not positive I followed...if you texted someone who you know is in a depression downturn, there is a high probability that they have been or will be isolating themselves. So I would reach out to the person on a regular basis depending how close the relationship is, you can call, stop in person, etc...

Sometimes I enjoy just having another person to watch a movie with...I might not say much but it is a comfort...

So what does regular basis mean...hmmm...not sure...if you have been down this road with the person before you may be in a position to use that history...I would think trying to get a response daily using a variety of ways would be good...