Trastornos por consumo de sustancias y control de los impulsos Flashcards
QUESTION ONE
Your 16-year-old son is thrilled when he wins the 100-meter
dash in an important high school competition. This “natural high”
is most likely associated with inducing dopamine release in his
mesolimbic
pathway and in his:
A. Hypothalamus
B. Amygdala
C. Hippocampus
D. Cerebellum
E. Motor cortex
A, C, D, and E – Incorrect. These brain regions are not known to be
directly involved in the reactive reward system.
B – Correct. The brain can experience a “natural high” from activities
such as athletic or intellectual accomplishments. This occurs when
dopamine neurons release dopamine in the mesolimbic pathway,
which is sometimes known as the “pleasure center” of the brain,
and also in the amygdala, a critical component of the reactive
reward system, which conditions reward responses in association
with pleasurable activities.
QUESTION TWO
Impulsivity is hypothesized to be related to the _____, while compulsivity
is hypothesized to be related to the _____.
A. Amygdala, ventral striatum
B. Ventral striatum, amygdala
C. Dorsal striatum, ventral striatum
D. Ventral striatum, dorsal striatum
Impulsivity and compulsivity can perhaps be best differentiated by how
they both fail to control responses: impulsivity as the inability to stop
initiating actions, and compulsivity as the inability to terminate ongoing
actions. Impulsivity and compulsivity are hypothetically neurobiological
drives that are “bottom-up,” with impulsivity coming from the
ventral striatum, compulsivity coming from the dorsal striatum, and
different areas of the prefrontal cortex acting “top-down” to suppress
these drives.
A – Incorrect. The amygdala is involved in reward conditioning and
provides input to the striatum, but it is not directly associated with
impulsivity. The dorsal striatum, not the ventral striatum, is associated
with compulsivity.
B – Incorrect. Although the ventral striatum is linked to impulsivity,
the amygdala is not directly linked to compulsivity.
C – Incorrect. Impulsivity is hypothesized to be related to the ventral
striatum, while compulsivity is hypothesized to be related to the
dorsal striatum.
D – Correct. Impulsivity is hypothesized to be related to the ventral
striatum, while compulsivity is hypothesized to be related to the
dorsal striatum.
QUESTION THREE
Mark, a 35-year-old cigarette smoker, would like to quit but is
nervous because he typically craves a cigarette approximately every
2 hours. The craving and withdrawal are due to:
A. Desensitization of nicotinic receptors
B. Resensitization of nicotinic receptors
C. Desensitization of muscarinic receptors
D. Resensitization of muscarinic receptors
A – Incorrect. Cigarette smoking desensitizes all nicotinic alpha 4 beta
2 receptors and gets the maximum dopamine release. Receptors
become desensitized so that they cannot function temporarily,
and thus cannot react to either acetylcholine or nicotine. Putting
nicotinic receptors out of business by desensitizing them causes
neurons to attempt to overcome this lack of functioning receptors
by upregulating the number of receptors.
B – Correct. During cigarette smoking cessation, resensitized nicotinic
receptors no longer receiving nicotine are craving due to an
absence of dopamine release in the nucleus accumbens. Craving
seems to be initiated at the first sign of nicotinic receptor resensitization.
When the receptors resensitize to their resting state, this
initiates craving and withdrawal due to the lack of release of further
dopamine.
C and D – Incorrect. Cigarette smoking does not have an effect on
muscarinic receptors.
QUESTION FOUR
A 56-year-old man presents to a new primary care provider for a
routine physical exam. During the exam, he is asked some basic
screening questions about alcohol use. The patient states that he
drinks one mixed drink (containing a single 1-ounce shot) each
night. How would you assess this patient’s drinking behavior?
A. Low-risk drinking
B. At-risk drinking
C. Alcohol use disorder
Moderate alcohol consumption is defined as up to two drinks per day
for men and up to one drink per day for women. Heavy alcohol use
is defined as more than four drinks on any day for men or more than
three drinks for women.
