Affective Disorders

Emotional States and The Limbic System

…recommended (summer) reading: Evil Genes by Barbara Oakley

Anxiety

• hyper-alert, resistant to change, context-dependent

Amygdala

HPA

Hippocampus

Cortisol

Depression• hypo-alert, ahedonia

Manic-Depressive (Bipolar)• waxes and wanes across months/years,

stress is normally a trigger

Robert Schumann’s productivity

Really? A chemical salt to treat bipolar disorder?

• Lithium – can replace Na++ as a generator of action

potentials– centrally decreases norephinephrine release

and enhances serotonin synthesis– efficacious in humans and in mice (see work

of CA McClung [PubMed])

Schizophrenia• severely out-of-touch with reality, delusions of

grandeur, auditory and visual hallucinations, and highly hereditable

Neurobiology of Schizophrenia

Hyperactivity in several brain areas Enlarged lateral ventricles

Increased Dopaminergic Tonus (Euphoria)

The Amygdala

Classes of Affective Disorders and Diverse Brain Dysfunction

• Anxiety– phobias, post-traumatic stress disorder, obsessive

compulsive disorder– Neuropathology: limbic system

• Psychosis– schizophrenia, multiple personality disorder– Neurobiology: dopaminergic system

• Depression– post-partum, manic-depressive– Neurobiology: serotoninergic and noadrenergic systems

Genetic Changes Due to Environmental Stressors (Epigenetics)

• affects DNA transcription and translation which can have a HUGE impact on neuron function

• How? adding of DNA methyl groups, preventing or enabling unwinding of DNA around chromatin, to name a few

• Hugely popular in psychiatric research