MIND MATTERS: The Neuroscience of Child Anxiety. Dr. Catherine McCarthy Child and Adolescent Psychiatry McLean, VA

Transcription

1 1 MIND MATTERS: The Neuroscience of Child Anxiety Dr. Catherine McCarthy Child and Adolescent Psychiatry McLean, VA

2 I Everything you hear later today is grounded in neuroscience

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4 My Favorite Things Neuroplasticity Neuroscience of Anxiety CBT

5 5 Neuroplasticity of Developing Brain Adolescence is a time of dynamic brain growth and change Huge ramifications in the development and treatment of anxiety (REGULATION CIRCUITS OF ANXIETY RESPONSE BEING SCULPTED) Giedd, Weinberger et al., 2005

6 6 Neuroplasticity Number of neurons may not change much, but synaptic complexity (neuronal connectivity) is the most critical change that occurs after birth

7 7 Dendritic Arborization Giedd, Weinberger et al., 2005

8 8 Computer Imaging Model Paul Thompson, Ph.D., UCLA Laboratory of Neuroimaging

9 9 Computer Imaging Model Paul Thompson, Ph.D., UCLA Laboratory of Neuroimaging

10 10 Functions of the PFC CEO of the Brain Controlling impulses Executive functioning Inhibiting inappropriate behavior Initiating appropriate behavior Stopping an activity upon completion Shifting/adjusting behavior when situations change Providing a temporary mental workspace for working memory Organize things Forming strategies and planning behavior Setting priorities among tasks and goals Making decisions Empathy Sensitivity to feedback (reward and punishment) Insight

11 PFC for the purpose of today WISE, RATIONAL, REASON part of the brain Helps us see the middle ground, the gray between black and white Helps us not think in extremes, not all or none thinking REGULATES anxiety circuits TOP-DOWN LAST to develop DEVELOPMENTALLY, LAST to develop EVOLUTIONARILY

12 Mammal Frontal Lobe Evolution Catherine McCarthy, M.D. 33% of brain volume Well developed in primates only Human species difference is due to frontal lobe (PFC)

13 13 CAPITALIZING ON NEUROPLASTICITY windows of opportunity for use it or lose it Giedd, Weinberger et al., 2005

14 Very Cool Study: CAPITALIZING on Neuroplasticity Developmental Cognitive Science (Whittle, S., et al, 2013) Title: Positive parenting predicts development of adolescent brain structure: A longitudinal study Paper highlights parenting (and teaching???) and plasticity

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16 The Converse: Plasticity and Stress Brain Plasticity of this pubertal period makes kids more vulnerable to the effects of stress (and practicing being anxious)

17 THE NEUROBIOLOGY OF THREAT CIRCUIT AND ANXIETY

18 Frontal Lobes = PFC Amygdala

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20 The innervation of the parasympathetic nervous system from limbic structures is thought to mediate visceral symptoms associated with anxiety.

21 THE THREAT CIRCUIT: FIGHT/FLIGHT/FREEZE RESPONSE

22 If you re a regular mammal, it is about three minutes of screaming terror on the Serengeti savannah after which it s either over or you re over. -Robert Sapolsky

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24 BACTERIA/ACID

25 Dr. Joseph LeDoux (see book ANXIOUS) King of mapping the threat circuit Rockstar of the anxiety disorders (with Dr. Daniel Pine) 1980 s he mapped neurocircuitry of the defensive fight/flight/freeze response in rats No amygdala, no freezing LOW ROAD/Shortcut vs HIGH ROAD from threat detection to amygdala

26 Dr. Joseph LeDoux (see book ANXIOUS) TWO THREAT DETECTION ROUTES TO THE AMYGDALA LOW ROAD/Shortcut IMMEDIATE THREAT DETECTION, NOT CONSCIOUS vs HIGH ROAD CONSCIOUS AWARENESS COMES AFTER THE INITIAL THREAT RESPONSE

