Combining SSRI antidepressants with aspirin or other NSAIDs can lead to a 42% increase risk for bleeding. SSRIs may inhibit the uptake and storage of serotonin by platelets. Low platelet serotonin leads to reduced platelet aggregation and a tendency to bleed.
Considering that SSRIs have little evidence that they work better than placebo and that they are associated with a myriad of side effects such as impotence, insomnia, osteoporosis, cardiac rhythm disturbances, and weight gain. One would think that MDs would begin using placebo as they'd get the same effects without the side effects.