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Psychopharmacology, Neurophysiology & PTSD/Trauma

Psychopharmacology, Neurophysiology & PTSD/Trauma. Presented by Craig Strickland, Ph.D. https://sites.google.com/site/bioedcon strickkat@verizon.net. Learning Objectives. List the 3 general categories of symptoms associated with PTSD

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Psychopharmacology, Neurophysiology & PTSD/Trauma

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  1. Psychopharmacology, Neurophysiology & PTSD/Trauma Presented by Craig Strickland, Ph.D. https://sites.google.com/site/bioedcon strickkat@verizon.net

  2. Learning Objectives • List the 3 general categories of symptoms associated with PTSD • Describe the role of structures in the central nervous system (CNS) associated with these symptoms • Summarize the advantages and disadvantages of the various psychotropic medication classes used to treat PTSD

  3. Overview of the Symptoms of Post-Traumatic Stress Disorder

  4. Major Symptom categories of PTSD • The event is persistently re-experienced • Persistent avoidance of stimuli and numbing of general responsiveness • Negative alterations in cognitions associated with the trauma • Persistent symptoms of increased arousal

  5. Differential Diagnosis • Adjustment Disorder • Acute Distress Disorder • Personality Disorders • Mood Disorders • Other Anxiety Disorders • Psychotic Disorders • Substance Induced Disorders • Other (e.g. medical?) Differential diagnosis is based not just on the mere presence or absence of certain symptoms

  6. Trauma as seen on a continuum Acute Stress Disorder PTSD Chronic PTSD Complex Trauma Symptom Duration & Severity

  7. Overview of the Human Nervous System

  8. Hierarchy of CNS Structures Inferior Parietal (Logical Processing) Prefrontal Cortex (motivation) Cingulate Cortex (attention & affect) Entorhinal Cortex Hippocampus Amygdala (fear/anxiety) Septal Nuclei Lateral Hypothalamus Reticular Formation Peripheral Autonomics

  9. The Hippocampus and PTSD

  10. The Hippocampus

  11. Hippocampus

  12. Normal Functions of the Hippocampus • The hippocampus is a very complex structure • Is part of the Limbic System • Considered “transitional” tissue • Normal functions include (but may not be limited to) • Memory consolidation: works together with newer cortical brain areas • Integration of “emotional tone” with “higher” cognitive functions • Cortex provides semantic influence to the more episodic (factual) “hippocampal” memories • Behavioral inhibition • Inhibitory influence on brainstem activity

  13. The Hippocampus & Trauma • Decrease volume (size) of the hippocampus • This is a robust finding • Vietnam vets: 8 to 26% reduction depending on the study • 7% reduction in women with history of childhood sexual abuse • 16% reduction in hippocampal volume in women with BPD (often associated with a history of abuse) • Seen in other psychiatric disorders such as schizophrenia • Has been shown to occur in animal models involving experimental stressors

  14. Chicken or the Egg?

  15. The Chicken or the Egg? (Gilbertson, et.al. 2002)

  16. Gilbertson, et.al. 2002

  17. Chicken or Egg? (cont.) • Apfel, et. al. (2011) • Gilbertson study did not contain true longitudinal data • This of course would be nearly impossible to do in this type research • Apfel study looked at hippocampal volume in 244 male Gulf War Veterans • Study included those with current PTSD and those where the symptoms of PTSD were remitted

  18. Chicken or Egg? (cont.) • In addition to measuring symptoms of PTSD (using the Clinician Administered PTSD Scale (CAPS) assessment tool: • Measured presence or absence of depression • Measured lifetime drinking history • History of other (non-combat related) stressors • Used structural MRI techniques to measure hippocampal volume

  19. Chicken or Egg? (cont.) • Ended up with four groups of subjects • Subjects with no traumatic exposure • Subjects with exposure but no PTSD • Subjects with a previous diagnosis of PTSD but have recovered • Subjects with chronic PTSD (lifetime and current) • The first two groups had identical hippocampal volume and were combined into one group for the further analysis

  20. Chicken or Egg? (cont.) • Results • Subjects with current/lifetime PTSD • 6.5% smaller hippocampi than those who had recovered from PTSD • Subjects with current/lifetime PTSD: smaller hippocampi by 5.1% than those who had never developed PTSD • Note: there was no difference in hippocampal size between those who never had PTSD and those who had recovered from PTSD • Interpretations?