27 Amygdala: Threat Detection and Response: NOT CONSCIOUS, LOW ROAD ALARM SYSTEM: -Amygdala SCANS FOR DANGER SIGNALS (does not need cortex to scan) Low Road/SHORTCUT (NOT conscious): -Sensory thalamus----amygdala (10 millisec) -Vis/auditory through thalamus -Smell/touch straight to amygdala quick and dirty processing system -LeDoux

28 Amygdala Defense Low Road Unleashes defense system instantly before threat is consciously registered When we encounter something that looks like a threat, we do unconsciously bottom up capture of attention ex. Walk in the woods/snake Unlike the higher road (when cortex afterwards registers threat)

29 Higher road to Amygdala: Conscious cortex more circuitous route comes after High Road (only after the fear response is activated, does the conscious mind kick into high gear Sensory thalamus --SENSORY CORTEX amygdala Cortex analyzes raw data and decides whether requires real fear response If yes (wise mind?), cortex signals the amygdala and body stays on high alert

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31 Physiology of Amygdala response Perceived danger sets off AMYGDALA Lateral Nucleus (LN) of amygdala: receiving zone for dangerous information/senses Central Nucleus (CN): sends info to parts of brain to control physical responses of fear Two paths for amygdala to generate adrenaline response

32 Two Paths to Panic from the Amygdala 1) Sympathetic nervous system is activated (all or none phenomena)- Extrahypothalamic stress response Amygdala (Locus Ceruleus) Sympathetic Nervous System directly to release NE/adrenaline 2) Amygdala hypothalamus-pituitary adrenal gland cortisol NE/adrenaline

33 Bodily Experience of NE/adrenaline/cortisol Increase in heart rate and strength of heartbeat to speed up blood flow Blood is redirected from places it is not needed (skin, fingers and toes) to places where it is more needed (large muscle groups like thighs and biceps) Respiratory effects-increase in speed and depth of breathing Sweat gland effects-increased sweating

34 No amygdala is exactly like another The amygdala we inherit may be more or less sensitive to potential dangers (correlate: risk of future anxiety disorders ) Example: MRI differences in size of amygdala in children with anxiety

35 Relation between childhood anxiety and amygdala morphometry S. Qin et al. 2014

36 How does the Amygdala learn? (take advantage of this in CBT/ERP) Some fears are WIRED IN to the amygdala (snakes/heights/being watched by others with human and genetic variability) Other fears are learned and stored by the Amygdala (not the way the cortex learns) Amygdala learns through experience on basis of PAIRINGs (NOT logic/pfc)--

37 The Language of the Amygdala (we take advantage of this in Exposure therapy) Amygdala learns through experience on basis of PAIRINGs (NOT logic/pfc) Pavlov/classical conditioning Associative learning based on pairings Process of Extinction: shaking the fear, exposure tx

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39 Extinction: how to shake the fear response LeDoux 1990s: rats that have been fear conditioned by pairing of tone with shock can override learning/fear response when tone given no shock Basis of Exposure Therapy

40 Extinction: also involves the cortex/pfc Medial PFC: critical to extinction, dampens down the amygdala Medial PFC clamps down on amygdala, like the brakes, and the amygdala is the accelerator J. LeDoux

41 Cortex-Amygdala 2 Way Street The same circuits that cause anxiety are what we use to manage anxiety/prevent anxiety Top Down (Cortex Amygdala) Vs -cortex thought circuits can SET OFF anxiety responses -and CLAMP down anxiety response (CBT) Bottom Up (Amygdala Cortex) Fight/flight-(amygdala inhibits PFC, not conscious initially) Learning through extinction (exposure-pairings)

42 Anxiety happens when thoughts (cortex) interact with threat-defense mechanism J. LeDoux: ANXIOUS While our body goes into fight or flight mode, our mind conjures up catastrophe and dredges up memories of prior peril - A. Peterson, On Edge Result: Conscious Experience of Anxiety

43 Bed Nucleus of the Stria Terminalis (BNST) Unlike amygdala, which sets off emergency burst of fear, BNST perpetuates the fear response, causing longer term unease typical of anxiety the Extended Amygdala

44 BNST: the Extended Amygdala M. Davis Fear and Anxiety may originate in different parts of the brain Amygdala tied to fear, raw immediate response to threat BNST involved in sustained fear reactions long lasting amorphous unease typical of anxiety BNST: switched on by apprehension

45 SUSTAINED UNCERTAINTY C. Grillon Sustained Uncertainty and the startle reflex In a way anxiety is the opposite of fear. Fear is about something that is in front of you that is predictable and imminent. Anxiety is the opposite. It is worrying about something that is in the future that may or may not happen.

