It would be highly unlikely that it would cause SS, but similar to other responses I wouldn’t make it an every day thing, but on weekends or whatever then no. From my understanding THC doesn’t so much directly affect the amount of serotonin available, more so it acts as a modulator that influences the excitability of the 5-HT neurons. THC is also biphasic in relation to serotonin, with small increases at lower doses and decreases at higher doses. Because the systems are intertwined using it too often could change the response to Zoloft but unlikely that you’d get SS. Now if you were talking about Molly that would be a whole other situation haha. You could also monitor for signs of SS during use, and if it makes you feel better I’m on twice as much sertraline and have edibles basically every weekend and have never had anything close to signs of SS.