Wellbutrin XL for Dysthymic Disorder

Inclusion Criteria: * Male and female outpatients 18-65 years of age. * Patients with a Diagnostic and Statistical Manual Fourth Edition (DSM-IV) diagnosis of dysthymic disorder, early onset. * Patients will have a total score of 12 or higher on the Hamilton Depression Scale (24 items) at baseline. Exclusion Criteria: * Patients with a DSM-IV diagnosis of Delirium, Dementia, and Amnestic, and other Cognitive Disorders. * Patients who are pregnant or nursing women. * Patients with a principal diagnosis meeting DSM-IV criteria for: Major Depressive disorder, Bipolar Disorder or cyclothymia, Schizophrenia, Delusional (Paranoid) Disorders and Psychotic Disorders not elsewhere classified, Severe Borderline Personality Disorder * Patients who have a current or prior diagnosis of Anorexia Nervosa or Bulimia * Patients who, within the past 6 months, met DSM-IV criteria for abuse of or dependence on any drug, including alcohol. * Patients who would pose a serious risk for suicide during the course of the study, as evidenced by one of the following: * Report of having a specific plan for killing themselves, * A score of 3 or higher on the Hamilton Depression Rating Scale item #3 as rated by the treating clinician at Week 0, (indicative of active suicidal thoughts or behaviors), or * A suicide attempt within the past 12 months requiring emergency room visit, medical or psychiatric hospitalization, or otherwise deemed to be life-threatening (e.g. an overdose of \> 1 week's dose of medication). * Patients with a history of recurrent Grand Mal seizures or at risk of Grand Mal seizures, and those with other medical conditions in which Wellbutrin XL would be contraindicated, including a history of head trauma. * Use of any psychotropic medication within 1 week of starting study medication * Use of a monoamine oxidase inhibitor (a type of antidepressant) (MAOI) within the 14 days prior to the initial dose of study medication. * Use of fluoxetine within 28 days of the initial dose of study medication. * Use of Zyban® or other forms of bupropion hydrochloride (i.e. Wellbutrin immediate release or Wellbutrin Sustained Release (SR)) within 2 weeks of the initial dose of medication. * Patients who have failed to respond to adequate trials (minimum of six consecutive weeks) of two different classes of antidepressant medication (see Table 1 for definitions of an adequate trial.) * Patients with unstable medical conditions, such as acute hyperthyroidism, uncorrected hypothyroidism, undiagnosed fever, uncontrolled angina, or any other serious medical illness, including any cardiovascular, hepatic, respiratory, hematological, endocrinologic or neurologic disease, or any clinically significant laboratory abnormality. * Patients who have begun a course of psychotherapy within 3 months of starting the study, or who plan to terminate an ongoing psychotherapy prior to the end of the study.