For men under the age of 65, the recommended drinking limits are
no more than 4 drinks in one day and no more than 14 drinks in one
week. For men aged 65 and older and for women, the recommended
drinking limits are no more than three drinks per day and no more
than seven drinks per week. Amounts in excess of these would be considered
heavy or at-risk drinking but may not necessarily constitute an
alcohol use disorder.
A – Correct. This patient consumes seven drinks per week (one drink
per night). Therefore, he would be considered to have low-risk
drinking behavior.
B and C – Incorrect. Based on the recommended drinking limits, this
patient’s drinking behavior does not indicate at-risk drinking
or an alcohol use disorder.
QUESTION FIVE
Lisa, who is 13, has been staying up later than usual, complaining
that she can’t sleep. Sometimes during the day she locks herself
in her room for hours, only coming out to use the bathroom.
Recently, her mother discovered boxes of hidden cereal, chips, and
cookies in her closet. Her mother suspects that Lisa has an eating
disorder, but she is not sure if Lisa is vomiting or not, and her
weight appears to be normal. Upon psychiatric evaluation, Lisa has
negative affect, functional impairment, elevated thin-ideal internalization,
and body dissatisfaction. She says she is dieting, but that she
is not fasting. Which eating disorder is she at high risk for?
A. Anorexia nervosa
B. Bulimia nervosa
C. Binge eating disorder
A – Incorrect. Specific predictive risk factors for anorexia nervosa
(AN) include negative affect, functional impairment, and low body
mass index (BMI). However, youth who are inherently lean, rather
than purposely pursuing the thin ideal, are at risk for AN, thus
dieting would not be a specific risk factor for AN. Lisa does not
have a low BMI, suggesting that she is not at risk for AN.
B – Incorrect. Specific predictive risk factors for bulimia nervosa
include: thin-ideal internalization, positive thinness expectancy,
denial of thin-ideal costs, body dissatisfaction, dieting, negative
affect, overeating, fasting, functional impairment, and mental health
care. While Lisa suffers from negative affect, overeating, thin-ideal
internalization, body dissatisfaction, and functional impairment,
she is not fasting.
C – Correct. Specific predictive risk factors for binge eating disorder
(BED) include: elevated thin-ideal internalization, body dissatisfaction,
functional impairment, dieting, overeating, negative
affect, and mental health care. While negative affect and functional
impairment are risk factors for all eating disorders, since Lisa is
overeating and hiding her eating habits, while openly dieting, she
is at high risk for the development of BED.
QUESTION SIX
A 28-year-old painter presents with a severe drinking problem, and
you affirm the need for pharmacotherapy. When you suggest naltrexone,
he asks how this will help. Which might you use as part of
your explanation?
A. Naltrexone blocks mu-opioid receptors to reduce the euphoria
you might normally experience with heavy drinking
B. Naltrexone blocks metabotropic glutamate receptors (mGluR)
to reduce the euphoria you might normally experience with
heavy drinking
C. Naltrexone stimulates mu-opioid receptors to reduce the
euphoria you might normally experience with heavy drinking
D. Naltrexone stimulates mGluR receptors to reduce the euphoria
you might normally experience with heavy drinking
A – Correct. Blocking mu-opioid receptors might reduce the desire
to engage in heavy drinking activity, as doing so will be associated
with reduced reward.
B and D – Incorrect. Naltrexone is a mu-opioid antagonist. Mu-opioid
receptors theoretically contribute to the “high” or
euphoria experienced with heavy drinking, similar to their
function in opiate abuse.
C – Incorrect. Blocking mu-opioid receptors, not stimulating them, is
the likely mechanism of naltrexone’s efficacy.
QUESTION SEVEN
Sarah is a 24-year-old woman seeking treatment for opioid addiction.
To manage withdrawal, she is prescribed buprenorphine. The
addition of clonidine also functions to reduce the intensity of withdrawal
via what action?
