Drugs of Abuse and substance use disorder

Question 1

All drugs that have significant dependence potential have what shared quality?

Answer 1

• They all share the pharmacologic property of enhancing dopamine activity in the nucleus accumbens
  
  • They can do this directly or indirectly through several NT systems
  • Stimulation of release, block of reuptake, inhibition of inhibitory pathways
  • Think of all roads converging on the Nac, you don’t care as much about it’s outputs, but think about what the drug does to the Nac inputs

Question 2

Describe the different “facets” of drug toxicity.

Answer 2

• Drug toxicity can be from too high a concentration of drug from a single dose, or it can be thought of as an accumulation from chronic use/abuse
  
  • Also, there are phsyiological and psycholigical symptoms that both point to toxicity
  • Toxicity is inevitable to some level in chronic use

Question 3

What are the 5 different tolerance mechanisms?

Answer 3

• Metabolic
○ The body metabolizes the drug faster
• Pharmacodynamic
○ The same concentration doesn’t have the same effect
○ Receptor sensitivity most often
• Learned
○ Behavioral coping skills that allow a person to function under mild-moderate intoxication
• Reverse
○ Think of this as developing craving
○ Nac is sensitized to the drug effect following repeated doses
• Cross
○ Tolerance to one drug is shared with other drugs of a similar class or mechanism
○ Can use this to your advantage during detoxification procedures

Question 4

What are the 4 areas of physical dependence?

Answer 4

(definition)• Repeated use of drug alters physiological state such that continued admin is needed to prevent the appearance of withdrawal symptoms. A “reset” of homeostatic mechanisms
• Withdrawal
○ Genarally - rebound effects on the physiological systems that have been modified by chronic drug use
○ Usually opposite effects of the drug
○ Remember this can be fatal
• Cross dependence
○ Ability of a drug to suppress the withdrawal associated with physical dependence on another drug
○ Ie - use of benzos to suppress alcohol withdrawal
• Psychological dependence
○ Percieved need for drug. Craving.
○ In the ABSENCE of withdrawal physiology
• Addiction
○ Extreme example of compulsive drug use
○ Overwhelming concern with use of drug and securing its supply
○ Nebulous term, very culturally loaded

Question 5

What are the main drugs of abuse in the opiate/opioid category?

Answer 5

• Heroin
	• Morphine
	• Oxycodone (huge)
	• Methadone
	• Meperidine
	• Fentanyl
	• Hydrocodone (huge)
	• Codeine
	• (minor) loperamide - an anti-diarrheal
What action do opiates have in the CNS?
	• Interaction with endogenous opioid receptors (mu in particular)
	• Rush feelings likely histamine release

Question 6

What are the symptoms and treatment of acute opiate toxicity?

Answer 6

• Symptoms
○ Coma, respiratory depression/distress
○ Shallow breathing, cyanosis, apnea
○ Pinpoint pupils (myosis)
○ Low GCS
○ Areflexia, hypotension
○ TACHYCARDIA
○ Pulmonary edema
○ Cardiac arrhythmias (increased QT interval)
○ Convulsions (codeine, propoxyphene, meperidine)
○ Street drug contaminants can casue parkinsons - MPTP
• Treatment
○ ABCD of emergency, mostly manage the airway
○ Stabilize cardiopulmonary status
○ Naloxone admin IV helps increase respiration rate

Question 7

Discuss the tolerance, dependence, and withdrawal dynamics of opiates/opioids

Answer 7

• Tolerance develops rapidly and can be quite large, but that requires frequent use
• Mostly pharmacodynamic mechanisms
• Tolerance is unequal between organ systems
○ Little tolerance GI, lots of tolerance CNS and respiration
• Physical dependence also occurs rapidly
○ Withdrawal symptoms can be seen after 1-2 weeks of several doses/day
• Withdrawal symptoms are annoying BUT NOT MEDICALLY DANGEROUS
○ Early - restlessness, sleeplessness, yawning, nasal discharge, sweating
○ Late - agitation, chilling, anorexia, fever, muscle/joint pain, vomiting, diarrhea, abdominal cramps, muscle spasms, tachycardia, hypertension
○ CRAVING peaks at 36-72 hours
○ Protracted - anxiety, insomnia, craving (6 mo)

Question 8

How can you treat opiate withdrawal and/or prevent relapse?

