Recovering Evidence from SSD Drives: TRIM, Garbage Collection, Exclusions (2014)

I guess that this boils down to "always use full-disk encryption". Just remember to benchmark your CPU to make sure you're using hardware-accelerated AES or you're going to lose a lot of performance from this SSD...

TRIM is not meant to be a security feature. It is optimized for reducing write amplification and improving performance. It could have been implemented to be more secure while trading off on performance.

Quoted from the article:

More SSD drives appear to follow the Deterministic Read After Trim (DRAT) approach defined in the SATA standard a long time ago. This in turn means that a quick format is likely to instantly render deleted evidence inaccessible to standard read operations, even if the drive is acquired with a forensic write-blocking imaging hardware immediately after.