A. Inhibition of norepinephrine reuptake
B. Inhibition of dopamine reuptake
C. Alpha 2A agonism
D. Alpha 2A antagonism
A, B, and D – Incorrect.
C – Correct. The intensity and duration of withdrawal from most
drugs, including opioids, are linked to drug half-life, with short
half-life full agonists such as morphine or heroin producing much
more intense and short-lasting withdrawal symptoms than either
long-acting methadone, which has a less intense but much longer
duration withdrawal, or buprenorphine, whose withdrawal is both
less intense and shorter. The intensity but not the duration of withdrawal
of both methadone and buprenorphine can be reduced by
the addition of an alpha 2A agonist such as clonidine or lofexidine.
These agents can reduce signs of autonomic hyperactivity during
withdrawal and aid in the detoxification process.
QUESTION EIGHT
A 39-year-old accountant you have been seeing for several years
has recently disclosed her 10-year prescription opiate addiction to
you. While she is quite functional, she continues to seek opiates in
order to avoid withdrawal effects. Which of the following is true
about her potential for recovery?
A. Opioid receptors can readapt to normal but need a reduction
in the amount of opiate exposure over time in order to do so
B. Opioid receptors cannot readapt to normal after severe addiction
but can reorganize to nearly full functionality with the aid
of permanent pharmacotherapy
A – Correct. The brain’s elasticity allows for opioid receptors to readapt
to normal after some time of abstinence from drug intake. This
may be difficult to tolerate, so reinstituting another opioid, such as
methadone, or a partial mu-opioid agonist, such as buprenorphine
(in combination with naloxone), may assist the detoxification process.
B – Incorrect.
QUESTION NINE
Mary is a 33-year-old woman with alcohol use disorder. She consumes
several drinks a day nearly every day of the week and has
recently had her two children removed from her care. She is motivated
to attempt to stop drinking in order to get her children back.
She previously attempted to quit cold turkey on her own, and
ended up in the emergency room with severe withdrawal symptoms.
Considering these factors, would she be a good candidate for
reduced-risk drinking as a goal?
A. Yes
B. No
A – Incorrect. Because this patient has a history of severe alcohol withdrawal
symptoms, she would not be a good candidate for reducedrisk
drinking as a goal. In addition, if she does not stop drinking it
is less likely that she will be able to have the children returned to
her care.
B – Correct. Reduced-risk drinking as a goal is controversial. However,
some patients will not agree to abstinence as a goal. For these
patients, it can still be beneficial to work with them to reduce
their drinking. Reduced-risk drinking may be a better goal for
patients with less severe problem drinking, including at-risk drinkers.
The strategy for achieving reduced-risk drinking for patients
with alcohol use disorder involves agreeing on a plan. Give patients
a choice in the goal if possible – this allows them to take part in
decisions affecting their lives and also gives them more responsibility
in the outcome. Some sample guidelines for reduced-risk
drinking include the “three As”: avoid having more than one drink
in one hour, avoid drinking patterns (same people, same places,
same time of day), and avoid drinking to deal with problems.
Contraindications for reduced-risk drinking (as opposed to abstinence)
include: existing conditions that would be exacerbated by
alcohol, use of disulfiram or other agents contraindicated with
alcohol, history of failed attempts with reduced-risk drinking,
pregnancy or breastfeeding, and a history of severe alcohol withdrawal
symptoms. For patients who should pursue abstinence but
refuse, one may try to have them agree to a trial period of abstinence
and a trial period of reduced-risk drinking; it can be beneficial
to use a written contract.
