Brain in trouble
Inhoudsopgave
Week 1: Addiction, Impulsivity & ADHD ........................................................................................................... 2
Introduction to Brain in Trouble ......................................................................................................................... 2
Etiology of mental traits and conditions ............................................................................................................ 3
Impulsivity ........................................................................................................................................................ 13
Addiction is a brain disease I ............................................................................................................................ 20
Addiction is a brain disease II ........................................................................................................................... 28
ADHD ................................................................................................................................................................ 33
Neurodiversity for ASD & ADHD ....................................................................................................................... 42
Week 2: Cognitive enhancers, deep brain stimulation & eating disorders ...................................................... 44
Introduction to (ab)normal behavior ................................................................................................................ 44
Obesity – body weight regulation, pathophysiology and treatment ................................................................ 45
DBS in psychiatry .............................................................................................................................................. 61
Healthy brain – part 1 – introduction ............................................................................................................... 67
Healthy brain – part 2 – Increasing Peak Performance .................................................................................... 74
Healthy brain – part 3 – increasing well-being ................................................................................................. 76
Healthy brain – part 4 – gratitude letter .......................................................................................................... 79
Healthy brain – part 5 – increasing well-being ................................................................................................. 79
Cognitive enhancers ......................................................................................................................................... 83
Week 3: Mood & social behaviour ................................................................................................................. 90
Depression – part 1........................................................................................................................................... 90
Depression – part 2......................................................................................................................................... 101
The bright side of mental illness – resilience .................................................................................................. 104
Neurobiology of morality and antisocial behaviour I ..................................................................................... 111
Part 1 – ASPD vs psychopathy ................................................................................................................... 111
Part 2 – neuroimaging studies ................................................................................................................... 113
Part 3 – empathy in psychopaths .............................................................................................................. 115
Part 4 – neurodevelopmental basis of antisocial behavior ....................................................................... 116
Part 5 – Environmental and genetic factors .............................................................................................. 120
Part 6 – are psychopathic tendencies always a bad thing? ....................................................................... 121
Real-life neuroscience ..................................................................................................................................... 123
,Week 1: Addiction, Impulsivity & ADHD
Introduction to Brain in Trouble
ADHD - Lifetime-prevalence of ADHD is 3-5% in adults and 4-8% in children.
Lifetime- prevalence = it occurs at some time in your life.
Eating Disorders Statistics -
• Lifetime-prevalence of anorexia nervosa, boulimia nervosa, binge-
eating disorder and other eating disorders varies from less than 0.5%
up to 2,5%.
• Almost 50% of people with eating disorders meet the criteria for
depression.
• Only 1 in 10 men and women with eating disorders receive
treatment.
• Eating disorders have a high mortality rate
Deep brain stimulation in Psychiatry – OCD, Depression.
Depression is a major cause of morbidity worldwide
• Lifetime prevalence varies widely, from 3% in Japan to 17% in the US.
• In most countries the number of people who would suffer from depression during their
lives falls within an 8–12% range.
,Etiology of mental traits and conditions
Trait or disorder?
• Impulsivity, mood, (anti) social behaviour, stress-sensitivity, resilience and
vulnerability are behavioural traits
• Each trait exists along a spectrum
• Impulsivity (extremely thoughtful, difficulties decision taking – extremely impulsive)
• Border between normal and abnormal behaviour? (What is normal? What is
abnormal? Who decides this?)
• A variation or a disorder?
• Other traits: IQ, extraversion, blood pressure…
• Disorders: diabetes, obesitas, autism (?), depression, schizophrenia
HOW do traits and disorders arise in general?
Which factors can contribute to traits / (mental) characteristics and brain disorders – genes,
environmental factors (stress, alcohol, family, pregnancy, food).
Nature – Nurture discussion
• Past: tendency to explain disease via ‘nurture’ concept
• Autism = ‘refrigerator mother’ (cold) – having a cold and distant mother
• Homosexual orientation = overly present mother
• Later: role biological factors clearer (‘nature’)
Etiology
Etiology is the study of the causes, origins, or reasons behind the way that things are, or the
way they function, or it can refer to the causes themselves. -> Wikipedia
Classical nature – nurture discussion:
• Hard reductionism: ‘all psychiatric illness is best explained solely in terms of
molecular neuroscience’.
But etiological models for psychiatric disease need to be pluralistic or multilevel in order to
explain mental traits and psychiatric illness. Best understood from biological, psychological
and sociocultural, economic perspectives. Break down dichotomy between nature-nurture,
but view brain as in constant interaction with environment, society and culture via plasticity.
Some traits have a more nurture load and some more nature, but there is a constant
connection, and they are shaping traits.
Most brain disorders are complex (several factors to shape), multifactorial disorders.
Both genetic and environmental factors involved in etiology. Often: complex interactions
and causal loops. Not one cause.
Genes
, From twin + adoption studies; several behavioral traits and psychiatric diseases moderate /
high heritability.
Heritability = proportion of variance in symptoms that is explained by the variance in genetic
factors. So, 75% heritability does not mean that you have 75% probability that you have it. It
is a variable at population level, not individual level. The variation you see in their symptoms
can be explained by the variation among these people.
Major depression: 40-50%. ADHD: 75%. Autism, bipolar disorder, schizophrenia around 80%.
‘Human genome project’ – Expectation: easy to find risk genes. Contrary: very difficult.
‘Missing heritability’ = The missing heritability problem arises from the difference between
heritability estimates from genetic data and heritability estimates from twin and family data
across many physical and mental traits.
But: we KNOW genes play a substantial role.
Model of single / few risk genes = overly simplistic paradigm.
Genes and Psychiatry
Classical theory = single genes cause mental illness.
Single abnormal gene > abnormal gene product > neuronal malfunction > mental illness.
Single abnormal gene is not sufficient to cause mental disorders.
What is pathway from gene to mental illness?
New explanations, new hypotheses, new models for pathway ‘genotype to phenotype’
• 1. ‘Complex Genetics’ or ‘Diathesis-Risk Model’ (explained in lecture Etiology)
• 2. ‘Differential Susceptibly to Environment Hypothesis’ (explained in lecture
‘Neurobiology of Resilience’)
• 3. ‘Balancing Selection Hypothesis’ (explained in course Molecular Principles of Brain
Disorders, minor Neuroscience)
New hypotheses and new models are complex.
New ways of doing research and ‘unravel’ these pathways from ‘genotype to phenotype’ ->
‘endophenotype approach’ -> (in between) means endophenotype.
Stress – diathesis model’ (diathesis = risk). Stress increases your risk.
Predisposition (genetic) + environmental stress > disease.
New paradigm:
- Hypothesis: mental illness is caused by multiple small contributions from several
genes, all interacting with environmental stressors > ‘Complex genetics’.
- Complex set of risk factors that bias person toward illness but do not cause it
(inherits risk not disease).
- Reaching tipping point: high probability of developing disorder (threshold).
- Concept also applies to hypertension, obesitas, diabetes.
