Lecture 22: Psychological Disorders ll Flashcards
autism
Describes a wide range of developmental disorders that are characterized by troubles with social interaction and communication, and by restricted and repetitive behaviour
autism incidence
around 1% of the population
when do autism symptoms typically appear?
Parents usually notice symptoms during the first 2-3 years of a child’s life
what are the first symptoms of autism to appear?
Social impairments
causes of autism
combination of environmental and genetic factors
heritability of autism
70%
heritability of autism spectrum disorder
90%
autism and genes
Many cases have been linked to rare gene mutations. These include chromosome abnormalities involving deletions, duplications, or inversions of genetic material. Other cases are associated with multigene interactions across common gene variants.
maternal health and autism
Some cases have been linked with maternal viral infection during pregnancy
prevalence of speech in people with autism
⅓ of people with Autism do not develop enough natural speech to meet their daily communication needs
Asperger’s syndrome
Mild forms of Autism that mostly involve deficient or absent social interactions and repetitive and stereotyped behaviours along with obsessional interest in narrow subjects
autism in males vs. females
Autism is 4x more common in males than females. If only cases with intellectual disability are considered, the ratio is 2:1. If only cases of high-functioning autism are considered, the ratio is 7:1
hypothesis for why autism is more prevalent in males
Within species, the heterogametic (males in humans, females in birds, butterflies, some reptiles and fish) shows slightly more variability on all kinds of traits
brain development and autism
Smaller brain at birth, but grows abnormally fast and by 2-3 years is about 10% larger than a normal brain. Then, the growth of an autistic brain slows down and by adolescence is only about 1-2% larger than normal
hypothesis for differing brain activity in people with autism
Altered neuronal migration during early gestation
Abnormal formation of synapses and dendritic spines
Overconnectivity of key brain areas
Unbalanced excitatory-inhibitory neural networks
fusiform area & autism
There is little or no activity in the fusiform face area of autistic adults looking at pictures of human faces.
goal of autism treatment
lessen the impact of the associative deficits & family distress and increase quality of life & independence
medications used for autism
Anticonvulsants
Antidepressants
Antipsychotics
Stimulants
anticonvulsants
↑ GABA receptor activity
antidepressants
↑ serotonin receptor activity
antipsychotics
↓ dopamine receptor activity
stimulants
↑ dopamine receptor activity
affect
feelings and emotions
mood (affective) disorder
serious mood disorder
types of mood disorders
Bipolar disorder and Major Depressive Disorder (MDD)
bipolar disorder
Serious mood disorder characterized by cyclical periods of mania and depression
bipolar disorder prevalence
1% of the population
heritability of bipolar disorder
~80% of the risk is attributed to genetics.
major depressive disorder
Serious mood disorder that consists of unremitting depression or periods of depression
major depressive disorder prevalence
7% in women and 3% in men
heritability of mdd
~40%
mania
Characterized by a sense of euphoria that does not seem to be justified by circumstances. Usually, exhibit nonstop speech and motor activity
treatment for bipolar disorder
lithium salts (for manic phase) and anticonvulsants. Once mania is eliminated, depression usually doesn’t follow
tricyclic antidepressants
inhibits reuptake of serotonin and norepinephrine but also affects other neurotransmitters
Serotonin specific reuptake inhibitors (SSRIs)
A class of drugs that specifically inhibit the reuptake of serotonin without affecting the reuptake of other neurotransmitters. The most common one is Prozac (fluoxetine). Similar drugs are Celexa, Paxil, Zoloft, etc…
Serotonin and norepinephrine reuptake inhibitor (SNRI)
Antidepressant drug that specifically inhibits reuptake of norepinephrine and serotonin without affecting reuptake of other neurotransmitters
treatments for depression include
- Drugs that increase serotonin and/or norepinephrine signalling by inhibiting their enzymatic breakdown (e.g., monoamine oxidase inhibitors, MAOi)
- Drugs that increase serotonin and/or norepinephrine by blocking their reuptake (e.g., tricyclics and serotonin specific reuptake inhibitors, SSRIs).
