Depression

At least one symptom in category 1 = persistent depressed mood and/or pervasive anhedonia

and four+ of category 2 = e.g. difficulty concentrating

Types-> unipolar, bipolar, post-partum, dysthymia + SAD

Mz Twins 69% cc & Dz Twins 13% cc

• MAOIs inbihit MAO, an enzyme that breaks down excess monoamines in terminal buttons. However can lead to excess monoamines
• Tricyclic antidepressants (antihistamines) show improvements in endogenous depression and encourages reuptake of 5-HT and NE to make the neurotransmitters active longer
• SSRIs inhibit serotonin reuptake
• ECT used as a treatment when epilepsy patients found reduced depression symptoms after a seizure
• Sleep deprivation sometimes effective

• Monoamine hypothesis = insufficient activity of monoaminergic neurones - depression caused by monoamines antagonist
• 5-hydroxyindoleactic acid = metabolite of 5-HT and suicidal depression is linked to low levels of this
• Tryptophan depletion = used to make 5-HT and low tryptophan diets caused relapse even when participants were medicated. PET imaging show reduced activity due to tryptophan depletion especially in pf cortex
• Drugs that increase release of 5-HT can temporarily inhibit activity of 5-HT neurones in brain but gradually become less sensitive (explanation for delay in drugs)