Patho: Psych

• Neurotransmitters

  Serotonin (5-HT) 

  • Involved in depression and bipolar disorder (decreased levels) 
  • It has lots of function even outside of the nervous system - involved in pain perception

  Dopamine  

  • a/w PD - Dopamine is associated with Parkinson's disease due to the degeneration of dopamine-producing neurons in the substantia nigra.
  • a/w dev of schizophrenia 
  • Ppl have disorganized auditory or visual hallucinations, disorganized thinking

  Norepinephrine

  • Lack of it a/w with depression 
  • Meds for depression typically raise serotonin levels or norepi levels in the nervous system
• Neurotransmitters

  GABA 

  • Functions as an off switch  → it inhibits things
  •  So if increase then inhibit neuron from firing that AP 

  Oxytocin

  • Bonding molecule
  • Mom to baby

  Love hormone
• Synaptic cleft: The presynaptic neuron releases neurotransmitters to the synaptic cleft which then bind to the receptors in the postsynaptic cleft. Their function depends on whatever receptor they bind to.

  
• ADHD

  Idea here is that it is on a spectrum. Diagnosis has skyrocketed (1/3-4 people have some form of attention deficit condition). 

  Risk Factors

  Genes

  Smoking

  Alcohol or drug use during pregnancy

  Environmental toxins during pregnancy

  Low birth weight

  Brain injuries 

  Treatment 

  Increase dopamine and norepinephrine
• 5-HTT (serotonin transporter)

  Variation in gene for the 5-HT transporter increases risk for anxiety and depression, alcohol addiction
• Generalized Anxiety Disorder

  Broad anxiety, typically in social components. 

  Believed to originate in neurons in amygdala eventually resulting in SNS activation 

  • Overactive amygdala 

  Often coupled w depression

  Genetic factors are under investigation

  Need to r/o other physical disorder that may present as anxiety 

  • Like not being able to breathe well
• Panic disorder

  On the anxiety spectrum

  • An anxiety disorder with recurrent, unexpected episodes of extreme anxiety
  • Episodes of extreme anxiety that are paralyzing in nature
  • Often physical symptoms that accompany this - chest pain, dif breathing, sweating

  Biological theories suggest a genetic cause

  Locus coeruleus includes 50% of all adrenergic neurons in the CNS – epinephrine is released likely as a fear response originating in the amygdala
• OCD

  A chronic disorder with waxing and waning

  Obsessive  - recurrent thought in the brain

  Compulsive - behavior that alleviates that anxiety

  Etiology and pathophysiology are incompletely understood. There is hyperactivity in orbital frontal cortex. There are abnormalities in serotonin, dopamine and glutamate neurotransmission. Twin studies suggest heredity is involved (80-87%).

  • Might be an overactive part of the brain, abnormalities in dif types of neurotransmitters, prob there is a genetic component.
• Major depressive disorder

  May be a mutation in the gene for 5-HTT (serotonin transporter). 

  Prefrontal cortex shows decreased activity 

  • Issues w norepi and serotonin and dopamine 
  • the 5-HTT gene variation might affect serotonin reuptake, meaning it reuptakes more than it should → leading to less available serotonin for signaling. 
  • Give pt SSRIs 
• Bipolar disorder

  2 types

  Type I - mostly manic 

  Type II - depression is a major problem 

  Occurs in 2.6% of adults 

  • Manic episodes more common in men, depressive in women 

  Often also have substance use and or anxiety disorder 

  Strong genetic predisposition
• PTSD

  Profound anxiety after traumatic or highly stressful event 

  Related to how the memory is linked in the brain to physiological and emotional responses

  • Whatever the memory is that causes them to have PTSD is improperly wired → have abnormal physiological and emotional responses 

  Reasons individuals suffer from PTSD include sexual assault, combat exposure, physical attack,being threatened with a weapon, …
• Schizophrenia

  0.5-1% of US population 

  Disorganized thinking 

  • There will be hallucinations of some sort (auditory, visual)
  • Excess serotonin and loss of GABAergic neurons (the inhibitory ones, calm, sleepy) 

  Theories suggest that there is a genetic vulnerability, and that environment exerts influence in the cause (possibly altered sperm if father was older than 60 at time of birth)
• Delirium

  Transient, usually reversible 

  Often mistaken for dementia or depression

  Can often include hallucinations, delusions, psychotic behavior 

  Up to 56% of hospitalized adults (d/t constant fluorescent lighting, no windows, unfamiliar setting)

  Triggers include hospitalization, p/op state, electrolyte imbalance, infection
• Substance use disorder

  Dopamine reward system - affected 

  There is genetic susceptibility 

  • Specific allele of the D2 receptor (DRD2) is a/w addictive behavior including alcohol and drug use, smoking, obesity, and compulsive gambling 
  • Opiate/ opioid addiction
  • When withdrawing decompensate neurologically 
  • Can have diarrhea (bc opioids typically make you constipated), more pain (if they were taking it for pain before) 
• Substance use disorder

  Benzopam drug withdrawal 

  • More problematic if someone is addicted to taking these and suddenly stops
  • Can affect Cl- channels in the brain → lead to rapid depolarization, individual can have seizures
  • Withdrawing → Has to be tapered