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Major Depressive Disorder

Involves dysregulation of serotonin, norepinephrine, and dopamine systems. Reduced hippocampal volume and prefrontal cortex activity.

Depression neuroimaging

© Blausen · CC-BY

Major depressive disorder affects over 280 million people worldwide and is characterized by persistent low mood, anhedonia, and neurovegetative symptoms. Neuroimaging reveals reduced hippocampal volume, hyperactive default mode network, and blunted prefrontal regulation of the amygdala. The monoamine hypothesis guided antidepressant development, but modern frameworks emphasize neuroplasticity, inflammation, and gut-brain axis contributions. Ketamine and TMS represent rapid-acting interventions targeting glutamatergic circuits.

Symptoms

Persistent sadnessLoss of interestSleep disturbancesFatigueDifficulty concentratingSuicidal thoughts

Neurology

Involves dysregulation of serotonin, norepinephrine, and dopamine systems. Reduced hippocampal volume and prefrontal cortex activity.

Treatments

SSRIs/SNRIsCBTECTKetamine therapyTMSLifestyle interventions

Gallery

Brain regions in depression

Brain regions in depression

Hippocampal atrophy

Hippocampal atrophy

Limbic system

Videos

2-Minute Neuroscience: Depression

Neuroscientifically Challenged

Serotonin & Depression

Huberman Lab

Related in NeuroSphere

serotoninhippocampusprefrontal cortexemotion

Explore Further

BrainFacts — Depression

via BrainFacts.org

Riisfeldt — Mood Disorders

via Riisfeldt Neurology Education

NeuroWiki — Major_depressive_disorder

via NeuroWiki

AAN — Depression Resources

via AAN Medical Student Resources

Kessler et al. — Global burden of depression

via PubMed

Lancet Neurology — Depression treatment reviews

via The Lancet Neurology

Sources & Attribution

BrainFacts.org Riisfeldt Neurology Education PubMed