Answer 8

• Clonidine
○ Alleviate symptoms of sympathetic nervous system overactivity
• Methadone/codeine
○ Substitution to alleviate symptoms via cross tolerance
• Buprenorphine
○ Partial agonist at mu opioid receptors with a low potential for overdose toxicity and long duration of action
○ Blocks acute reinforcing effects of heroin (blunts the rush)
○ Methadone + buprenorphine will blunt his and lows of heroin use and helps drug craving diminish
• Naltrexone
○ Opioid receptor antagonist
○ Blocks reinforcing actions of heroin

Question 9

What are the major (bolded in the notes) CNS depressants of abuse?

Answer 9

• Barbiturates
	• Benzodiazepines
	• Alcohol
		○ Also recognize the herbs
			§ Kava
			§ GHB
			§ GBL

Question 10

What psychological problem is commonly noted in people who are recovering from an overdose of a CNS depressant?

Answer 10

• Toxic psychosis is often seen during recovery from overdose
  
  • Patients often depressed and attempt suicide

Question 11

What are the symptoms of and treatment for CNS depressant toxicity?

Answer 11

• Symptoms
○ Confusion, talkativeness, emotional lability
○ Ataxia, depressed reflexes, miosis
○ SEVERE - respiratory depression, hypotension, possible coma and death
○ GHB is unique in causing seizures in acute toxicity
• Treatment
○ Supportive measures
§ Stabilize cardiopulm
§ Remove drug by inducing vomiting or gastric lavage
§ Monitor airway
○ Flumazenil for benzo toxicity
○ Alcohol - IV fluids of glucose, thiamine, multivitamins and electrolytes

Question 12

What do the depressant abuse drugs do in the CNS?

Answer 12

• Enhance the activity of GABA
• Barbiturates and alcohol will decrease the activity of glutamate at higher doses
• GHB has some effects on DA systems
• The effects leading to abuse
○ Euphoria, sedation, anxiolytic (escape emotional stress), body building (GHB)

Question 13

Describe the physical dependence and withdrawals aspects of CNS depressant abuse

Answer 13

• Major symptoms of withdrawal occur after only weeks of mild intoxication
• EEG and insomnia can be seen after as little as 1 week of ordinary usage at night
• Withdrawal is SERIOUS and can kill and should be treated as a lethal condition
○ All CNS depressants will produce withdrawal state after abrupt continuous admin of high doses
• Symptoms
○ Resemble rebound hyperexcitability
○ Insomnia, anxiety, sweating, anorexia, nausea, vomiting, muscular weakness, postural hypotension and tremors
○ SEVERE - grand mal seizures, fever, delirium, psychosis
• Treatment
○ Initiate reduction schedule or substitution therapy
§ Barbiturate or BDZ
○ Buspirone for anxiety
○ Monitor for seizures
§ Carbamazepine for seizure prevention
○ Attend to nutrition and electrolyte balance

Question 14

What are the major drugs of abuse in the CNS stimulant family?

Answer 14

• Methamphetamine, cocaine (bolded)
	• Amphetamine, methylphenidate
	• Weight reduction agents
		○ Phentermine, diethylproprion
	• Buproprion
	• Synthetic - cathinone, bath salts
	• MDMA or MDA have stimulant properties but are technically hallucinongens

Question 15

What do the stimulant drugs of abuse do in the CNS?

Answer 15

• Interaction with catecholamine NT systems
○ Especially dopamine for euphoriant properties
• Cause release or block reuptake of catecholamines
• Effects leading to abuse
○ Elevation of mood, feeling of exhilaration, sense of increased energy and alertness, decreased fatigue and need for sleep, decreased appetite

Question 16

What are the symptoms and treatment of acute CNS stimulant toxicity?

Answer 16

• Symptoms
○ Increase of sympathetic tone predominates
○ Rapid pulse, variable increases in BP, elevated body temp, sweating, increased motor activity
○ Vasoconstriction of fetal blood supply - pregnant women
○ OVERDOSE - super high BP, fever, chest pain that can progress to MI, fatal arrhythmias and strok-like CNS vascuclar spasms (can also cause hyperthermia and seizures)
• Treatment
○ General - cardiopulm support, gastric lavage, increase excretion by acidification of urine, control body temp above 102
○ Seizures - diazepam
○ BP elevation (diastolic above 120) - phentolamine
§ DO NOT USE beta blockers labetalol or propanolol because of unopposed alpha stimulation
○ Psychosis - DA receptor blocker haloperidol

Question 17

For CNS stimulants, is there physical dependence?

