With this and other numerous incidents - it has been my personal experience and seen it in other cases where people struggling with mental health start avoiding a longer/bigger project and procrastinate with small new projects. Going no contact because of mental effort + needing to confront the shame of missed messages that only grows the longer the pause has been. I don't see any reason to doubt the depression claims here and elsewhere.
HOWEVER
Until the person has learned how to manage their workload so things keep moving forward and communication stays on. Until they have a solution, not just the excuse, there's no point of trusting them with either your monetary support or just belief in these forums. Again, from personal experience - having free money coming in makes confronting your issues really hard since the environment is rewarding you even if you're doing nothing.