- Ketamine (NMDA glutamate receptor blocker)
- Electroconvulsive therapy (ECT)
- Deep brain stimulation
- Transcranial magnetic stimulation
- Vagus nerve stimulation
- Bright-light therapy (phototherapy)
- Sleep deprivation
monoamines
Serotonin, Norephipherine, Dopamine
monoamine hypothesis
States that depression is caused by insufficient monoamine receptor activity
what monoamines are of most interest to researchers?
serotonin and norepinephrine because symptoms of depression are generally not relieved by potent dopamine receptor agonists such as amphetamine or cocaine
tryptophan
The molecular precursor to serotonin
tryptophan and depression
Giving people a low-tryptophan diet, then a tryptophan-free amino acid cocktail lowers brain tryptophan levels and decreases the synthesis of serotonin (5-HT)
tryptophan depletion in people susceptible to depression
can elicit a depressive episode
SSRIs and SSNIs onset
increase the levels of 5-HT and norepinephrine in the brain very rapidly, but they don’t relieve symptoms of depression until they have been taken for several weeks. Something other than a simple increase in monoamine receptor activity is responsible for the normalization of mood
anterior cingulate cortex and depression
One area of the anterior cingulate cortex (the subgenual region known as area 25) becomes less active after successful depression treatments
where is deep brain stimulation for depression performed
in the subgenual anterior cingulate cortex and in the nucleus accumbens
what are new promising approaches to treating depression
transcranial magnetic stimulation (TMS) directed to areas of the PFC or vagal nerve stimulation (VNS)
electroconvulsive therapy
Seizures are electrically induced by applying brief electrical shocks to the head. Used to treat severe depression and bipolar disorder. reduces symptoms within days
characteristics of sleep in people with depression
- Shallow, fragmented sleep
- Awaken frequently, especially in the morning
- Spend more time in stage 1 sleep
- Spend less time in stage 3-4 sleep
- Enter REM sleep soon after falling asleep
total sleep deprivation
has an immediate antidepressant effect. Depression returns after a normal night’s sleep. This suggests that a chemical builds up during waking hours that has some antidepressant effect and it gets cleared away during sleep
rem sleep deprivation
also works, although more slowly, over the course of several weeks (similar to SSRIs)
anxiety disorder
A variety of psychological disorders characterized by unrealistic and unfounded fear and anxiety. Includes muscle tension, over activity of the autonomic nervous system, expectation of an impending disaster, and continuous vigilance for danger
generalized anxiety disorder
Disorder characterized by excessive anxiety and worry serious enough to cause disruption of their lives
social anxiety disorder
Disorder characterized by excessive fear of being exposed to the scrutiny of other people that leads to avoidance of social situations in which person is called on to perform
panic disorder
Disorder characterized by episodic periods of severe and unremitting terror. Includes symptoms such as shortness of breath, irregularities in heartbeat, and other autonomic symptoms, accompanied by intense fear
anticipatory anxiety
Fear of having a panic attack promotes anticipatory anxiety that sometimes leads to the development of agoraphobia
agoraphobia
Fear of being away from home or other protected places
comorbidity of anxiety disorders
People often have more than one type of anxiety disorder.
prevalence of anxiety disorders
In a given year, about 12% of people are affected by anxiety disorder
females vs. males anxiety disorders
appears twice as often in females as males
age of anxiety onset
generally begins before the age of 25.
prevalence of phobias
12% of people will develop a specific phobia
prevalence of social anxiety disorder
10% will develop social anxiety disorder at some point in their life
anxiety disorders causes
Combination of genetic and environmental factors
anxiety disorder and dementia
Older people with dementia often have anxiety disorders
what brain structures are involved in anxiety?
the amygdala and prefrontal cortex are involved in anxiety disorders
adolescents with anxiety and angry faces
showed increased activation of the amygdala and decreased activation of the ventrolateral prefrontal cortex while looking at angry faces
amygdala activity in anxious college students
is increased
treatment for anxiety disorders
- lifestyle changes
- cbt
- medications
medications for anxiety disorders
- benzos sometimes used, particularly in emergency settings because of their rapid onset
- ssris are frequently used as a first-line treatment