Answer 17

• Meh. Arguable
  
  • No major physiological symptoms that mean you should titrate down
  • HOWEVER, strong psychologic dependence

Question 18

What are the withdrawal symptoms and treatment for the CNS stimulants of abuse?

Answer 18

• Symptoms
○ Although patients who stop taking CNS stimulants will experience prolonged sleep, general fatigue, lassitude, hyperphagia and depression
§ Obvious physiological symptoms are generally absent
○ Early - intense craving and drug seeking
• Treatment
○ Behavioral
○ Monitor for suicide
○ TCAs and burpropion for depression and reduction of craving
§ Not all that effective
○ Topiramate
§ Reduces relapse rates
○ Modafinil
§ Used in narcolepsy that has been found to reduce cocaine-induced euphoria and relieve cocaine withdrawal symptoms
○ Interesting - cocaine vaccine?

Question 19

What does Nicotine do?

Answer 19

• Falls under the CNS stimulant class but it has it’s own receptor
  
  • Target - nicotinic neuronal receptor N-n
  • Effect leading to abuse - mild attention arousal and alerting effect

Question 20

What are the symptoms and treatment of acute nicotine toxicity?

Answer 20

• This happens most commonly after accidental ingestion of nicotine insecticide sprays or in children who ingest tobacco products (fatal dose = 60 mg)
• Symptoms (remember overall stimulation of all N-n receptors means overload of ANS which is organ specific for “who wins”)
○ Onset of symptoms is rapid in severe acute poisoning including nausea/vomiting, abdominal pain, salivation, diarrhea, headache/dizziness
○ Hypotension, difficulty breathing
○ Weak/irregular pulse
○ Terminal convulsions or death by respiratory failure
• Treatment
○ Gastric lavage or induction of vomiting followed by activated charcoal
○ Support for the cardiopulm problems

Question 21

What are the symptoms and treatment of nicotine withdrawal?

Answer 21

• Symptoms
○ Irritability, impatience, hostility
○ Anxiety, depressed mood, difficulty concentrating, restlessness, increased appetite/weight gain
○ Depression increases significantly during withdrawal and is cited as a major reason for relapse
• Treatment
○ Withdrawal and relapse prevention essentially
○ More of a public health issue at this point
§ Symptoms can be alleviated with nicotine replacement
§ Sustained release preparation of bupropion improves abstinence rates and in combo with nicotine replacement and behavioral treatment is the current treatment of choice
§ Other - varenicline, nicotine conjugate vaccine???
§ Rimonabant - cannabinoid receptor antagonist

Question 22

What are the two major classifications for hallucinogens that we were given?

Answer 22

• Ill defined class as it's kinda all the "other" addictive substances that don't fit into the other categories
		○ Indoleamines
			§ LSD - lysergic acid diethylamide
			§ DMT - NN dimethyl-tryptamine
			§ Psilocybin (mushrooms)
			§ Bufotenine (toad skin)
		○ Phenylethylamines
			§ Mescaline (peyote cactus)
			§ MDMA - ecstasy
			§ MDA
			§ MMDA
			§ DMA
			§ DOM/STP

Question 23

What do all the hallucinogens do in the CNS?

Answer 23

• Potency correlates closely with agonist action at 5HT-2 postsynaptic serotonin receptors
○ Thus this is thought to be the mechanism of action
• Effects of phenylethylamine (MDMA) also include dopamine release and effects a DA receptors
• Effects that lead to abuse -
○ Prominent alterations in perception
○ Altered or enhanced sensory perception, blurring of sensory modalities, mood elevation, dissociation from self and a feeling of unity with the environment
§ Good for concerts
○ (time course) Initial tension, then emotional lability, then hallucinations then detachment/sense of destiny
• Dose dependence for true hallucinations, so users just use the dose they want for desired effect

Question 24

What do you do with acute toxicity of LSD

Answer 24

• Symptoms
○ Psychological state dominates the clinical picture
• Treatment
○ Establish safety of the patient and others
○ Use nonpharm means for detox if possible
§ Talking down, isolation
○ Supplement with BDZ (diazepam, chlordiazepoxide) for sever agitation
○ Antipsychotic agents (haloperidol or risperidone) can be used if needed for control of behavior but generally not indicated as they can intensify the hallucinogenic experience

Question 25

Do hallucinogens have withdrawal or tolerance associated with them?

