Transcript Ch 15 Major Depression

Major Depression & Bipolar
Disorder
Janey, Kevin, & Brittany
Ch 15 Major Depression
• MDD vs Bipolar
• Depression is an affective disorder characterized by loss of
interest or pleasure
• Bipolar disorder (manic-depressive disorder) is
characterized by recurrent episodes of mania and
depression
Ch 15: Major Depression
• Depression and the Brain
– Deficiencies in the brain catecholamines(norepinephrine and
dopamine) are thought to underlie major depressive episodes while
acute drug-induced increases correlate with relief from depression
• inconsistencies in the pattern have also been found
Ch 15: Major Depression
• Effects of Antidepressants
Antidepressasnt drugs may increase the sensitivity of postsynaptic catecholamine and serotonin receptors and may
decrease the sensitivity of presynaptic receptor sites. The
net effect is the reregulation of an abnormal receptorneurotransmitter relationship; speeding up the patient’s
natural recovery process from the depressive episode by
normalizing neurotransmitter efficacy. Stress and other
insults to the brain decrease the expression of BDNF,
which leads to atrophy of vulnerable neurons in the
hippocampus and cerebral cortex; Antidepressant drugs
must work to reverse the atrophy
Ch 15: Major Depression
• Seven Classes of Antidepressants
1. Tricyclic Antidepressants
2. Atypical Antidepressants
3. SSRI’s
4. Dual-Action Antidepressants
5. MAOI’s
6. COMT Inhibitors
7 SNRI’s
Ch 15: Major Depression
• Imipramine vs Fluxetine
– Imipramine is a tricyclic antidepressant that blocks the presynaptic
transporter of protein receptor for either dopamine or
norepinephrine
– Fluoxetine (Prozac) was the first SSRI-type antidepressant
available in the U.S. It blocks the function of the presynaptic
transporter for serotonin reuptake, but does not appear to block
reuptake of other neurotransmitter to any significant degree
Ch 15: Major Depression
• Tricyclics and Overdosing
– The patient that overdoses on tricyclics exhibits excitement,
delirium, and convulsions, followed by respiratory depression and
coma, which can persist for several days. TCA’s are also
cardiotoxic and potentially fatal.
Who’s at risk?
– Children, adolescents and the severely depressed (suicidal) are
particularly at risk
Ch 15: Major Depression
• Side effects of SSRIs
– Anxiety, agitation, and insomnia
• Serotonin Syndrome?
– Occurs when SSRI’s are taken in high doses or combined with
other drugs. Increased central accumulation of serotonin leads to
an exaggerated response, characterized by alterations in cognition
(disorientation, confusion, hypomania), behavior (agitation,
restlessness), autonomic nervous system functions (fever,
shivering, chills, sweating, diarrhea, hypertension, tachycardia),
and neuromuscular activity (ataxia, increased reflexes, myoclonus)
Ch 15: Major Depression
• Serotonin Withdrawal Syndrome
– characterized by disequilibrium (dizziness, vertigo, ataxia);
gastrointestinal symptoms (nausea, vomiting, diarrhea); flu-like
symptoms (fatigue, lethargy, myalgia, chills); sensory disturbances
(paresthesia, sensation of electric shocks); sleep disturbances
(insomnia, vivid dreams);
– psychological symptoms include anxiety, agitation, crying spells
and irritability
– sexual dysfunction occurs in about 60% of patients
Ch 15: Major Depression
• Antidepressants and Children
– TCA’s are considered no more effective than placebo for MDD
– SSRI’s have efficacy in treatment for 13 different conditions
including depression and OCD
• Antidepressants and Anxiety Disorders
– TCA’s, MAOI’s, SSRI’s and venlafaxine XR (effexor) are all in
use for anxiety disorders. The newer antidepressant-anxiolytic
drugs are equally or more efficacious than benzodiazepine-type.
They are less prone to compulsive abuse but impair learning,
memory and concentration to a lesser degree than do the
benzodiazepines
Ch 15: Major Depression
• What is DHEA?
– DHEA is a major glucocorticoid hormone secreted by the adrenal
glands
– It has been promoted (with minimal evidence) to prevent heart
disease, cancer, diabetes, obesity, dementia, aging, multiple
sclerosis, and lupus; it increases feelings of physical and
psychological well being. DHEA, but not placebo, exerted a
robust effect on mood, improving low energy, anhedonia, lack of
motivation, emotional flattening (numbness), sadness, excessive
worry and inability to cope.
– Potential side effects include acne, male-pattern baldness,
hirsutism, voice changes. Also may cause breast or prostate cancer
and liver damage