Bio Psych Exam #3 Flashcards
Psychopharmacology
the study of drugs that affect the nervous system and behavior
What is a drug?
An exogenous (made outside of the body) chemical not necessary for normal cellular functioning that significantly alters the functions of certain cells of the body when taken in relatively low doses
(exogenous, low doses, not necessary
Drugs and behavior
The changes a drug produces in an animal’s physiological processes and behavior
- Ex: morphine/heroine and other opioids are pain relievers
Drugs have sites of action
each drug has a unique effect and a site of action
**Ex: there are specialized receptors for opioids; when molecules of heroin activate these opioid receptors the activity of the neuron changes
Pharmacokinetics
what the body does with the drug
Absorption types
1) Intravenous (IV) injection - into a vein
2) Intraperitoneal (IP) injection - into space surrounding stomach, liver → usually in animals
3) Intramuscular injection (IM_: vaccines
4) Subcutaneous injection (SC) = into the space beneath the skin
5) Orally = swallow pill
Sublingual - under the 6)tongue
7) Inhalation - smoked
8) Intranasal - snort
9) Topical - into skin
Cocaine absorption
1) IV: strong high immediately
2) smoking: similar to IV, less higher
3) snorting: takes a bit to kick in, less high but lasts longer
4) oral: takes an hour to kick in, less high but lasts very long
Oral dose vs. Sublingual
1) Oral: Has to go through many steps to get to the brain
2) Sublingual: under the tongue
- Dissolve and can get into the blood system immediately: travel through the capillaries in your mouth
Goes to the brain almost immediately
Distribution of drugs within the body
After absorption, the drug distributes to interstitial and intracellular fluids → depends on some physiological factors and physicochemical properties
Body parts with high drug distribution
The liver, kidneys, brain, and other well-irrigated (have the most blood supply) organs receive most of the drug
Body parts with low drug distribution
Release to muscles, most viscera, and adipose tissue (fat) is slower
What prevents drugs from getting to the brain?
- Blood-brain barrier: a barrier that restricts the indiscriminate access of certain substances in the bloodstream to the CNS
- A layer of astrocytes that prevents substances in the circulating blood from freely entering the extracellular fluid of the brain
lack of blood brain barrier in:
1) Pituitary gland
2) Pineal gland (day/night cycle) → drugs can easily impact sleep
3) Area postrema (vomit toxic substances): in the brain stem
Metabolism
Set of reactions and transformations that drugs undergo in the body
Excretion
Elimination by the body of residues of drug metabolism
Kidney and excretion
Take blood and filter out waste products
**most important excretory organ
Excretion pathways
1) Renal (kidneys)
2) Biliary (bile) and fecal (poop)
3) Pulmonary (lungs)
4) Sweat, saliva, and tears
5) Breast milk
Dose response curve
Systematically titrate the dose of the drug: see what the effect of the drug is at each dose
Left: The dose is too low to have any therapeutic benefit
Right: point where the dose plateaus → If you give the patient a larger dose, the therapeutic benefit does not increase
The margin of safety on a dose response curve
1) The effective dose (orange)
2) Where it becomes lethal (purple) → opioids will stop respiration
Tolerance
A decrease in the effectiveness of a drug administered repeatedly
- Once someone has developed tolerance, they will likely show withdrawal symptoms
- Decrease in effectiveness of binding, **receptors become less sensitive or receptors decrease in overall numbers
Sensitization
An increase in the effectiveness of a drug that is administered repeatedly
Less common than tolerance
Can get both tolerance and sensitization
Example of sensitization and tolerance
Example: movement effects of cocaine show sensitization → repeated use leads to movement disorders./convulsions whereas euphoric effects don’t show sensitization, maybe even tolerance
Can develop tolerance to the euphoria
Can develop sensitization for movement disorders
Agonists
A drug that mimics or facilitates the effects of a neurotransmitter on the postsynaptic cell
- a drug that helps the system
Birth of agonists
some neurotransmitters need raw/precursor materials
*If we administer more of the precursor, we get more neurotransmitters → our effects are enhanced
Antagonists
A drug that opposes or inhibits the neurotransmitter on the postsynaptic cell – harms the system
Antagonist birth
Birth: some of the synthesizing steps are controlled by enzymes
*if we neutralize the enzymes with a drug, it prevents the neurotransmitter from being produced (effects blocked)
Competitive binding
only one spot (for drug or neurotransmitter)
- Direct agonis or Direct antagonist
Noncompetitive binding
It is possible for NT to bind to one part and the drug to bind to another part
- Indirect agonist or Inverse agonist
Psychotropic
drugs that impact behavior
1) Antidepressants:
used to lift mood out of a depressive episode
Antidepressants treat
Depression (mainly)
Anxiety disorders
OCD
Panic disorders
Phobias
Bulimia
PTSD
Neurotransmitters involved in mood disorders
Dopamine
Noradrenaline
Serotonin
Mood disorders
symptomatic issues in people’s affect
Symptoms of mood disorders
1) Reduction in positive affect: loss of happiness, loss of interest less and/or energy (nor and dop affected)
2) Increase in negative affect: more depressed mood, more guilt, more anxiety, etc. (nor and serotonin affected)
Types of antidepressants
1) Selective serotonin reuptake inhibitors (SSRIs)
2) Serotonin-norepinephrine reuptake inhibitors (SNRIs)
3) Norepinephrine and dopamine reuptake inhibitors (NDRIs)
4) Tricyclics: not used anymore due to side effects / MAOs
mood stabilizers:
regulate mood so it doesn’t get too low (depression) or too high (mania)
Types of mood stablizers
Lithium:
Mechanism of action not known