  21. Chicken or Egg? (cont.) • The results raise the possibility that hippocampal volume is state-dependent and might vary over time e.g. the hippocampus may itself recover from the effects of PTSD; support for this interpretation? • Duration & severity of PTSD symptoms are negatively correlated with hippocampal volume • Hippocampal volume can increase as a result of long-term Paxil treatment • Hippocampal volume might change as a result of exercise, other medications and abstinence from alcohol • E.G. Neurogenesis

  22. Symptoms Associated with Hippocampal Damage? (Re-experiencing) • Dissociation and/or intrusive thoughts • Illusions and/or hallucinations • Behavioral disinhibition: causes the definition of incoming stimuli towards fight/flight responses • Along with amygdaloid activation, hippocampal damage may prevent proper evaluation & categorization of experiences/stimuli • May lead to reacting to new or neutral stimuli as threatening • This would lead to either aggressive behavior or possibly to withdrawal

  23. The Limbic System and PTSD: The Amygdala

  24. Limbic System: The Amygdala

  25. Connections Revisited Inferior Parietal (Logical Processing) Prefrontal Cortex (motivation) Cingulate Cortex (attention & affect) Entorhinal Cortex Hippocampus Amygdala (fear/anxiety) Septal Nuclei Lateral Hypothalamus Reticular Formation Peripheral Autonomics

  26. Normal Functions of the Amygdala • Normal amygdala functioning • Evaluates the emotional significance of incoming stimuli (emotional meaning) • Amygdala activated by feared stimuli (conversely, destroying the amygdala through surgery eliminates fear responses) • Amygdala mediates fear related behaviors • Does so through the hippocampus, hypothalamus and certain cortical areas (prefrontal cortex) • E.g. has an “upstream” and “downstream” effect

  27. Symptoms associated with Amygdaloid hyperactivity (hyperarousal) • Neutral stimuli are seen as fearful • Through connections with other limbic structures, enhanced autonomic and neurohormonal responses • Increased sympathetic nervous system activity • Hypervigilance • Exaggerated startle response • Irritability or outbursts of anger • Increased Hypothalamic/Pituitary Adrenal axis activity (known as HPA)

  28. The HPA • Affected by amygdala activation or lack of hippocampal influence • Increased activity in persons with anxiety as well as persons with depression…hmmm…

  29. Cortical Areas and PTSD

  30. Frontal Cortex Dysfunction Inferior Parietal (Logical Processing) Prefrontal Cortex (motivation) Cingulate Cortex (attention & affect) Entorhinal Cortex Hippocampus Amygdala (fear/anxiety) Septal Nuclei Lateral Hypothalamus Reticular Formation Peripheral Autonomics

  31. Prefrontal Cortex: Activity Decrease

  32. Persistent Avoidance/Numbing • Symptoms include (but not limited to): • Cannot recall important trauma details (memory) • Markedly diminished interest/participation in significant activities • Felling of detachment/estrangement from others • Restricted range of affect (unable to express love, etc.) • Sense of foreshortened future WHAT OTHER DISORDER DO THESE SYMPTOMS REMIND YOU OF? (Are you ready for some “Craigism”?)

  33. MRI of Depression

  34. Dissociative Phenomena (cont.) • “Physiologically, they may respond as if they are being traumatized again, but this may be dissociated from semantic knowledge” (van der Kolk, 1997)

  35. Dissociative Phenomena (van der Kolk) • Failure of left-hemisphere functioning at the time of the trauma (i.e. during extreme arousal) • Decreased activation of Broca’s area (Broca’s area is involved in labeling emotions) • Cannot communicate what is going on, cannot label the internal state • Thus, during extreme arousal/intense emotions, the individual cannot “understand” what is going on • Left-hemisphere: also involved in sequencing events and categorizing experiences. Dysfunction leads to: • Trauma being seen as timeless • Trauma being seen as “ego-alien”

  36. Psychopharmacology and PTSD

  37. Psychopharmacology and PTSD • Issues regarding the use of medications with this disorder • There are no “anti-PTSD” medications (although there are two FDA approved medications for PTSD) • Co-occurring substance abuse disorders • Other co-occurring psychiatric disorders (both Axis I and Axis II diagnoses) • Co-occurring medical disorders • Lack of medication development compared with other disorders

  38. What are the Neurotransmitters? • Monoamines • Dopamine (DA) • Norepinephrine/epinephrine (NE/E) • Serotonin (5-HT) • Gamma amino butyric acid (GABA) and other amino acids (Glutamate, glycine, etc.) • Acetylcholine (ACh) • Hormones • Neuromodulators

