a framework for psychopathology 1.symptoms 2.neural causes (systems approach) –a. which...
Post on 28-Dec-2015
216 Views
Preview:
TRANSCRIPT
A framework for psychopathology
1. Symptoms
2. Neural Causes (systems approach)– A. Which neurotransmitters?– B. ‘Where’ in the brain? which methods measure it?– Other causes: Genetic, Social
3. Neural Treatment– A. Pharmacotherapy– B. Brain stimulation, lesion– Other (e.g., Cognitive behavioral therapy)
Psychopathology
Diseases with localized lesion• Fronto-temporal dementia (last class)• Orbitofrontal lesion (e.g, Traumatic brain injury)• Strokes & other lesions
– Lesion of medio-frontal structures: Akinetic mutism– Lesion of amygdala: impaired processing of fear
Diseases defined initially by their symptoms• Depression• Obsessive compulsive disorder• Huntington’s disease• Autism• Schizophrenia• ADHD• Anxiety
Depression: Symptoms Possible substrates
• Cognitive processes – Reduced concentration DLPFC– impaired memory hippocampus
• Emotion/motivation/self Mid frontal, OFC– Lack of energy– Loss of interest– Slowness of movement– Mood: Pessimism (depressive realism)
• Autonomic processes Ventral cingulate– Changes in Apetite insula– Reduced libido hypothalamus– Changes in Sleep pattern: (Shallow, Fragmented, Early REM onset)– Increased cortisol levels
Depression: Neural changes
• Change activity in– ventral frontal, – midfrontal, – dorsolateral prefrontal– amydgala
Depression: Treatment
• Cognitive behavior therapy• Pharmacotherapy
– SSRI, acts upon serotonin system– MAOi, – tricyclic antidepressants
• Electroconvulsive therapy• Repeated Transcranial Magnetic Stimulation• Deep Brain stimulation
• Sleep deprivation – Selective (REM)– Total (not feasible)
Relation between Depression and Stress
• Stress “activates” depression in susceptible individuals
• High levels of circulating cortisol in hospitalized depression cases and suicide victims
Relation between Depression & Sleep
• Complete loss of SWS• Increased REM – decreased latency to 1st REM• Decreasing REM -> improved functioning• MAOi suppress REM
Obsessive-Compulsive Disorder (OCD)
Symptoms• Recurrent behaviors (compulsive) • Recurrent thoughts (obsessive)• People repeat things until they feel that they have
“gotten it right”• Frequently related to cleanliness or territoriality
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
Tourette’s syndrome• Dysfunction of cortico-striatal loop • number of D2 receptors in basal ganglia is increased as revelead by PET• tics reduced by D2 antagonists (neuroleptics)
• abnormal cortico-striatal loop may explain aspects of repetitive behavior in OCD, FTD, autism
Huntington’s disease:single dominant gene (50% chance)basal ganglia pathology (caudate nucleus, putamen)mostly GABAergic neuronsstarts at 30- 45 years of agestarts with minor motor problems (twitches, clumsiness)evolves into involuntary jerky movements of eyes, legs also emotional changes (depression, socially inappropriate behavior)emotional changes sometimes precede motor changes
top related