Answer 25

• No. they have no clinically significant withdrawal syndrome
  
  • However, most of this “no” comes from no evidence to say yes or no. Most people don’t abuse these unrelentingly in high doses

Question 26

What does THC stand for?

Answer 26

• Delta-9-tetrahydrocannabinol
  
  • The more common or traditoinal cannabinoid
  • Cannabinoids are available in 4 or more forms varying in their source and potency

Question 27

What are the different types of marijuana called and do they have different THC content?

Answer 27

• United States (just marijuana or THC)
		○ Tops of uncultivated plants
		○ 5-10% THC
		○ Though recent studies from Colorado say that retail cannabis averaged 18.7% THC with some more than 30%. Which is quite a bit
	• Ganja (place in eastern europe)
		○ Flowering tops/leaves of cultivated plants
		○ 5-10% THC
	• Charas (himalayan version)
		○ Resin at top of more mature plants
		○ 10% THC
	• Sinsemilla (spanish, without seed)
		○ Grown in thailand, hawaii, california
		○ 7-14% 
	• Bhang
		○ Concentrated hashish oil
		○ 10-30-60% (the more concentrated stuff)

Question 28

What are the symptoms of and treatment for acute THC toxicity?

Answer 28

• Symptoms
○ Phsyiological changes are minor with moderat intoxication and can include
§ Tremors
§ Decrease in muscle strength, balance, level of motor coordination
§ Increased reaction time, impaired ability to carry out multistep tasks
§ Thus the danger when driving
○ Can increase heart rate, precipitate seizures in epileptics, increase potential for ketoacidosis in diabetics
○ Psychologic conerns - mild levels of suspiciousness or paranoia with some loss of insight
○ Hallucinations and paranoid delusions can be seen at super high doses
○ Short term memory problems in acute toxicity
• Treatment
○ Nothing besides support and helping them into a calm environment

Question 29

Does marijuana use lead to chronic medical problems?

Answer 29

• No good evidence for brain damage either grossly or functionally
• The risk of any adverse consequences will increase with increasing amount, frequency of intake and length of exposure
• Some evidence - long term exposure leads to cognitive impairment
• More of a gradual, additive thing it looks like
• “amotivational syndrome” or impaired judgment, concentration and memory, apathy, loss of interest in conventional goals
• Pulmonary complications (from smoking)
○ COPD, laryngitis, pharyngitis

Question 30

Discuss what tolerance, physical dependence and withdrawal look like in marijuana use

Answer 30

• Tolerance - rapid build up but rapid loss too
• Dependence - high potential for it (10%) that leads to behaviors of preoccupation, compulsion, reinforcement, withdrawal after chronic use
• Withdrawal
○ Symptoms
§ Frequent users of high doses report symptoms like a mild withdrawal syndrome after stopping intake
§ Sleep disturbance, anorexia, irritability, dysphoria, lethargy, cravings, anxiety, nausea, malaise, headache
○ Treatment
§ None necessary usually but heavy users may suffer from accompanying depression and may need antidepressants

Question 31

What effects do the dissociative anesthetics have to make them addictive?

Answer 31

• Dose dependent effects
  
  • Low dose - floating feeling of euphoria and heightened emotionality
  • Intermediate dose - produce increased talkativeness, misperceptions of sensory input, feelings of unreality, changes in body image
  • Higher doses - associated with hostile or bizarre behavior

Question 32

What are the three main dissociative anesthetics that are used?

Answer 32

• PCP - phencyclidine
  
  • Ketamine (analog of PCP)
  • Dextromethorphan - extremely high doses of a cough syrup
  • These all act as an antagonist at NMDA-type glutamate receptors
  • Blocks reuptake of dopamine and serotonin and increases dopamine release in limbic and cortical structures

Question 33

What symptoms make you suspect acute PCP or ketamine toxicity? What do you do about it?

