Welcome to Last Minute Lecture.
This free chapter overview is designed to help students review and understand key concepts.
These summaries supplement not replaced the original textbook and may not be redistributed or resold.
For complete coverage, always consult the official text.
Welcome to the Deep Dive.
We take complex topics and, well, we try to boil them down to the essentials you really need.
Today, we're jumping into a really significant area of health, substance use disorders.
I mean, the scale is just enormous when you look at it globally.
We hear about the opioid crisis constantly, but then you see tobacco use as the fourth leading cause of death worldwide.
Alcohol use right behind it, number five.
It's huge.
It really is a critical subject.
And for this deep dive, we're grounding ourselves in some core psychiatric principles, drawing directly from a key chapter on substance use disorders in Kaplan and Saddock's comprehensive textbook of psychiatry.
Okay, so our mission here is to pull out those foundational concepts, how diagnoses have changed, the theories behind why these disorders develop, and crucially, what treatments actually work, according to the evidence.
And maybe the most important frame for you listening, we're talking about SED, substance use disorders, not as some kind of moral issue, but as chronic biopsychosocial diseases.
Think of them like hypertension or diabetes.
Exactly.
And maybe one central idea to keep in mind right from the start is this concept of
a dysregulation of choice.
That seems to be the thread connecting all these conditions, whether it's drugs or even something like gambling disorder.
It's this impaired ability to control behavior around the substance or the activity.
Okay, dysregulation of choice.
Let's start unpacking that.
How does the medical field actually diagnose this?
The DSM -5 -TR, the big diagnostic manual, made some pretty major changes, right?
Oh, absolutely.
The single biggest change was unification.
They basically took what used to be two separate things, substance abuse and substance dependence, and emerged them into one single spectrum.
It's now just called substance use disorder, SUD.
It simplifies things, I guess.
It does simplify the naming, yeah.
But the core features people think about with addiction, they're often still captured by what some call the three Cs, losing control over use, intense craving, and continuing despite negative consequences.
So they unified the main diagnosis.
Did they change the checklist, the actual criteria someone needs to meet?
They did refine it.
It's now a list of 11 criteria.
And the big change there was adding, craving that really strong urge or desire to use as its own specific criterion.
Interesting.
What else?
They also took out the criterion about legal problems.
The thinking was that legal issues are just too variable, you know, depending on laws and enforcement in different places.
It wasn't a reliable clinical indicator worldwide.
Okay, so if it's one diagnosis now, how do clinicians show how serious it is?
Is it just yes or no, you have an SUD?
No, and this is really key.
It's shifted from being purely categorical yes, no, to being dimensional.
It's about severity.
Ah, like a scale.
Exactly.
How many of those 11 criteria you meet determines the severity?
Two or three criteria means it's mild.
Four or five, it's moderate.
And if you meet six or more criteria, that's classified as severe.
That makes a lot more sense clinically.
It allows for nuance.
Precisely.
It gives clinicians and researchers much more precision, especially when thinking about, say, who needs more intensive treatment like inpatient care.
Okay, understanding what the diagnosis naturally leads us to the why.
Why do some people develop these severe SUDs, this dysregulation of choice, while others don't seem to?
Let's get into the etiology.
Biology plays a huge role, doesn't it?
Oh, massive.
The sources really stress the genetic contribution.
For alcohol use disorders, AUDs, they estimate that genetic factors account for something like 50 % to 60 % of the risk.
That's substantial.
Wow, over half the risk.
Is it like one specific gene?
No, not usually.
It's more like a whole network of genetic influences interacting with environmental factors.
It's complex.
So if genetics contributes that much risk, what are the actual biological ways that risk shows up?
How does the biology translate into behavior?
Well, the text highlights two really well -studied biological mediators.
One is related to the enzymes that metabolize alcohol in the body.
Differences there can affect how intensely someone feels alcohol's effects or how quickly they clear it.
Okay, that makes sense.
What's the other one?
The other is something called a low level of response to alcohol, sometimes abbreviated as low LR.
Basically, these individuals need to drink significantly more alcohol to feel the same effects, the relaxation, the sedation that others feel at lower doses.
Ah, so if you need, say, twice as much alcohol just to feel anything, you're naturally going to drink more each time.
Exactly.
You're inherently consuming larger quantities per occasion, which directly increases your risk over time for developing an AUD.
It's like the natural break isn't working as effectively.
That biological pull is strong, but it's not just biology, right?
Psychology and social factors must play a huge part too.
Absolutely critical.
Things like expectations matter a lot.
The sources point out that if you expect drinking to be really fun or to relieve anxiety, you're more likely to drink heavily.
And the social side.
That's where it gets kind of insidious.
People tend to consistently overestimate how much their friends or peers are actually drinking, so they compare their own maybe heavy drinking to this inflated idea of the norm, and it makes their own patterns seem more acceptable or average than it really is.
It's like a feedback loop.
Biological vulnerability meets social normalization.
And it's interesting, the book points out this motivation isn't the same for all substances,
using hallucinogens as an example.
Yeah, that's a really good point they make.
Classic hallucinogens like LSD or psilocybin, generally speaking, they aren't reliably reinforcing in animal studies.
They don't light up the brain's reward circuits in quite the same way as, say, cocaine or alcohol.
Meaning the reason people use them is different.
It suggests the motivation is often different, yeah.
It might be more about seeking a particular kind of experience, the setting, the mindset.
It's not necessarily that compulsive, reward -driven pattern we see with many other addictive substances.
It really reinforces that idea of dysregulation of choice being the key, not just one specific brain pathway for all drugs.
That difference leads us right into a major clinical headache.
You've got a patient, they seem depressed or anxious, maybe even psychotic, but they also use substances heavily.