46 Chronic Stress and the PFC See shrinkage in the PFC from chronic stress-- Dr. Dan Goleman has said, Stress makes us stupid. Amygdala (brain s threat detector) works overtime, actually gets bigger PTSD: hippocampal volume differences The more anxious and stressed you are, the more anxious you become. Dr. William Stixrud

47 Chronic stress/fear can be extra tough for kids and teens compared to us old folks: immature PFC, developing plastic brains

48 Reading emotion and risk taking behavior: D. Yurgelun-Todd fmri study of brains of children age compared to adult brains both groups shown pictures of adult face and asked to identify emotion on faces fmri traces what part of brain responds to picture (Yurgelun-Todd, PBS, 2002)

49 Teen vs adult response to face pic (Yurgelun-Todd, PBS, 2002)

50 Adults: identify face as fear used frontal cortex Teens: shocked, surprised, angry used amygdala (Yurgelin-Todd, PBS, 2002)

51 Brains reading emotion (PBS, 2002)

52 Early life: Stimulus amygdala automatic response (emotion/fight or flight) Later Life: Stimulus PFC more reasonable, rational (thoughts)

53 ENTER the PFC/Neuroplasticity/CBT triad TOP DOWN -COGNITIVE MODULATION OF FEAR/ANXIOUS STATES CORTEX BEHAVIORAL THERAPY=COGNITIVE BEHAVIORAL THERAPY CAPITALIZING ON NEUROPLASTICITY TO WIRE KIDS DEVELOPING PFC

54 PFC : USING OUR THINKING/LOGIC BRAIN CONNECTS TO AMYGDALA THROUGH MULTIPLE REGIONS GABAergic neurons (inhibitory/brakes role of PFC over amygdala function) Neuroimaging studies in humans show inverse relationship between amygdala and multiple PFC regions including the VM PFC, VL PFC, and DL PFC CBT parent/therapy interventions target the Cortex (WHAT YOU LEARN ABOUT REST OF TODAY!)

55 PFC : USING OUR THINKING/LOGIC BRAIN IN ANXIETY DISORDERS, THERE IS ABNORMAL TOP DOWN OR COGNITIVE MODULATION OF ANXIOUS STATES THAT MAKES IT HARD FOR THE THINKING BRAIN TO SHUT DOWN THE IRRATIONAL ANXIETY --D. Vergne, 2014 We have the most control over this part of our brain and can impact it (AND MOLD IT) if we WORK it (CBT)

56 PFC : USING OUR THINKING/LOGIC BRAIN CBT: does not directly change the amygdala s functioning once activated, the amygdala can t be argued with (adrenaline threat circuit unleashed has to run its course)- CBT: best used to prevent the cortex from activating the amygdala s alarm response and creating different pathways of practiced thought patterns GOAL: PREVENT THE CORTEX (thoughts) from Activating the Amygdala for not true thoughts

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59 Neuroplasticity in Response to CBT for Social Anxiety Disorder Translational Psychiatry Swedish study K N T Månsson et al., 2016

60 CBT Normalizes brain in Social Phobia Decrease in the thickness of the cerebral cortex after psychotherapy in the left parietal cortex (marked in red). V R Steiger et al. 2017

61 Increased Right VLPFC Activation in Adolescents with GAD treated with CBT vs Controls J. Maslowsky et al., 2010

62 Other ways to wire the human brain to best manage anxiety MEDITATION-BDNF Mindfulness Exercise--BDNF Sleep Could have an entire lecture on the massive impact of these alone

63 63 Remember: Windows of accelerated brain change = windows of opportunity

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