Disclosed are methods of treating a patient having Major Depressive Disorder (MDD) or Treatment Resistant Depression (TRD). The methods include administering to the patient a therapeutically effective amount of bupropion hydrobromide in extended-release form. The methods are more therapeutically effective in treating MDD or TRD than administration of an equivalent plasma dose of bupropion hydrochloride in extended-release form. In addition or alternatively, the therapeutically effective amount of bupropion hydrobromide reduces the incidence of one or more adverse events (anxiety, agitation and/or insomnia), when compared to the administration of the equivalent plasma dose of bupropion hydrochloride in extended-release form.