Effective for manic episodes and maintaining remission
Helpful for suicide prevention
Anticonvulsants (anti-epileptic):
Uncertain mechanisms of action (might act on GABA)
Effective for acute manic phases of bipolar disorders
Inconclusive for bipolar depression
Many side effects (exhaustion)
anti-anxiety medications
high overlap with depression
SSRI and SNRI
Anticonvulsants
Benzodiazepines
Benzodiazepines
Depressants and sedatives → feelings of calm drowsiness, GABA agonists
Inhibits the arousal system
People tolerate well but risk of dependence, abuse, and withdrawal reactions
Examples: Xanax, Valium, Ativan
** do not combine with alcohol
Benzodiazepines and alchol
Chloride channel: when GABA binds, it opens the channel; why it is inhibitory (lets more negative in)
Alcohol increases GABA binding → chloride channel open for longer
Noncompetitive binding: Benzodiazepines can bind and open the channel even more
Effects summate (level up)
stimulants
Usually used to treat ADHD and some sleep disorders
Types of stimulants
Amphetamines
Adderall: blocks the reuptake of norepinephrine and dopamine
Ritalin: non-competitively blocks the reuptake of dopamine and noradrenaline
Major potential for abuse
**do not combine with alcohol
typical antipsychotics
First generation → 1950s
Generally, they are blocking dopamine at D2 receptors → tight binding
Useful but prescribed out of desperation → high risk of side effects
Ex: Haldol and Thorazine
Psychosis
a condition where people lose touch with reality
- Hard to tell what is real and what is not
Delusions and hallucinations
Atypical antipsychotics:
Second generation (1990s)
Also blocking dopamine at D2 receptors → use loose binding (not as stuck into the receptor)
Very useful
Side effects are not as bad as typical antipsychotics
Ex: Risperdal, Olanzapine
Order of operations: what should be treated first?
1)alcohol/stimulant/substance abuse
2) mood disorders
3) anxiety disorders
4) ADHD
5) nicotine dependence
Substance abuse disorder
The compulsion to seek out and take the drug
Impaired control in limiting intake (can not stick to having “just one”)
Persistent despite very clear evidence of overtly harmful consequences
Progressive neglect of alternative pleasures or interests
Relapse → not required for substance use disorder but common
Positive reinforcement
something good is added
A positive consequence will increase behavior
Ex: rapid euphoria after taking a drug will increase drug-taking behavior
Neural mechanism of positive reinforcement
Synaptic strengthening in the ventral tegmental area (green pathway is strengthened)
VTA: sits next to SN → also dopaminergic
Mesolimbic pathway (from VTA to the ventral striatum (aka nucleus accumbens))
**Ventral striatum (nucleus accumbens) → inital stages of addiction behaviors
Dorsal striatum (caudate + putamen): habit-formation; cue induced
Negative reinforcement
A response/behavior is strengthened when you remove/avoid the aversive thing
Ex: feeling of alleviated pain after drug taking will increase drug-taking behavior
Incentive-sensitization theory of substance abuse
Wanting and liking are different and mediated by different brain circuitry
- wanting: based on cues from the environment, becomes hyperactive over time (compulsive)
- liking: actual pleasurable impact of the reward consumption
Neural pathways of wanting and liking
Striatum (midbrain) to nucleus accumbens
White: liking pathway
Gray: wanting pathway
Risk factors of addiction
Age: older adults more likely to abuse certain styles of drugs
Genetics
Environment:
- Adverse childhood experiences (ACEs)
Neurological disorders definition
diseases of the central and peripheral nervous system
Mental disorder
generally characterized by a combination of abnormal thoughts, perceptions, emotions, behavior, and relationships with others
Psychiatrist
able to conduct psychotherapy and prescribe medications and other medical treatments
Psychologist
often has extensive training in research or clinical practice
Psychologists treat mental disorders with psychotherapy and some specialize in psychological testing and evaluation
Research PhD
DSM
Lists symptom checklists for many disorders → have to see where your symptoms cluster as there is no physiological test for a disorder
What you need for a mental health disorder diagnosis
Impairment of functioning that impacts quality of life
Duration → needs to be persistent
Pros of the symptom checklist approach
Measures the invisible
Standardization
Can help rule things out
Cons of the symptom checklist approach
Wrong way of measuring?
Different clinical presentation earns the same diagnosis → depression can be different for everyone
Is it helpful for understanding?
History of depression
-not a diagnosis until the early 1900s
-1930s: benzine was marketed as a treatment for fatigue and mild depression-like symptoms (not depression)
-1940s: ECT to treat depression, don’t know why it works but it is effective
1950s: drugs for anxiety came out but they didn’t really help with depression
Late 1950s: first drugs that do seem to treat depression (meant to treat tuberculosis)
Serotonin hypothesis of depression
If we block the reuptake of MAO and people get happier, there must be low levels of these neurotransmitters in people with depression
Is the serotonin hypothesis of depression correct?
**NO evidence to suggest that low levels of neurotransmitters cause depression → These drugs do help but this is not the root cause
Neurotrophic
related to the growth/survival of neurons
Neurotrophic hypothesis
**depression is caused by low lebels of neurotrophins (BDNF) which leads to neuronal loss
increased 5-HT (serotonin) and NE activity at certain synapses → leads to important downstream actions that may underlie the observed antidepressant effects
**metabatropic receptors: downregulation of post synaptic receptor
Downregulation
decreased response and/or decreased number of or sensitivity of receptors