That is very very weird because I was always told that tramadols had slight SSRI effects but when I looked it up I didt get anything on it. Tramadol is a quasi-narcotic analgesic used in the treatment of moderate to severe pain. It is a synthetic analog of codeine, but has a low binding affinity to the mu-opioid receptors. It has been prescribed off-label for the treatment of diabetic neuropathy and restless leg syndrome.
tramadol does increase serotonin levels. Here is one reference. . . but there are plenty: http://opioids.com/tramadol/prescribe.html