A 41-year-old woman is diagnosed with a major depression after a few weeks of having been operated of a stomach reduction (bariatric surgery). She goes into old antidepressant medication for a few weeks with an increasing worsening of her state, at the point she is sent to the emergency room with high irritability, intense agitation, suicide thoughts as the highlight symptoms of what we think to be a mixed episode of a bipolar disorder and how we orient the case during hospitalization. The patient follows both public and private psychiatric services and after discharge from acute hospitalization, still with residual depressions symptoms, her private psychiatrist substitutes the given treatment, including mood stabilizers, by only antidepressants. Two weeks after discharge from the hospital, the patient is relocated to our partial hospitalization resource. During her stay in our resource, we decide to keep the new treatment and diagnosis and increase the dosage of one of the antidepressants, which immediately yields to hypomania symptoms, at what we conclude that our patient is better treated as a bipolar type II with a mood stabilizer and low doses of an SRI. We find this to be an interesting case in the both psychopathological and psychophysiological point of view. To understand the case beyond clinical diagnosis, we discuss profoundly whether the bariatric surgery may have a role as a trigger.