Treatment with SSRIs rather than placebo was associated with clinical improvement by the end of the first week of use .
CONCLUSIONS Treatment with SSRIs is associated with symptomatic improvement in depression by the end of the first week of use , and the improvement continues at a decreasing rate for at least 6 weeks
CONTEXT Selective serotonin reuptake inhibitors ( SSRIs ) are often described as having a delayed onset of effect in the treatment of depression .
However , some trials have reported clinical improvement as early as the first week of treatment .
OBJECTIVE To test the alternative hypotheses of delayed vs early onset of antidepressant action with SSRIs in patients with unipolar depression .
The safety and efficacy of paroxetine compared with placebo in a double-blind trial of depressed outpatients.
Considerable research shows that serotonin dysfunction is implicated in major depression .  Paroxetine is an investigational antidepressant that appears to act by selectively blocking neuronal serotonin uptake . Seventy-two out patients with moderate-to-severe major depression entered this 6-week , double-blind comparison of paroxetine and placebo . The results showed clear and significant superiority of paroxetine on all of the major outcome variables . These included physician-rated measures such as the Hamilton Rating Scale for Depression and its four factor scores , the Clinical Global Impressions scale , the Montgomery and Asberg Depression Rating Scale , and the Raskin Depression Scale . Results on these agreed well with patient-rated measures like the Hopkins Symptom Checklist and Patient Global Evaluation Scale .  Paroxetine was also very well tolerated . Nausea and constipation occurred significantly more often with paroxetine , but only 9 % of paroxetine patients dropped out of the study due either in whole or in part to an adverse effect . This compares to 8 % of the placebo patients who were discontinued for the same reason . This study suggests that paroxetine is a safe and effective medication for the treatment of major depression
Treatment with SSRIs rather than placebo was associated with clinical improvement by the end of the first week of use .
CONCLUSIONS Treatment with SSRIs is associated with symptomatic improvement in depression by the end of the first week of use , and the improvement continues at a decreasing rate for at least 6 weeks
CONTEXT Selective serotonin reuptake inhibitors ( SSRIs ) are often described as having a delayed onset of effect in the treatment of depression .
However , some trials have reported clinical improvement as early as the first week of treatment .
OBJECTIVE To test the alternative hypotheses of delayed vs early onset of antidepressant action with SSRIs in patients with unipolar depression .