ASD and ADHD

Learning Outcome

Discuss the biological and psychological origins relating to ASD and ADHD

ASD – a Brief History1911 AD – Eugen Bleuler, a Swiss psychiatrist was the first person to use the term ‘autism’. He did so when referring to one group of symptoms of schizophrenia.

1943 AD – Leo Kanner published a paper where he used the term autism to describe the withdrawn behaviour of several children he studied.

1944 AD – Hans Asperger published a paper in which he identified a similar condition which is now known as Aspergers syndrome.

Psychological Origins1949 Leo Kanner suggested autism may be related to a “genuine lack of maternal warmth”

1949 Kanner observed children were exposed to “parental coldness, obsessiveness, and a mechanical type of attention to material needs only”

1960 Kanner described parents of autistic children as “just happening to defrost enough to produce a child.”

Psychological OriginsBruno Bettelheim – a professor and child development specialist facilitated the widespread acceptance of the refrigerator theory in the 1950’s and 60’s.

He championed the theory that autism was the product of mothers who were cold, distant and rejecting, thus depriving their children of the chance to “bond properly”.

Bettelheim founded the Orthogenic School as a residential treatment centre for autistic children who he felt would benefit from a “parentectomy”.

Bruno Bettelheim

"The difference between the plight of prisoners in a concentration camp and the conditions which lead to autism and schizophrenia in children is, of course, that the child has never had a previous chance to develop much of a personality.”

Persistence of the Theory1991 – Peter Breggins book Toxic Psychiatry says the psychogenic theory of autism was abandoned for political pressure from parents and not for scientific reasons. He insists that profound institutional privation can lead to quasi-autistic symptoms.

Francis Tustin wrote -There is persistent denial by American society of the causes of damage to millions of children who are thus traumatized and brain damaged as a consequence of cruel treatment by parents who are otherwise too busy to love and care for their babies.

Modern Alternatives

The modern consensus is that autism has a strong genetic basis, although the genetics of autism are complex and are not well understood. Although recent studies have indicated that maternal warmth, praise, and quality of relationship are associated with reductions of behaviour problems in adolescents and adults with autism, and that maternal criticisms are associated with maladaptive behaviours and symptoms, these ideas are distinct from the refrigerator mother hypothesis.

Biological ConceptsThe History

• 1988-1991 Many studies related to Autism and genetic connection.

• 1992 The American Psychiatric Association refines the diagnostic criteria for Autism.

• 1997 The first report with evidence linking chromosome 15q for Autistic disorder.

• 1998 Genetic linkage from chromosome 7q to Autistic disorder and the first genomic screen -- IMGSAC.

• 1999-2001 During this time evidence was found in genomic regions that have possible genes that are associated with autism.

Biological Concepts

• Experts say that at least two genes and up to fifteen genes are involved with autism development.

• Autism genes maybe located on the second, third, seventh, fifteenth and”x” chromosome.

• Unsure if act independently or with each other

• In 2003 Duke University found a link from GARB# gene to autism.

Biological Concepts

• Chromosome 2 maybe linked to delayed speech.• Chromosome 3 possesses a gene that produces a

protein that interacts with GABA. If the GABA is not functioning properly it may cause autistic behaviors.

• Chromosome 7 is associated with many functions speech, language, cell fate, nervous system in foetus and adults, and development of the brain.

• Chromosome 15 has three GABA receptor genes.• Chromosome X may be involved with social

interaction.

Biological Concepts

De novo mutations are not inherited but occur spontaneously near or during conception. Most people have at least one, and the majority of them are harmless.

Everyone typically has at least one de novo mutation, but preliminary studies in this area suggest that “kids with autism have a slightly higher rate, on average, and the effects are more severe.”

Point for DiscussionWhat came first?

Preliminary studies have found evidence that the risk of de novo mutations increases with parental age. In an analysis of 51 de novo mutations, it was found that glitches were four times more likely to originate in DNA from the male than from the female. The risk is higher in fathers at 35 than at 25 and seems to creep up with age.

Neurobiological ConceptsDr. Eric Courchesne using MRI scans of normal subjects and autistic individuals has found that certain areas of the cerebellum are underdeveloped in autistics.

The cerebellum is primarily responsible for motor movements, but may also play a role in speech, learning, emotions, and attention. Thus, cerebellar abnormalities may help to explain the aberrant motor activity, impaired cognitive abilities, and apparent lack of emotion that are characteristic of autism.

Neurobiological Concepts

There is also evidence that autistic individuals have dramatically reduced levels of Purkinje cells in the cerebellum. These cells, which are rich in the neurotransmitter serotonin, transmit inhibiting messages from the cerebellum to areas of the cerebral cortex. Given that the cerebral cortex is thought to be the centre of thinking and judging, the dearth of communication with this area may help to explain some of the cognitive deficits characteristic of autism.

Neurobiological ConceptsImaging studies have revealed that autistic children have too many nerve fibres, but that they're not working well enough to facilitate communication between the various parts of the brain. Scientists think that all of this extra circuitry may affect brain size. Although autistic children are born with normal or smaller-than-normal brains, they undergo a period of rapid growth between ages 6 and 14 months, so that by about age four, their brains tends to be unusually large for their age.