Answer 33

• Toxic profile of PCP is legendary and PCP patients are most difficult of all overdose victims to manage
○ Narrow range between dose that produces mild intoxication and dose that causes toxic reaction
• Symptoms
○ Begin with delirium, increased respirations, hypertension, tachycardia, hyperpyrexia, muscle rigidity
○ increased DTRs, sterotypies, blank stare
○ Later - suporous then comatose, seizures common
○ Patients can die from respiratory or cardiac complications
○ Behavioral syndrome at higher doses
§ Belligerence, impaired judgment, agitation and violent, combative behavior
§ Psychosis (can last a while) and personality changes are possible
○ Patients more often die from trauma under their intoxicated state than any other manner
• Treatment
○ No specific antagonist available
○ Support vitals, control hyperthermia, treat hypertension and convulsions
§ Convulions - Phentolamine, hydralazine, diazepam
○ Caution with treating psychosis with haloperidol (antipsychotic). They can increase seizure risk
○ Behavioral control, though difficult, can be with benzos to calm without seizure risk
○ If psychosis is prolonged, screw the seizure risk and treat with antipsychotics

Question 34

What are the “drugs” that people are looking for when they “huff” normal everyday materials/cleaners?

Answer 34

• Glues and adhesives
		○ Toluene
		○ Hexane
		○ Benzene
		○ Methyl chloride
		○ Acetone
		○ Xylene
		○ Chloroform
		○ Trichloroethyele (PVC cement)
	• Aerosol propellants
		○ Fluorinated hydrocarbons plus butane, toluene, propane
	• Cleaning solutions
		○ Tetra and trichlorethylene, trichloroethane, carbon tetrachloride, petroleum products
	• Paints, paint thinners, correction fluids, nail polish removers
		○ Toluene, methanol, acetone, ethyl acetate, methylen chloride
	• Fuels
		○ Gasoline, butane, isopropane

Question 35

What do the “drugs” in paint thinners or glues do in the CNS that lead to abuse?

Answer 35

• General CNS depression
  
  • Possibly achieved by altering membrane permeability in lipid rich neuronal membranes, altering neurotransmission
  • Causes euphoria, feelings of giddiness, dizziness, lightheadedness
  • Often accompanied by decreas in inhibitions, floating sensation, misperceptions, clouding of thoughts
  • “high” begins quickly, within minutes, lasting about an hour

Question 36

What is the symptomatic evidence that someone has been huffing glue/paint thinners? What do you do about it?

Answer 36

• (acute toxicity)
• Symptoms
○ Similar to alcohol intoxication
○ Range from excitation and euphoria, through dizziness, slurred speech and motor impairments to acute psychosis with delusions and hallucinations, followed by CNS depression
○ Nausea, vomiting, diarrhea possible as well as respiratory irritation and shallow respirations/wheezing
○ Symptoms are transient and minimal, but many deaths occur as a result of plastic back suffocation
§ People use the bag to increase the conentration of the vapors)
○ And “sudden sniffing death syndrome” probably due to cardiac arrhythmias
• Treatments
○ Nothing special. Supportive care
○ Watch for arrhythmias and need for pulmonary stabilization

Question 37

What anticholinergic agents could be used as a drug of abuse, and why would they be used that way?

Answer 37

• Anticholinergics can lead to mood elevation, hallucinations and delirium
  
  • Ach is used in the brain and on the Nac!
  • Trihexyphenidyl, biperiden, benztropine, scopolamine, atropine

Question 38

What is the evidence for acute toxicity in anticholinergic agents?

Answer 38

• Disorientation and delirium
• Dry skin and mouth
• Flushed face
• Fever
• Unreactive pupils, blurred vision
• Profound memory impairment often present
○ Treatment - very careful use of physostigmine if necessary
○ Benzos for extreme behavioral excitation

Question 39

Which drugs of abuse have the ++ in the toxicity or overdose column?

Answer 39

• Depressants
• Stimulants
• Inhalants
○ One plus = hallucinogens, PCP, OTC drugs

Question 40

Which drugs of abuse can cause depression or anxiety?

Answer 40

• Depressants (major)
  
  • Stimulants (major)
  • Opioids
  • Hallucinogens
  • OTC

Question 41

Which drugs of abuse can cause psychosis?

Answer 41

• Depressants (less so)

* Stimulants and cannbinols (at high concentrations)

Question 42

Which drugs of abuse can cause delirium or dementia?

