symptoms are probably related to tramadol's effect on serotonin and norepinephrine re-uptake. Symptoms may include those of  SSRI discontinuation syndrome , such as anxiety ,  depression , anguish, severe mood swings, aggressiveness, brain "zaps", electric-shock-like sensations throughout the body,  paresthesias ,  sweating , palpitations ,  restless legs syndrome , sneezing,  insomnia