Epidemiology

Major depressive disorder

• 12% men
• 20% women
• with the right treatment, 70-80% of patients can improve their Sx

Pathophysiology

Reduction in 5HT (produced in raphe nuclei) and NA (produced in Locus coeruleus and lateral tegmental area) lead to Sx

Neurogenesis in depression: Depression is associated with increased dendritic arborisation = less neuronal connections able to form

Types

• post partum depression
• Atypical depression - have mood reactivity so pleasurable events improve mood
• melancholic depression - no mood reactivity
• Dythymia - mild Sx of depression that happen over a longer period of time

Risk factors:

• female
• past history of depression
• significant physical illness