Lecture 23: Psychological Disorders lll Flashcards
ocd is characterized by
obsessions and compulsions
Obsessions
repeatedly having certain thoughts
Compulsions
a need to repeatedly check things or repeatedly perform certain routines to an extent that it causes distress & impairs general functioning
4 groups of ocd symptoms
Symmetry, cleaning, hoarding, forbidden thoughts
prevalence of ocd
affects ~1% of the population
prevalence in ocd in men vs. women
Slightly more prevalent in women. Diagnosis is typically earlier in men: occurs in adulthood for women but in adolescence for men
when do ocd symptoms typically start?
before age 25 in both sexes
do adults with ocd understand that their behaviours are abnormal?
Most adults with OCD realize that their behaviours don’t make sense but feel the need to act as though they do
causes of ocd are
genetic and environmental
what % variability do gene variations account for in ocd
50% of the variability
ocd is associated with damage to ____
the loop in the frontal lobe between the PFC and the basal ganglia
treatment for ocd
a version of CBT called exposure and response prevention
exposure and response prevention
Involves increasing exposure to what causes the problems while not allowing the repetitive behaviour to occur
do pharmacological approaches work for ocd?
sometimes ssris are used, but usually exposure and response prevention is better
ocd can appear after damage to what brain regions
the basal ganglia, cingulate gyrus, or PFC
ocd is associated with increased activity in what brain region
the frontal lobes and striatum
cingulotomy
the cutting of a fibre bundle between the PFC and the anterior cingulate cortex
cingulotomy is used for what condition
ocd
adhd
A mental disorder characterized by problems paying attention, hyperactivity, or difficulty controlling behaviour in an age-appropriate manner
what % of North American children are being treated for adhd
More than 5%
when do adhd symptoms appear?
before age 12
symptoms of adhd
Reckless and impetuous behaviour
Acting without reflecting
Being distracted by interfering activities while performing an ongoing task
Difficulty withholding a response
adhd in boys vs girls
Boys are diagnosed 3x more than girls
comorbidity of adhd
Often associated with aggression, conduct disorder, learning disabilities, depression, anxiety, and low self-esteem
estimated heritability for adhd
ranges from 75-91%
both ocd & adhd are associated with
previous infections or brain trauma
what prenatal factors are associated with adhd
Drug and alcohol use and infections during pregnancy, and low birth weight,
treatment of adhd
Typically involves counselling and medications
what medication is used for adhd & how do they work
stimulants that raise dopamine levels by blocking or reversing the dopamine reuptake transporter. Raising the average dopamine levels in the brain increases the value of the current environment and makes a task more interesting than it otherwise would be
what brain structure is responsible for the amount of effort people are willing to exert
basal dopamine levels
stress
the physiological reaction caused by the perception of aversive or threatening situations
what part of the nervous system does stress activate?
the sympathetic branch of the autonomic nervous system. it also activates the adrenal glands to release hormones into the blood, including epinephrine, norepinephrine, and glucocorticoids such as cortisol
Glucocorticoids
A group of hormones (corticosteroids) that are important in protein and carbohydrate metabolism, secreted especially in times of stress. Help to break down and convert proteins into glucose, make fats available for energy, increase blood flow, suppress the secretion of sex hormones, and stimulate behavioural responses
Cortisol
A specific glucocorticoid secreted by the adrenal cortex in response to stress
what brain structure controls the release of glucocorticoids
the hypothalamus
steps of glucocorticoid secretion
- In response to stress, the hypothalamus starts a chain of events by releasing CRH/CRF (corticotropin-releasing hormone/factor)
- CRH stimulates the pituitary to secrete ACTH (adrenocorticotropic hormone)
- ACTH stimulates the adrenal glands to promote glucocorticoids
long term effects of glucocorticoids include
Increased blood pressure
Damage to muscle tissue
Steroid diabetes
Infertility
Inhibition of growth
Inhibition of the inflammatory responses
Suppression of the immune system
stress during 3-5 day periods before showing symptoms of upper respiratory infection
people experienced an increased number of undesirable, stressful events