QUESTION TEN
Clara is at a party with some friends and decides to try “Molly.” She
was told that “Molly” is the pure form of ecstasy (3,4-methylenedioxymethamphetamine
[MDMA]), lacking many of the harmful
additives that can be found in ecstasy. Upon taking the pill, Clara
notices that while she is in a state of excited delirium she has a
nosebleed, sweats profusely, and feels nauseated. She is disoriented
and wonders why she is feeling so horrible after taking the pure
form of the drug. Her symptoms are most likely attributed to:
A. A synthetic cathinone, such as methylone
B. Caffeine
C. Methamphetamine
A – Correct. While “Molly” is the pure crystal powder form of MDMA,
and lacks harmful additives commonly found in MDMA, such
as caffeine and methamphetamine, the compounds are replaced
by dangerous synthetic cathinones, such as methylone. Synthetic
cathinones can cause nosebleeds, paranoia, hallucinations, nausea,
sweating, panic attacks, and even death.
B, C – Incorrect.
QUESTION ELEVEN
Peter is a 17-year-old student who has been using spice (synthetic
cannabinoid) over the past year. Synthetic cannabinoids such as
spice may be associated with an increased risk of psychosis compared
to natural marijuana because they:
A. Do not contain cannabidiol
B. Are full rather than partial agonists
C. A and B
D. Neither A nor B
A – Partially correct. Spice use may cause recurrence or exacerbation
of preexisting psychotic symptoms, with studies suggesting a possible
three times increased risk of subsequent psychosis. One factor
that may explain why this is seen with spice but not generally with
natural marijuana is that natural marijuana contains cannabidiol,
which is thought to have antipsychotic properties. In contrast, synthetic
cannabinoids do not contain cannabidiol.
B – Partially correct. Unlike natural marijuana, which is a partial agonist
at the cannabinoid 1 (CB-1) receptor, synthetic cannabinoids
are full agonists at CB-1. Therefore, they can potentially lead to
excessive stimulation of the receptor. In addition, synthetic cannabinoids
bind to the CB-1 receptor with 800 times greater affinity
than natural marijuana.
C – Correct. Both A and B are correct.
D – Incorrect.
QUESTION TWELVE
Eddie is a 43-year-old man who has a 22-year-old daughter with
a history of cocaine addiction. He recently heard about a novel
cocaine vaccine that is being studied and would like to know more
about it. In describing the cocaine vaccine, you explain that a
cocaine-induced “high” is experienced when:
A. At least 47% of dopamine transporters are occupied by cocaine
B. At least 97% of norepinephrine transporters are occupied by
cocaine
C. Both of the above
A – Correct. Studies have shown that the “high” associated with
cocaine occurs when at least 47% of dopamine transporters in
the brain are occupied by cocaine. When the cocaine vaccine is
administered, it causes the production of antibodies that then bind
to the vaccine. The antibodies produced in response to the vaccine
do not cross into the brain; thus, antibody-bound cocaine
remains in the periphery and may therefore reduce the percentage
of cocaine-occupied dopamine transporters below the 47%
threshold needed to induce a high. One potential advantage of the
vaccine is that it prevents cocaine from entering the brain without
affecting normal dopamine neurotransmission.
B – Incorrect. Although cocaine does bind to the norepinephrine
transporter, it is the effects at the dopamine transporter that are
primarily responsible for the induced high.
C – Incorrect.
QUESTION THIRTEEN
A 26-year-old woman develops a dependence on opioids after taking
them during her recovery from knee surgery. She attempts to
stop using them on her own, but when she does stop or decreases
her dose, she experiences nausea, muscle aches, sweating, diarrhea,
insomnia, and depression. She and her practitioner decide that
buprenorphine would be an appropriate treatment strategy. Which
of the following is true?
A. The patient should have the buprenorphine implant Probuphine
inserted immediately
B. The patient should initiate oral buprenorphine while down-titrating
her current opioid
C. The patient should be in a mild withdrawal state prior to initiating
buprenorphine
D. The patient should complete withdrawal before beginning
buprenorphine treatment
A – Incorrect. The implant Probuphine contains buprenorphine, a partial
opioid agonist. Probuphine is indicated for the maintenance
treatment of opioid dependence in patients who have achieved
and sustained prolonged clinical stability on low to moderate doses
of a transmucosal buprenorphine-containing product (i.e., doses of
no more than 8 mg/day of a sublingual tablet). Probuphine is not
appropriate for new entrants to treatment and patients who have
not achieved and sustained prolonged clinical stability, while being
maintained on buprenorphine sublingual 8 mg/day.