Genetic defects in brain growth factors may lead to this abnormal brain development.

Neurobiological Concepts

Dopamine – a neurotransmitter released by the brain. It’s functions are involved withMovementMemoryPleasurable rewardBehaviour and cognitionAttentionSleepMoodLearning

Autistic individuals are thought to have increased levels of dopamine.

Mums health and ASD https://www.youtube.com/watch?v=kEdr-aGNQ8Y

Environemental impact https://www.youtube.com/watch?v=AXThkzrM78

Vitamin D https://www.youtube.com/watch?v=D4BsAALff4I

Research Task

Prenatal exposure to rubella Gestational diabetes Low birth weight Gluten - caused by a digestive disorder present from birth which causes gluten (present in wheat-derived foods) and casein (present in dairy products) to be converted to the opioid peptides.

ADHD

“minimal brain damage”

“minimal brain dysfunction”

“learning/behavioural disabilities”

“hyperactivity”

“hyperkinetic reaction of childhood”

Hyperkinetic reaction to Childhood

• 1968 - diagnostic and statistical manual of mental disorders DSM-II

• 1980 ADD – attention deficit disorder with or without hyperactivity introduced.

• 1987 refined to ADHD – attention deficit hyperactivity disorder

History of ADHD"An inattentive person won’t remark anything but will be shallow everywhere. He studies his matters only superficially; his judgements are erroneous and he misconceives the worth of things because he does not spend enough time and patience to search a matter individually or by the piece with the adequate accuracy. Such people only hear half of everything; they memorize or inform only half of it or do it in a messy manner. According to a proverb they generally know a little bit of all and nothing of the whole....They are mostly reckless, often copious considering imprudent projects, but they are also most inconstant in execution. They treat everything in a light manner since they are not attentive enough to feel denigration or disadvantages.“ 1775 - Der Philosophische Artz. Weikard's

History of ADHD

Weikard's recommended treatment was;

"The inattentive person is to be separated from the noise or any other objects; he is to be kept solitary, in the dark, when he is too active. The easily agile fibres are to be fixated by rubbing, cold baths, steel powder, Cinchona, mineral waters, horseback riding, and gymnastic exercises.“

Cinchona is a tree bark

History of ADHD

1902 – Sir George Frederick Still lectured at Royal College of Physicians on some “abnormal psychical conditions in children”.

He described 43 children who had serious problems with sustained attention and self-regulation, who were often aggressive, defiant, resistant to discipline, excessively emotional or passionate, which showed little inhibitory volition, and could not learn from the consequences of their actions; though their intellect was normal. He wrote "I would point out that a notable feature in many of these cases of moral defect without general impairment of intellect is a quite abnormal incapacity for sustained attention.

Causes of ADHDHunter v’s Farmer Hypothesis by Thom Hartmann

Thom Hartmann https://www.youtube.com/watch?v=kJ-Px2OmCJw

What do you think of Hartmann’s Hypothesis?

Genetic Causes of ADHD

• Strong evidence of genetic component – twin studies indicate a heritability factor of ~80%•Biederman (1990) reported a 57% risk to offspring if one parent has ADHD.• Predominant theory: Catecholamine (cat-a-co-l-mine) neurotransmitter dysfunction or imbalance •decreased dopamine and/or norepinephrine/ noradrenaline (stress hormone/chemical) uptake in brain - theory supported by positive response to stimulant treatment • Recent study indicates possible lack of serotonin as a factor in mice•Noro-pro-nef-rin

• Google Beiderman – locate Lancet – abstract of study

• 8–12% of children worldwide

Genetic Causes of ADHD

Dopamine genes - 3 different dopamine genes are implicated in causing ADHDLow cerebral dopamine release

DA type 2 geneDA transporter gene (DAT1)Dopamine receptor (DRD4, “repeater gene”) is over-represented in ADHD patients (strongest link to adhd)

News article – now being disputed

Brain Size and ADHDThe total brain size of children with ADHD is 3 – 4 % smaller than children without ADHD.

Children with more severe ADHD symptoms had smaller frontal lobes, temporal grey matter, caudate nucleus, and cerebellum.

The course of brain development in children with and without ADHD was similar. This suggests that changes in the brain happen early in development.

Kcl https://www.youtube.com/watch?v=4r3XWj269_g

Brain Structure and ADHD

A recent study using DTI (diffusion tensor imaging) found abnormalities in the fibre pathways in the frontal cortex, basal ganglia, brainstem, and cerebellum.White matter consists of axons (nerve fibres) covered by myelin sheaths

Research Task

Get your selves into 4 groups

Groups 1 and 2 try and found out how a smaller brain links into ADHD

Groups 3 and 4 find out why white matter matters in ADHD

Homework!A number of environmental factors have been linked to ADHD including;

Diet – food additives, sugar, omega 3 fatty acids

Exposure to organophosphate insecticides

Infections during pregnancy including measles, rubella, and streptococcal bacterial infection

I’d like each of you to research these links and decide which to include as part of your final essay.