Right hemisphere abnormalities in major depression: quantitative electroencephalographic findings before and after treatment

J Affect Disord. 1996 Oct 14;40(3):169-73. doi: 10.1016/0165-0327(96)00057-2.


The quantitative EEGs of drug-free depressed patients were analyzed and compared to age and sex-matched controls, using spectral analysis. In addition, QEEGs of depressed patients after clinical improvement resulting from 6 weeks of antidepressant treatment were also analyzed. The subjects were 20 patients suffering from major depression (DSM-III-R). Scores on the Hamilton Rating Scale for Depression (HRSD) of all patients showed a reduction of more than 50% at the end of the 6th week. The results show: (1) delta and theta bipolar absolute powers of the right hemisphere increased in drug-free depressed patients, compared to controls. (2) No changes in all bands of QEEG were found after clinical improvement resulting from 6 weeks of treatment. These results suggest that the right hemisphere plays an important role in major depression, and that a reduction in symptoms is not necessarily indicative of an improvement in underlying major depression.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amitriptyline / adverse effects
  • Amitriptyline / therapeutic use*
  • Antidepressive Agents, Second-Generation / adverse effects
  • Antidepressive Agents, Second-Generation / therapeutic use*
  • Antidepressive Agents, Tricyclic / adverse effects
  • Antidepressive Agents, Tricyclic / therapeutic use*
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / physiopathology
  • Depressive Disorder / drug therapy*
  • Depressive Disorder / physiopathology
  • Depressive Disorder / psychology
  • Dominance, Cerebral / drug effects*
  • Dominance, Cerebral / physiology
  • Dose-Response Relationship, Drug
  • Electroencephalography / drug effects*
  • Female
  • Fluoxetine / adverse effects
  • Fluoxetine / therapeutic use
  • Fourier Analysis
  • Humans
  • Male
  • Middle Aged
  • Signal Processing, Computer-Assisted*
  • Treatment Outcome


  • Antidepressive Agents, Second-Generation
  • Antidepressive Agents, Tricyclic
  • Fluoxetine
  • Amitriptyline