Objective: Brain imaging studies have shown that depressed individuals suffer from inadequate frontal lobe functions vis à vis smaller frontal lobes. The effects of depression's recurrent nature and long-term antidepressant treatment are not definitely known. This study aimed to examine frontal lobe volume at the onset of clinical depression by including first-episode drug-naive depressed patients.
Method: The study included 23 first-episode drug-free major depression patients diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) and 28 healthy age- and sex-matched controls. Cranial magnetic resonance (MR) images were obtained in both groups using a 1.5 Tesla device. Gray and white matter volumes in the frontal lobes were measured using the Medical Image Processing Analysis and Visualization (MIPAV) computer program.
Results: Frontal gray matter volume in the patients was lower than that in the control group. White matter and total intracranial volume did not differ between the 2 groups. Small gray matter volume was not correlated with the duration or severity of illness.
Conclusion: The results of this study indicate that frontal lobe gray matter volume is low in first-episode depressed patients and is independent of both illness severity and duration. This result suggests that the observed changes in the frontal lobe could have occurred before the clinical symptoms of depression were observed.