TABLE OF CONTENTS - NR 507 / NR507 Bundle Weeks 5 to 8 Notes Advanc...

Chamberlain University

NR 507 / NR507

Bundle Weeks 5 to 8 Notes Advanced Pathophysiology

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TABLE OF CONTENTS

Week 5 – Altera�ons in GI System / Neurobiological Func�on (Depression)

Week 6 – Endocrine System

Week 7 – Neurodegenera�ve Disorders (Alzheimer’s, Demen�a, Parkinson’s)

Week 8 – CNS Brain Disorders & Seizures 2 / 4

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Week 5: Alterations in Neurobiological Function

Depression Major Depressive Disorder (MDD) is known as clinical depression where approximately 20% of females are clinically depressed compared to males at 12%. To be clinically depressed means

that the symptoms experienced interfere with the individual’s daily life. It leads to an overall feeling that life is not an enjoyable experience. The exact cause of MDD is unknown, but most likely due to a combination of genetic, biologic and environmental factors.

• Genetic: Family members who have depression are three times more likely to have it

themselves. This link tends to increase with how close the members are related.

• Biological: From a biological perspective, most medications used to treat depression focus

on the neurotransmitters of the brain. Neurotransmitters are signaling molecules that are released by one neuron and received by receptors of another neuron. A message is

relayed from one neuron to the next. Regulation of how many neurotransmitters are being sent at any given time plays a significant role in the development of the symptoms of depression since they are involved in the regulation of many brain functions like mood,

attention, sleep, appetite and cognition. The three major neurotransmitters that are involved in the development of depression are serotonin, norepinephrine and dopamine.These are significant because medications that cause there to be more of these neurotransmitters in the synaptic cleft (the space between the neurons) are shown to be effective antidepressants. This finding led researchers to develop the Monoamine Deficiency Theory that indicates that the underlying basis of depression is low levels of serotonin, norepinephrine and dopamine. These are known as monoamines because they

have one amine group. In addition, it is thought that each of these may have an impact on

certain sets of symptoms of depression:

o Serotonin: obsessions and compulsions

o Norepinephrine: anxiety and attention

o Dopamine: attention, motivation and pleasure

• If one of these neurotransmitters are low a specific set of symptoms may be

experienced by the individual. Serotonin, particularly, is thought to be a major player. Some theories suggest that it may be capable of regulating the other neurotransmitters, norepinephrine and dopamine. However, there is limited

evidence to support this theory. More concrete evidence that supports the role of serotonin in the development of depression, relates to tryptophan depletion. This is

the amino acid that the body uses to make serotonin. If there is a decrease in tryptophan, there will be a decrease in the production of serotonin. Without a normal level of serotonin, individuals begin showing symptoms of depression.However, the reasons why serotonin, norepinephrine and dopamine might be decreased in patients with depression is not well understood. Thus, significant resources are dedicated to continuing research in this area.

• Environmental: Environmental components include loss from death or from sexual or

physical abuse.

• In order to diagnosis MDD, patients must meet certain criteria that are outlined in

the Diagnostic and Statistical Manual, 5th edition (DSM-5) for Mental Disorders.

• The patient must be affected by at least five of nine of the following symptoms

mostly or every day, for at least 2 weeks:

▪ Depressed mood ▪ Diminished interest of pleasure in activities ▪ Significant weight loss or gain ▪ Inability to sleep or oversleeping 3 / 4

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▪ Psychomotor agitation (pacing, wringing hands, psychomotor impairment or overall slowing of thought processes) ▪ Fatigue ▪ Feelings of worthlessness or guilt ▪ Decreased ability to think or concentrate ▪ Recurrent thoughts of death or suicide ideations (including suicidal thoughts with or without a specific plan and/or suicide attempt)

• The symptoms must cause distress in the individual’s daily life.
• The symptoms cannot be due to a substance or other medical condition.
• The symptoms cannot be better explained by another mental disorder (e.g.

schizoaffective disorder).

• The individual cannot have had a manic or hypomanic episode at any point.

MDD Sub-Types

MDD may be divided into sub-types of closely related conditions:

• Post-partum depression: Occurs following childbirth. Although studies have shown that it

can occur prior to childbirth as well. The actual diagnosis is Depressive Disorder with

Peripartum Onset because the onset occurs during pregnancy or four weeks following delivery. The cause is generally unknown but is suspected that hormonal factors play a role in its development, especially estrogen and progesterone. The impact of childbirth on lifestyle may also play a role in its development because it can happen in men as well as in women.

• Atypical depression: This is characterized by an improved mood when exposed to

pleasurable or positive events. This is known as mood reactivity in contrast from other subtypes like melancholy even during what used to be pleasurable events. Atypical

depression also includes the symptoms of weight gain, increased appetite, oversleeping, heavy feeling limbs (leaden paralysis) and rejection sensitivity where the individual feels anxiety at thoughts of rejection.

- Dysthymia: persistent depressive disorder used to describe milder symptoms of

depression that happen over longer periods of time, specifically over two or more years

with at least two of the following symptoms:

• Change in appetite
• Change in sleep
• Fatigue or low energy
• Decreased self-esteem
• Decreased concentration
• Feelings of hopelessness or pessimism

Treatment: Non-Pharmacologic Approaches

Awareness of the many factors involved in the diagnosis of depression can pose treatment challenges. With the correct treatment, the individual can have a significant reduction in

symptoms. Treatment can come in several forms and are grouped into one of two major categories non-pharmacologic, and pharmacologic approaches. Non-pharmacologic approache s

include:

• Physical activity is thought to be related to the release of neurotransmitters, endorphins,

and endocannabinoids as well as raising the body temperature to cause muscle relaxation.Regardless of the exact mechanisms, data suggests that exercising for 20 minutes for three times per week can help alleviate symptoms of depression.

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