Answer 42

• Depressants
  
  • Inhalants
  • PCP
  • OTC drugs

Question 43

Which drugs of abuse have the ++ in the withdrawal column?

Answer 43

• Depressants and opioids

* The other one to note is stimulants have withdrawal, but less

Question 44

In terms of the Nac and DA, what is the end result of every drug of abuse?

Answer 44

All substances of abuse increase dopamine release in the shell of the nucleus accumbens

Question 45

What’s the technical difference between mild, moderate and severe substance use disorders?

Answer 45

Mild: presence of 2-3 symptoms.
Moderate: Presence of 4-5 symptoms.
Severe: Presence of 6 or more symptoms.

Question 46

When is substance use considered an actual disorder?

Answer 46

Mild: presence of 2-3 symptoms.
Moderate: Presence of 4-5 symptoms.
Severe: Presence of 6 or more symptoms.
• SUD = substance use disorder
• When:
○ Taken in larger amounts or longer than it’s intended
○ Persistent desire or unsuccessful efforts to cut down or control use
○ Lots of time spent in activities necessary to obtain or use
○ Craving or strong urge to use
○ Use causes failure to fulfill major role obligations at work school or home
○ Use even though there’s social pressure to quit
○ Social, occupational or recreational activities sacrificed for use
○ Physically dangerous situations to use
○ Use despite knowledge of a problem
○ Presence of tolerance to drug
○ Withdrawal upon quitting

Question 47

What are some comorbidities of alcohol abuse?

Answer 47

Hepatitis, pancreatitis, Wernicke-Korsakoff syndrome (confusion, ophthalmoplegia, ataxia - necrosis of mammillary bodies - caused by thiamine deficiency)

Question 48

What are some comorbidities of heroin abuse?

Answer 48

Respiratory suppression, right-sided endocarditis, abscesses, hepatitis, HIV

Question 49

what are some comorbiditeis of tobacco abuse?

Answer 49

COPD; heart disease; cancer of lung, head and neck, stomach, kidney, bladder, cervix, uterus; osteoporosis; infertility; placenta previa; placenta abruptia; low birth weight

Question 50

What are the two most common withdrawal syndromes you will have to treat? How do you treat them?

Answer 50

Withdrawal from alcohol:
Think of symptoms as causing the opposite of the drug effect. Alcohol=CNS depressant. Withdrawal=tachycardia, diaphoresis, tremulousness, etc.
Potentially life threatening (delirium tremens)
Generally treated with a benzodiazepine taper.
Withdrawal from opioids:
Symptoms opposite of drug effect: aching or deep bone pain, diarrhea, pupillary dilation,
piloerection (the term “going cold turkey” is derived from this)
Not life threatening
Medication approaches include: supportive medication (e.g., medication to stop diarrhea), clonidine, and methadone/buprenorphine.

Question 51

NRT, Bupropion, and Varenicline are all common drugs used in what substance use disorder to treat withdrawal and discourage relapse

Answer 51

Tobacco abuse

Question 52

What are the principles of psychosocial substance use disorder treatment?

Answer 52

OARS ERDS
	O pen ended questions
	A ffirmations
	R eflective listening
	S ummarizing

	Express empathy
	Roll with resistance
	Develop discrepancies
Support self-efficacy

Question 53

As a physician that knows the chemistry of addiction, you understand that it’s a long road to recovery. Thus you need to have contingency plans. What are these?

Answer 53

Utilize a behavior that can be reliably detected (e.g., refraining from drug use and determined by urine drug screens).
Develop a behavioral plan, where reinforcers are provided with the behavior.
Develop a behavioral plan, where reinforcers are withheld when the behavior does not occur.
Identify and utilize reinforcers, which are motivating for this patient.
Positives reinforcers may change behavior more than punishment.
The more quickly that reinforcers can be paired with the behavior, the more likely behavior is to
change.
Fish bowl method can reduce costs.

Question 54

CBT in substance use/abuse looks like what?

Answer 54

This approach utilizes relapse prevention planning to carefully identify and then plan ways to avoid triggers for relapse.
*When triggers cannot be avoided, strategies (plan for what to do) and also approaches to reframing cognitions (e.g., while craving may be viewed as unrelenting unless the individual uses, this is a distorted thought – instead craving is more like a wave and will rise, crest and then fall – this reframe sometimes is termed “urge surfing”) are employed.