As a class, unipolar depressive disorders are some of the most prevalent and vexing of all psychiatric conditions. They produce personal, social, and economic disruption for patients and pose significant challenges for service providers. Depression is a syndrome characterized by a number of behavioral, cognitive and emotional features and is most commonly associated with a sad or depressed mood, a reduced capacity to feel pleasure, hopelessness, loss of energy, maladaptive sleep patterns, weight fluctuations, difficulty concentrating, and suicidal ideation (APA 2000). Depression has been ranked as the fourth leading cause of disability worldwide and is expected to rise to second by 2020 (Murray 1997). Not surprisingly, depression is the most common psychiatric problem in primary care (Goldberg 1992).
Treatment for depression is predominately psychological and pharmacological. A range of medications have been studied to treat depression. Tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) were first introduced as treatments for depression in the 1950's and 1960's. Both types of antidepressants increased the availability of serotonin and norepinephrine in the nervous system. Since then, other agents influencing serotonin have been introduced. For many providers the selective serotonin reuptake inhibitors (SSRIs) have become first line agents for the treatment of depression. Although the SSRIs are slightly less likely than TCAs to cause side effects that could cause treatment discontinuation (Anderson 1996; Barbui 2000), they are associated with sexual dysfunction in as many as 67% of patients in clinical trials (Montejo-Gonzalez 97). Given that at least 30% of outpatients treated for depression are believed to be non compliant with treatment (NIH 1984) and that one of the major causes of treatment non response is noncompliance (Pampallona 2002), it is important to gather data on medicines that have tolerability profiles that encourage compliance.
Bupropion hydrochloride sustained release (bupropion), a unique aminoketone antidepressant, is thought to be an inhibitor of the neuronal uptake of norepinephrine and dopamine and has no known action on serotonin (Stahl 2005). Bupropion has been shown to be a well tolerated and effective treatment for depression (Feigner 1996; Lineberry 1990) and has been associated with a milder side effect profile in comparison to other antidepressants (Mann 2005). In addition, bupropion has not been associated with sexual dysfunction (Clayton 2005; Croft 1999;Feigner 1996) and has been used to treat sexual dysfunction associated with the use of SSRIs (Ashton 1998). Common side effects include headache, dry mouth, insomnia, and nausea (Settle 1998).
Despite the reports of efficacy and tolerability, evidence of any advantage of bupropion over MAOIs, TCAs, or SSRIs in the treatment of depression has not been established. This review aims to summarize the current research regarding efficacy and tolerability of bupropion in comparison to other antidepressants. This information should assist patients and their providers in making the best treatment decisions
(1) Primary objective: To determine the efficacy of bupropion in alleviating acute depressive symptoms compared to placebo and other antidepressant treatments.
(2) Secondary objective: To investigate the adverse effects of bupropion treatment including general prevalence of side effects.