HMB300H1 Lecture Notes - Lecture 4: Deep Brain Stimulation, Learned Helplessness, Reserpine
Lecture 4
Depression & Hormonal Influences
• Increases in glucocorticoid levels ae found in depressed people
• Animal models inject elevated levels of glucocorticoids (corticosteroids) which affects mobility and
motivation
• Hormonal changes can also mimic depressive symptoms but hormonal changes do not respond well
to antidepressants
o Birth and post-partum depression
o Different times of period
o Menarche and menopause
• Suggests hormonal changes in some people may cause depression
Neuroscience Correlates
• Anhedonia: inability enjoy anything
o Correlated with VTA and NAcc
o Loses of sexual desire, warm feelings, happiness, blame or self-guilt
• Psychomotor effects: inability to do anything
o Vegetative symptoms such as disruption of sleep cycles, appetite change, stress responses,
etc.
Depression links to the endocrine system
• Hashimotos disease: chronic lymphatic thyroiditis (autoimmune disorder that destroys the thyroid
gland)
o Most common cause of hypothyroidism
o Symptoms = fatigue and sluggishness, anxiety, trouble sleeping, and weight changes, and
depression
o Affects women more
• Cushing syndrome: abnormally high levels of the hormone cortisol (glucocorticoids)
• Fall into depression as well
More Evidence for Hormones
• Dexamethasone test: used to test for Cushing syndrome bc it looks at whether cortisol goes up or
down
o Suggests HPA axis is very important
o Cortisol receptor blockers RU- 486 sometimes used as a non-traditional remedy for
depression
Neurotransmitter hypothesis
• Most commonly used hypothesis to explain changes in moods
o Monoamines play a pivotal role in behavior
o Both animal models and human models (substance abusers) give evidence that changes in NT
affect mood
• PET studies show differences in areas of the brain associated with specific NTs