Antidepressants increase the risk of suicidal thinking and behavior in children, adolescents, and young adults (18-24 years of age) with major depressive disorder and other psychiatric disorders. May worsen psychosis, or precipitate a shift to mania or hypomania in bipolar disorder. May cause CNS stimulation (restlessness, anxiety, insomnia) or anorexia. May cause motor or cognitive impairment. The risk of seizures is dose-dependent and increased in history of seizures, anorexia/bulimia, head trauma, CNS tumor, severe hepatic cirrhosis, abrupt discontinuation of sedative-hypnotics or ethanol, medications which lower seizure threshold (antipsychotics, antidepressants, theophyllines, systemic steroids), stimulants, or hypoglycemic agents. May increase the risks associated with electroconvulsive therapy. Delayed hypersensitivity reactions resembling serum sickness reported. May cause weight loss. Use with caution in cardiovascular disease, history of hypertension, or coronary artery disease. Caution in hepatic/renal impairment. Use with caution in the elderly (risk of accumulation during chronic dosing). Do not discontinue abruptly in patients receiving high doses chronically (withdrawal symptoms may occur). In patients being treated with bupropion for nicotine dependence, consider that depressed mood may be a symptom of nicotine withdrawal. Anaphylactoid reactions reported. Possible arthralgia, myalgia, and fever with rash and other symptoms suggestive of delayed hypersensitivity. Smoking may induce enzymes and increase metabolism of some drugs (cessation of smoking, with or without use of bupropion, may decrease enzyme induction and alter metabolism of some drugs, such as theophylline or warfarin).