stress in monkeys at the bottom of the social hierarchy
are almost continually stressed. They seem to die more often from stress-related issues including gastric ulcers, enlarged adrenal glands, and damaged hippocampi
ptsd
A mental disorder that can develop after a person is exposed to a traumatic event
symptoms of ptsd
include disturbing thoughts, feelings, or dreams related to the event, mental or physical distress to trauma-related cues and efforts to avoid them and an increase in the fight-or-flight response
do most people who experience tramatic events get ptsd
no
ptsd and multiple traumatic events
The likelihood of developing PTSD increases with the number of traumatic events a person has experienced
genetic variance and ptsd
Genetics cause 30% of the variance in PTSD
treatment of ptsd
CBT, group therapy and medication (SSRIs)
neurobiological basis for ptsd
associated. with abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis, which coordinates hormonal response to stress. greater activity in the amygdala and less activation in the pfc
when does alcoholism begin
Alcoholism often begins in one’s 20s with daily use that gradually increases over decades
problems associated with alcohol abuse
Automobile accidents
Fetal alcohol syndrome
Cirrhosis of the liver
Korsakoff’s syndrome
Increased rate of heart disease
Increased rate of intracerebral hemorrhage
Pancreatitis and diabetes
genetic factors and alcoholism
account for 40-60% of risk factors
Reinforcement
drugs that lead to dependency must first reinforce people’s behaviour
reinforcement is always
context-dependent
when is the effect of reinforcement greatest?
if it occurs immediately after a response occurs
what explains the relative addictive potential of different drugs
The speed that the brain perceives reinforcement
what is the neurobiological mechanism of most addictive drugs?
elicit dopamine release in the striatum, particularly in the nucleus accumbens
aversive stimuli and dopamine release
Aversive stimuli can also trigger the release of dopamine and some areas of the nucleus accumbens seem to promote avoidance behaviours
tolerance
the fact that increasingly large doses of drugs must be taken to achieve a particular effect. Caused by compensatory mechanisms that oppose the effect of the drug. Not all addictive drugs produce tolerance and withdrawal
withdrawal symptoms
the appearance of symptoms opposite to those produced by the drug when it is suddenly no longer taken. Caused by the presence of compensatory mechanisms that relate to drug tolerance.
positive reinforcement
addition of a pleasurable stimulus that is contingent on a particular response
negative reinforcement
removal or reduction of an aversive stimulus that is contingent on a particular response, with an attendant increase in the frequency of that response
the theory that drug addiction was due to a fear of withdrawal is a type of
negative reinforcement
people with a history of drug use show deficits in what brain area? (& what do these deficits cause)
the pfc. these deficits make people less able to maintain self-control
comorbidity of addiction
high level of comorbidity of schizophrenia, ADHD, and substance abuse
3 approaches to treating addiction
- The binding site blocker approach (ex. Naltrexone)
- The maintenance approach (ex. Methadone maintenance)
- The partial agonist approach (ex. Buprenorphine)
Naltrexone
a somewhat long-acting, slow-onset opioid receptor antagonist that is prescribed to alcoholics and opiate addicts. It reduces the high produced by opiates because opiates can’t bind to the receptor, but it also tends to reduce drug, alcohol, and food cravings in certain people
Naloxone (Narcan)
extremely rapid and short-lived opioid receptor antagonist that reverses the effects of an opiate overdose. During an opiate overdose, people can lose consciousness and stop breathing. A naloxone injection can immediately reverse these effects and even elicit withdrawal symptoms
Methadone maintenance
Potent opiate, similar to morphine or heroin, but with a slower onset and offset. Methadone maintenance programs administer the drug to their patients in liquid form, which they must drink in the presence of supervising personnel.
Buprenorphine
a very high affinity partial opioid receptor agonist. It strongly binds to opioid receptors but produces only a weak effect when blocking the effect of other opioids. To reduce the potential for abuse, it is commonly mixed with naloxone
Varenicline
a partial agonist at nicotinic (acetylcholine receptors) that is approved to treat nicotine addiction
