Download Epidemiology of Anxiety

DSM-5 Changes For Anxiety Disorders
• New category of Obsessive-Compulsive and Related Disorders
• Removes obsessive-compulsive disorder from category of Anxiety
Disorders
• Recognizes a spectrum of obsessive-compulsive type disorders
• including body dysmorphic disorder;
• Anxiety remains the core feature of OCD
• New category of Trauma and Stressor-Related Disorders
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Removes Acute Stress Disorder (ASD) from Anxiety Disorders
Removes PTSD from Anxiety Disorders
Groups all stress-related psychological disorders together
Adjustment Disorders may now be coded in context of traumatic
stressors
Comorbidity between Anxiety and Other Mental Disorders
• “Comorbidity among anxiety disorders is quite common, with up to half of the
people with a lifetime anxiety disorder in some surveys meeting criteria for two or
more such disorders. “ (Kessler 2010)
• “Three-quarters (75%) of people with a lifetime anxiety disorder also had at least
one other lifetime mental disorder.” (Kessler 2010)
• Early-onset anxiety disorders are powerful predictors of the subsequent onset and
persistence of other mental and substance use disorders.
• Epidemiology of Anxiety Disorders, (2010) Ronald C. Kessler, p 21-35. M.B.
Stein and T. Steckler (eds.), Behavioral Neurobiology of Anxiety and Its
Treatment, Current Topics in Behavioral Neurosciences
Role of genetics in Anxiety
• The heritability of anxiety disorders is from 30-67% however heritability varies
by subcategory of anxiety disorder
• No single gene but a variety of genes related to function of 5-HT1A, 5-HTT,
MAO-A, COMT, CCK-B, ADORA2A, CRHR1, FKBP5, ACE, RGS2/7 and
NPSR1 (Domschke, 2013)
• Genes for anxiety disorders overlap and transcend diagnostic boundaries
(Smoller , 2008)
• Genetics for anxiety disorders are related to endotypes such as behavioral
inhibition, anxiety sensitivity, increased startle reactivity or dysfunctional
corticolimbic activity during emotional processing (Domschke, 2013)
• Anxiety is similar to temperament and personality traits in that it is a general
phenotypes that predispose for anxiety disorders Na (2011)
Panic Disorder
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Recurrent, unexpected panic
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attacks followed by at least 1 month of persistent concern
about having another attack
worry about the possible implications of the panic attacks
significant behavioral change related to the attacks.
Biological Influences
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Oversensitive respiratory control center in brain stem
Minor oxygen debt (high CO2) false alarm of suffocation
Decreased temporal lobe volumes
Increased activity in parahippocampal gyrus
Decreased activity in anterior temporal cortex & amygdala
Specific Phobia
• Excessive or unreasonable fear related to a specific object/situation
– Most common are snakes & heights
– Some anxiety is adaptive to avoid danger from snakes or falling off cliffs
– Often have associated panic attacks
• Behavioral Explanation
– Classical conditioning example from Little Albert
• However not just classical conditioning
– Evolutionary: Selectivity of phobias
• Why spider but not lamb phobia?
• Why dark but not electric outlet phobia?
– Cognitive: Susceptibility to phobias
• Physiological vulnerability (higher neurological activity)
• Lack of history with stimuli
• Threat-enhancing cognitive set
• Expect threat in environment
• Selective attention to threats
• Selective recall of threats
Generalized Anxiety Disorder
• DSM criteria for GAD include:
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Excessive worry occurring more days than not
Anxiety focuses on everyday events
Person finds it difficult to control the worry
Restlessness, easy fatigue, muscle tension, sleep disturbance
• Biological Influences
– Low GABA levels produces low inhibitory neuron activity
– Lack of inhibition results in high neuronal activity in limbic
system
– High arousal can enhance conditioning
– Anxiolytics increase GABA and decrease anxiety
Posttraumatic Stress Disorder
In posttraumatic stress disorder (PTSD, also called combat fatigue,
war neurosis, or shell shock), unpleasant memories repeatedly plague
the victim.
PTSD victims show:
– Memory changes, such as amnesia
– Flashbacks
– Deficits in short-term memory
• Exposure to actual or threatened death, serious or sexual violence in
one or more of the following ways:
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Direct experiencing of traumatic event(s)
Witnessed in person the events as it occurred to others
Learning that the traumatic events occurred to person close to them
Experiencing repeated or extreme exposure to aversive details of trauma
• Lifetime prevalence of PTSD
– 1–2% in Western Europe
– 6–9% in North America
– over 10% in countries that have been exposed to long-term sectarian violence.
A Neural Model of Posttraumatic Stress Disorder
Obsessive-Compulsive Disorder
• Typical obsessions include contamination, aggressive
impulses, sexual content, somatic concerns, symmetry
• People with OCD may have early life experience with
unacceptable thoughts
• Onset early adolescence to young adulthood, course
typically chronic
• Biological Influences
– Higher activity Orbitofrontal, cingulate and caudate nucleus
– Serotonin dysregulation ?
• Antidepressants (SSRIs) effective for 50% OCD
• Dogs with OCD like behavior improve with Prozac
– At least 2 gene polymorphisms:
• BDNF
• 5-HT2A receptor
Obsessive-Compulsive Disorder
• Obsessive-Compulsive as a distinct disorder
– Because OCD does not result from anxiety
– Compulsions: repetitive thoughts and behaviors
– Similar to:
• body dysmorphic disorder
• Tourette’s syndrome
• Glutamate involvement
– Decision making brain circuits involved
• Immune system (microglia) over activity
– Damage neuronal circuits predisposing some people to
OCD
– Cortical - basal ganglia circuit
Symptoms of Obsessive-Compulsive Disorders
Biological Treatments for Anxiety Disorders
• Benzodiazapines: Bind to GABA receptors
– Valium “Diazepam” for GAD and Phobias
– Xanax “Alprazolam”: for Panic
– 70% individuals show symptom reduction
• Antidepressants: Serotonin agonists
– Paxil, Prozac for GAD, Panic, Agoraphobia,
– Anafranil “Clomipramine” for OCD
– 20-40 % reduction in symptoms for OCD patients
• Neurosurgery
– Cingulotomy–lesions of the cingulate cortex to treat anxiety, depression, and
OCD.
• partially cut cingulate gyrus
• connects lower brain structures with orbitalfrontal cortex
• effective in 50% of cases
– Capsulotomy–lesions of the internal capsule, to treat anxiety disorders.
Psychological Treatments
• Behavioral Treatments
– Extinction of anxiety through exposure and development of
incompatible responses
• Systematic Desensitization
• Progressive muscle relaxation
• Exposure to fear hierarchy
• Cognitive-Behavior Therapy (CBT)
– Challenge threat-magnifying cognitive sets
Psychological Treatment Effectiveness
• Generalized Anxiety Disorder
– CBT more effective than Valium
– CBT + Valium most effective
• Panic Disorder studies
– 75-95% panic-free after 3 months of CBT
• OCD
– Exposure + response prevention
• 50% patients improve