  39. Variety of Medications Used • Anti-depressants • Monoamine Oxidase Inhibitors (MAOIs) • Selective Serotonergic Re-Uptake Inhibitors (SSRI)s: Prozac, Paxil, Zoloft, Celexa, Luvox and Lexapro) • Novel Anti-depressants: Desyrel, Serzone • Tricyclic anti-depressants: Elavil, Norpramin • Benzodiazepines • Anti-convulsant mood stabilizers • Anti-adrenergic: Inderal, Clonidine & Guanfacine • Opioid antagonists: Revex, Naltrexone • Anti-psychotic medications

  40. SSRIs: Increase Serotonin Activity • Advantages of the SSRIs (Zoloft, Paxil, etc.) • Can help treat both anxiety and depression • Can reduce impulsivity/enhance sobriety associated with substance abuse • Can be effective in all three symptom clusters associated with PTSD • Behaviors associated with serotonin in the brain include impulsivity, rage, suicidal behavior, depression, panic, obsessional thinking and behaviors associated with substance abuse • Difficult to OD on SSRIs • Disadvantages: do not (nor do any other medications) seem to affect dissociation

  41. Novel Anti-Depressants • Trazodone (Desyrel) • Advantages: • Increases 5-HT similar to SSRIs • Can reverse insomnia caused by SSRI agents and may help reduce traumatic nightmares • Not addictive

  42. Anti-depressants and Lifestyle

  43. Anti-Adrenergic: Decrease NE levels • Inderal, Clonidine and Guanfacine all decrease norepinephrine levels • Advantages: • Reduces hyperarousal and perhaps symptoms of re-experiencing • May help reduce D/A dependence particularly opiate dependence • Side-effects are transient and mild (unless one has pre-existing cardiovascular issues) • Not addictive • Disadvantages: • Half-life is short (tolerance) • Can make co-occurring depression worse

  44. Recent data on NE antagonist • Prazosin: reduces NE activity • FDA approved to reduce BP and reduce enlarged prostate • Used to reduce traumatic nightmares • Not a sedating sleeping pill (does not induce sleep) • Blocking NE centrally may normalize and increase REM sleep • Does not induce tolerance although the beneficial effects wear off once & symptoms return once the drug is stopped

  45. Reducing NE at the time of the traumatic event • Reducing NE shortly after the traumatic event may have two neurological effects: • May have an anti-anxiety effect (established by reducing NE peripherally) • May help reduce memory consolidation by blocking NE centrally (NE activity is part of memories being consolidated ); this may lessen the more long-term reactions associated with stimuli resembling the traumatic event (article in Neuropsychiatry)

  46. Benzodiazepines (BZDs) • Includes meds. such as Valium, Librium, Halcion, Xanax, Ativan • Advantages: • Very effective at reducing anxiety, insomnia and irritability • Reduces these symptoms very quickly • Disadvantages • BZDs have addictive potential • Do not reduce core PTSD symptoms (e.g. re-experiencing, avoidant nor numbing symptoms) • Behavioral disinhibition (similar to alcohol) • Memory interference • Consumers may confuse the sedative properties with the anti-anxiety properties

  47. Anti-Convulsants (Mood Stabilizers) • Includes Tegretol, Depakote and Gabapentin • Advantages: • May reduce proposed “kindling” of limbic structures • Tegretol: may reduce re-experiencing and arousal symptoms • Depakote may reduce avoidant/numbing and arousal symptoms • Disadvantages: • Need to be careful of potential OD (toxicity) • Sedation • Neurontin, Lamictal and Topamax

  48. Opiate Antagonists (Naltrexone, Revex) • The brain: releases increased amounts of endogenous opiates (endorphins, etc.) in response to stimuli which resemble the original traumatic event • This may account for the symptoms of emotional numbing and stress-induced analgesia • Advantages: • May reduce numbing and stress-induced analgesia • May interfere with drug (alcohol/opiate) seeking behavior • Reduce self-mutilation behaviors (BPD) • Disadvantages: • May make hyperarousal/anxiety worse

  49. Eye Movement Desensitization & Reprocessing (EMDR)

  50. Normal Sleep Processes: REM Sleep • Re: memory formation, information flows from the hippocampus to cortical areas during non-REM sleep (basis for reinforcement of old memories) • During REM sleep the flow is reversed • Information flows from cortical areas to the hippocampus and • Hippocampal outflow is blocked • During REM sleep there is a preferential activation of limbic structures (including amygdala) • Thus, REM sleep provides a method of forming new associative links (provides/enhances semantic processes and integrates this with any appropriate emotional tone)

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