B – Incorrect. Buprenorphine is a partial opioid agonist. It has stronger
affinity for the mu-opioid receptor than other opioids, and thus
causes immediate withdrawal if not administered when the patient
is already in withdrawal.
C – Correct. Buprenorphine is a partial opioid agonist. It has stronger
affinity for the mu-opioid receptor than other opioids, and thus
causes immediate withdrawal if not administered when the patient
is already in withdrawal. If the patient is already experiencing
withdrawal, however, it will relieve those symptoms. Buprenorphine
is commonly combined with naloxone in order to reduce
its diversion and intravenous abuse.
D – Incorrect.
QUESTION FOURTEEN
A 23-year-old woman has recently been diagnosed with binge eating
disorder. Since the age of 16 she has had episodes where she
eats far beyond the point of hunger, typically at night and when
she is alone. The patient feels very guilty and disgusted with herself
about her eating habits; this is reinforced by her family members,
who tell her that she is just weak and should have more self-control.
Is there evidence to support the idea that individuals can develop
an addiction to food?
A. Yes
B. No
A – Correct. Food has powerful reinforcing effects. The neurobiological
basis of eating and appetite is linked not just to the hypothalamus,
but also to the connections that hypothalamic circuits
make to reward pathways. Following food deprivation, any food
will activate reward pathways. However, palatable (i.e., high-fat,
high-sugar) foods activate reward pathways more reliably and more
potently than do unpalatable foods. Even without food deprivation,
highly palatable foods will activate the release of endocannabinoids
and ghrelin; this is not true of unpalatable foods.
There is also evidence that the neurobiological changes associated
with the progression to compulsive drug use may similarly occur
in individuals with compulsive eating behaviors. When exposed to
food cues, obese individuals exhibit increased activation, compared
to lean individuals, in regions that process palatability. In contrast,
obese individuals exhibit decreased activation of reward circuits
during actual food consumption. This is analogous to cravings and
tolerance in patients with substance use disorders.
Of course, not everyone who is obese has an eating compulsion,
since obesity is also related to genetics and to lifestyle factors such
as exercise, caloric intake, and the specific content of consumed
foods. In fact, studies of brain activation in response to images of
food can differentiate between individuals with binge eating disorder
and overweight controls; in particular, differences in activation
have been noted in the right ventral striatum.
B – Incorrect.
QUESTION FIFTEEN
Evan is a 27-year-old male suffering from posttraumatic stress
disorder. He is undergoing 3,4-methylenedioxymethamphetamine
(MDMA [“ecstasy”])-assisted psychotherapy to induce an
empathic and safe psychological state to explore his painful traumatic
memories in the presence of his therapist. MDMA is able to
induce this psychological state primarily through which action?
A. Serotonin 1A partial agonism
B. Serotonin 2A agonism
C. Competitive inhibition of the dopamine
transporter
D. Competitive inhibition of the serotonin transporter
A – Incorrect. MDMA does not target serotonin 1A partial agonism.
B – Incorrect. MDMA does not target serotonin 2A agonism.
C – Incorrect. MDMA does not target competitive inhibition of the
dopamine transporter.
D – Correct. MDMA targets the serotonin transporter as a competitive
inhibitor and pseudosubstrate, binding at the same site where serotonin
binds to this transporter, thus inhibiting serotonin reuptake.
Once there in sufficient quantities, MDMA is also a competitive
inhibitor of the vesicular transporter (VMAT2) for serotonin.
MDMA displaces serotonin from the synaptic vesicles, causing
serotonin release from synaptic vesicles into the cytoplasm presynaptically.
Once in the synapse, the serotonin can play upon any
serotonin receptors that are there, but the evidence suggests that
this is mostly upon 5HT2A receptors, just like the hallucinogen.
