The depressive brain is structurally different compared to a non-depresssive brain. And it seems to run in the family. This is reported by scientists at Columbia University. Those with a family history of depression have brains which are, on average, 28% thinner in the area of the right cortex compared to those with out familial history of depression. This difference seems to be evident long before depressive symptoms, if ever, come up. The cortex is the outermost layer of the brain and this thinning of the cortex is also somewhat similar to those observed in patients with schizophrenia or Alzheimer’s disease.
According to Dr. Peter Bradley, lead researcher:
The greater the anatomical differences seen in patients, on average, the more severe were their symptoms of cognitive impairment. Subjects who showed cortical thinning in the left hemisphere of the brain went on to develop the hallmark symptoms of clinical depression or anxiety.
The most common symptom of depression is sadness. However, it goes far beyond than just feeling down or having the blues. Researchers have long identified that clinical depression comes with a wide range of neurological and cognitive problems including:
- Problems with concentration
- Problems with visual memory
- Failure to pick up on social and emotional stimuli
These symptoms cannot be attributed to emotional and psychological problems alone. The current study published in the Proceedings of the National Academy of Sciences, indicate that there is a physiological and anatomical side to depression.
The study looked at the brains of 131 people using functional magnetic resonance imaging (fMRI) technique. The study participants were aged 6 to 54 years old “who were biological descendants (children or grandchildren) of individuals identified as having either moderate to severe, recurrent, and functionally debilitating depression or as having no lifetime history of depression.” The cortical thinning was observed to correlate well with severity of depression and the symptoms listed above.
The findings suggest that the cognitive problems may not be due to depression but may actually be the cause of the depressive symptoms. The thinning of the right cortical region suggest that an individual is at risk of developing depressive symptoms. If the thinning spreads to the left cortex, the cognitive weakness can lead to full-blown depression.
“…the cortical thinning in the right hemisphere produces disturbances in arousal, attention, and memory for social stimuli, which in turn may increase the risk of developing depressive illness.” The findings may have some major implication in the screening for depression. When signs of right cortical thinning are detected early, certain therapies can be used to help patients compensate for their cognitive problems and thus minimize depressive symptoms.