. I like to assume people in the tech industry are very familiar. Speaking from experience I know a lot of developers (including myself) who suffer from depression from time to time and are empathetic to one another. Your potential employers should be very familiar already.
A hiring manager that is human, that can relate and empathize will be your ally. You're only going to connect with those people by engaging them honestly.
You might be surprised by the number of people that share a similar experience.
I personally would be honest about why you took the break including calling it what it is but framing it as managing stress and looking after yourself, and move on to how that terrible and isolating experience for you might actually increase your value as a co-worker. Eg, perhaps you now have better skills for managing stress, know exactly how much overtime you can handle, have a better idea of what sustainable pace you can work at, be willing to stand up against ridiculous deadlines that you know can't be met even if just for self preservation, will be more caring and compassionate and tolerant to co workers and perhaps recognise symptoms of burnout/depression in them before they do.
Best of luck, look after yourself!
Of course you could argue that such an inattentive employer is unlikely to be a good employer.