About 5 years ago, a 45-year-old patient without personal or familial history of psychiatric disorders started to work in a lamp factory, where he handled inorganic mercury. Some 6 months after daily contact with the metal, he started to present with gingival hemorrhage, headache, tremors of the extremities, loss of the recent memory, insomnia, and severe depression (lack of pleasure, social withdrawal, psychomotor retardation, depressive mood, feelings of worthlessness and inappropriate guilt, irritability). Even exhibiting such a condition, the patient continued to perform the same function for 1 more year. In this way, his symptoms became more intense. After a high metal dosing in his urine (only at that moment he was submitted to this exam), 105 mg/L (nl: 25mg /L), the patient was dismissed from work. Subsequent to withdrawal from exposure, the physical symptoms disappeared; however, the neuropsychiatric symptoms continued. For 3 years, the patient remained without medical care, and he was then referred to our outpatient unit. At that time, the patient did not show detectable levels of mercury in his urine. As the patient exhibited significant depressive symptoms, he was administered sertraline. While his changes of mood improved, the dose of antidepressant was increased until it reached 250 mg/day. With this dose, the patient no longer presented with depression; however, recent memory impairment and the insomnia persisted.