This is a draft cheat sheet. It is a work in progress and is not finished yet.
PSYCHOSIS
A Sx of mental illness characterized by the loss of contact with reality |
Manifestations |
Hallucinations |
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Disorganized thoughts and speech |
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Emotions exhibited in an abnormal manner |
────────── Causes ────────── |
Functional |
Schizophrenia |
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Manic phase of bipolar disorders |
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Psychotic depression |
Organic |
Alzheimer's Disease |
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Other causes of dementia |
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Brain tumors |
Drug Abuse |
Cocaine |
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Amphetamines |
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PCP ("angel dust") |
STRUCTURAL ABNORMALITIES IN SZ
Decreased cortical thickness in the absence of gliosis |
Reduction in the volume of the frontal love, medial temporal lobe, thalamus, and hippocampus ➩ increased ventricular size |
Decreased blood flow and glucose metabolism in the frontal lobe and left temporal lobe |
Abnormal (excessive) synaptic pruning ➩ decreased umber of glutamatergic dendritic spines in PFC |
Risk is increased if a specific variant in a gene related to synaptic pruning ➩ Complement Component 4 (C4) |
Gliosis: the proliferation of glial cells ➩ occurs as a compensatory change in the degenerative diseases in the brain (typically later in life)
Synaptic Pruning: the process of synapse elimination that occurs between age 2 and onset of puberty
C4: plays a role in the immune system and also in brain development
Neurotransmitters
Multiple NT systems interact to cause the signs and sx of SZ |
Functional abnormalities are related to alterations in: |
Dopamine |
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Glutamate |
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Serotonin |
Positive Symptoms
Disorganized speech, thoughts, and beliefs |
• May lose track of their ideas, meanings, and words (word salad) |
• Thought processes are disconnected (loose associations) |
• Ideas and images may become jumbled or linked together illogically |
• Words and meanings that should be linked may become diconnected |
Disorganized Movement and Behaviors |
• May use exaggerated or repeated gestures |
• May seem to be fidgeting, hyperactive, or preoccupied with meaningless physical movements |
Cognitive Symptoms
Impaired Attention |
• Trouble focusing or paying attention |
Impaired Working Memory |
• Ability to use information immediately after learning it |
Poor Executive Function |
• Ability to understand information and use it to make decisions |
Patients often have difficulty learning from their experiences and can repeatedly make the same mistakes in situations requiring judgment
Poor insight into the severity of their disorder; tend to d/c therapy
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SCHIZOPHRENIA (SZ)
Epidemiology |
Onset |
Most common in young adults |
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Onset before adolescence or after 40 yr is extremely rare |
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Onset in males occurs earlier than females |
Prevalence |
Equal (male vs female) |
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In general, better outcomes in females |
Suicide |
~ 15% |
Etiology |
Unknown |
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Cause is multifactorial |
Genetics |
Significant genetic component with a complex, non-Mendelian inheritance |
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Greatest risk factor ➩ positive family hx |
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Many genes involved ➩ pt's inherit several risk genes |
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➩ SNP's and CNVs |
Environmental |
Pt's more likely to experience: |
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• premature birth |
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• low birth weight |
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• perinatal hypoxia |
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Maternal viral infxn during pregnancy (especially during the 2nd trimester) |
Early Neurodevelopmental Defect |
Brain vulnerability by genetic predisposition |
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Combined with environmental factors or stressors |
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➩ Abnormal migration of neurons during CNS development |
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➩ Results in Abnormal neuronal connectivity and abnormal brain circuits |
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➩ Schizophrenia |
SZ is more frequent in people born in cities and born between January and April (northern hemisphere)
SNPs: single nucleotide polymorphisms
CNVs: Specific copy number variations
Dopaminergic Pathways in the Brain
Nigrostriatal |
Originates in the substantia nigra |
Projects to the striatum |
Negative Symptoms
Alogia and Poverty of Speech |
• May speak very little |
• Speech may have little meaningful content |
• May have long delays between words and sentences |
Flattening or Blunting of Affect |
• May have reduced emotional expression |
• May not smile or frown in response to happy or sad events |
• Voices may not change tone or pitch |
• May not maintain eye contact or other kinds of emotional links with people |
Anhedonia and Avolition |
• May seem to lose interest in and energy for pleasurable activities and achievements |
• Lack of desire, drive, or motivation to pursue meaningful goals |
Catatonia and Posturing |
• May freeze into unusual body positions |
• May stop moving entirely |
• Sometimes hold rigid poses for hours and will ignore external stimuli |
• May show stereotyped repetitive movements |
Lack of Motivation and Social Withdrawal |
• Contribute to poor-self care skills |
• Difficulties maintaining employment and living independently |
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