Changes in Brain Function of Depressed Subjects During Treatment With Placebo

• Published in: The American journal of psychiatry Vol. 159; no. 1; pp. 122 - 129
• Main Authors: Leuchter, Andrew F., Cook, Ian A., Witte, Elise A., Morgan, Melinda, Abrams, Michelle
• Format: Journal Article
• Language: English
• Published: Washington, DC American Psychiatric Publishing 01.01.2002; American Psychiatric Association
• Subjects: Adult; Adult and adolescent clinical studies; Antidepressants; Biological and medical sciences; Brain; Cerebral Cortex - drug effects; Cerebral Cortex - physiopathology; Comparative studies; Cyclohexanols - adverse effects; Cyclohexanols - therapeutic use; Depression; Depressive Disorder, Major - drug therapy; Depressive Disorder, Major - physiopathology; Depressive Disorder, Major - psychology; Double-Blind Method; Electroencephalography - drug effects; Female; Fluoxetine - adverse effects; Fluoxetine - therapeutic use; Functioning; Humans; Male; Medical sciences; Mental depression; Middle Aged; Mood disorders; Neurology; Neuropharmacology; Pharmacology. Drug treatments; Placebo Effect; Placebos; Psychoanaleptics: cns stimulant, antidepressant agent, nootropic agent, mood stabilizer..., (alzheimer disease); Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Psychopharmacology; Venlafaxine Hydrochloride; Psychotropic; Central nervous system; Electroencephalography; Reuptake inhibitor; Electrodiagnosis; Antidepressant agent; Venlafaxine; Laterality; Mechanism of action; Mood disorder; Human; Hemispheric specialization; Serotonin; Fluoxetine; Treatment efficiency; Prediction; Depression; Chemotherapy; Treatment; Follow up study; Placebo; Norepinephrine; Hemodynamics; Comparative study; Brain (vertebrata)
• ISSN: 0002-953X; 1535-7228
• DOI: 10.1176/appi.ajp.159.1.122

OBJECTIVE: It has been proposed that 50%-75% of the efficacy of antidepressant medication represents the placebo effect, since many depressed patients improve when treated with either medication or placebo. This study examined brain function in depressed subjects receiving either active medication or placebo and sought to determine whether quantitative electroencephalography (QEEG) could detect differences in brain function between medication and placebo responders. Both QEEG power and cordance, a new measure that reflects cerebral perfusion and is sensitive to the effect of antidepressant medication, were examined. METHOD: Fifty-one subjects with major depression were enrolled in one of two independent, 9-week double-blind, placebo-controlled studies in which either fluoxetine (N=24) or venlafaxine (N=27) was the active medication. Serial QEEG recordings were performed during the course of treatment. After 9 weeks, the blind was broken and subjects were classified as medication responders, placebo responders, medication nonresponders, or placebo nonresponders. RESULTS: No significant pretreatment differences in clinical or QEEG measures were found among the four outcome groups. Placebo responders, however, showed a significant increase in prefrontal cordance starting early in treatment that was not seen in medication responders (who showed decreased cordance) or in medication nonresponders or placebo nonresponders (who showed no significant change). There was no significant change in QEEG power during treatment. CONCLUSIONS: These findings suggest that "effective" placebo treatment induces changes in brain function that are distinct from those associated with antidepressant medication. If these results are confirmed, cordance may be useful for differentiating between medication and placebo responders.