Depression is an illness that may affect as many as 10% of adults. In addition to abnormal functioning of the brain, depression is also thought to result from an imbalance of chemicals in the brain. An article published in the January 6, 2010 issue of the Journal of the American Medical Association (JAMA) states that antidepressant medication can be very effective in patients diagnosed with severe depression, however, these same drugs are not very effective in patients diagnosed with less severe depression. In summarizing the data, doctoral candidate and author, Jay Fournier, stated that the medications administered to patients who were considered to be on low- and middle-range of severity for depression were not doing much beyond the effects produced by placebos.
This new study implemented a technique called meta-analysis where the data from numerous studies were complied and, based on a set of criteria, specific studies were either included or excluded from the analysis. For example, two criteria of this study were: (1) data for 6+ weeks was available, and (2) the Hamilton Depression Rating Scale (HDRS) was employed to measure depression severity. Data from six studies (718 subjects), that was completed over the last 20 years, was included in the analysis.
Of these six studies, three studies used the drug paroxetine (a selective serotonin reuptake inhibitor) while the other three studies used the drug imipramine (tricyclic antidepressant). While the authors note certain limitations of their study (only a small proportion of the subjects included in the studies had scored low on the HDRS, a measure of depression severity), the data highlights an important consideration: Are the doctors that prescribe these drugs to patients with low- to-moderate depression aware whether the studies upon which the effectiveness of these drug are based, and that they included patients who do not have severe depression?