How on earth does a clinician figure out which came first, the chicken or the egg problem?
It's one of the most critical distinctions to make in clinical practice.
Separating an independent psychiatric disorder from a substance -induced disorder.
Is the depression causing the drinking or is the drinking causing the depression?
So how do you untangle that?
Is there a rule of thumb?
There is a specific method,
the timeline approach.
You have to look carefully at the history.
Did the psychiatric symptoms clearly start before the heavy substance use began?
That points towards an independent disorder.
Okay, what if the timeline isn't clear?
Then the other critical piece is persistence after stopping the substance.
The symptoms have to persist for a significant period, typically defined as a month or more, after the person achieves abstinence.
Ah, so if the depression lifts within, say, two weeks of getting sober.
Then it strongly suggests it was a substance -induced disorder.
The text gives a great case example.
A woman was convinced she had always been depressed, but after just three weeks off alcohol, her mood symptoms completely resolved.
Her final diagnosis,
alcohol -induced mood disorder.
That one -month abstinence window is the key diagnostic test then.
Okay, let's shift gears slightly and get into some specifics about different substances, make this really concrete.
Let's start with alcohol.
Sure.
First, the basics.
Yeah.
A standard drink that's generally defined as containing about 10 to 12 grams of pure ethanol.
Think 12 ounces of regular beer, five ounces of wine, or a 1 .5 ounce shot of 80 proof spirits.
How does that affect blood alcohol levels?
Typically, one standard drink will raise your blood alcohol concentration, or BAC, by about 15 to 20 milligrams per deciliter.
Your body metabolizes it at roughly that same rate, about 15, 20 milligdL per hour.
What's a major warning sign clinicians look for with alcohol?
A really serious one is the blackout.
We're talking about anterograde amnesia here, not remembering events that happened while intoxicated, even though you were conscious.
This can happen at BACs, often between 200 and 300 milligdL, and it's a clear red flag that an alcohol use disorder is likely present or developing.
Okay, moving on to opioids.
The text emphasizes the interaction with one specific receptor, right?
Yes, the opioid receptor, new opioid.
How different drugs interact with this receptor basically defines both the problem substances and the treatments.
Can you break down those interactions?
Sure.
You have full agonists.
These bind to the receptor and activate it fully.
Think heroin, fentanyl, oxycodone, and also methadone, which is used in treatment.
Then you have partial agonists like muprenorphine.
It binds strongly, but only activates the receptor partially, creating a ceiling effect.
It's safer and can block full agonists.
And the third type.
Antagonists.
These bind to the receptor, but don't activate it at all.
They block it.
Naloxone, used for overdose reversal, and naltrexone, used for preventing relapse, are the key examples here.
Got it.
Now, stimulants like cocaine and methamphetamine, the book highlights something different there related to how they're used.
Absolutely.
With stimulants, the route of administration is incredibly important.
Faster delivery to the brain means a faster, more intense euphoria, which is strongly linked to developing compulsive use.
So smoking or injecting is riskier than snorting?
Exponentially riskier, yes.
Smoking crack cocaine or injecting meth gets the drug to the brain almost instantly, making it much more reinforcing and addictive.
And this rapid high dose use is also tied to a really high rate of psychiatric side effects, particularly psychosis.
About paranoia.
Exactly.
The text cites figures like stimulant -induced paranoia occurring in 50 to 70 percent of regular cocaine users and nearly 30 percent of methamphetamine users.
It's very common.
We know.
Yes.
There's a dose connection mentioned.
Yes, that's a key point.
While medically supervised, low doses might be used therapeutically, the chapter focuses on the high superphysiologic doses, often seen in non -medical use, sometimes exceeding the equivalent of a thousand milligrams of testosterone per week.
And those high doses cause problems.
They're strongly linked to severe mood issues, significant irritability, aggression, episodes that look like hypomania, and sometimes even full -blown mania.
It's often these psychiatric effects at high doses that bring users to clinical attention.
Okay.
That covers a lot of ground on the what and why.
Let's turn to solutions.
What does the evidence say about effective treatments?
Treatment really spans psychosocial approaches, medications, and support systems.
On the psychosocial side, several are cornerstones.
Like therapy?
Yeah.
Things like cognitive behavioral therapy, CBT, focusing on changing thought patterns and behaviors.
Motivational interviewing, MI, is also key, helping people find their own reasons and motivation to change rather than just telling them to stop.
And 12 -step facilitation, TSF, which helps connect people to mutual support groups like AA or NA.
You mentioned stimulants earlier.
Yes.
Is there one therapy that stands out for those?
Yes, definitively.
Contingency management, CM, consistently shows the best results for stimulant use disorders.
How does that work?
It's actually pretty straightforward behaviorism.
It directly competes with the drug's powerful reward by providing tangible rewards like vouchers or small prizes for objective proof of positive behaviors, usually negative urine tests or attending treatment sessions.
It gives an alternative reinforcement.
Makes sense.
What about medications,
especially for opioids and alcohol?
Medications are absolutely vital, particularly for opioid use disorder.
We call it MOUD medication for opioid use disorder, and it uses those three types of drugs we discussed.
The agonist, partial agonist, and antagonist.
Exactly.
Methadone, the full agonist for maintenance therapy, buprenorphine, the partial agonist, often combined with naloxone, and naltrexone, the antagonist, usually as a long acting injection.
These are the FDA approved standards of care.
And for alcohol use disorder?
For alcohol, we also use naltrexone, primarily to reduce craving and the rewarding effects of drinking if someone does slip.
And another important one is acamprosate.
What does acamprosate do?
It seems to work on glutamate signaling in the brain, helping to calm down the protracted withdrawal symptoms that lingering anxiety, insomnia, restlessness that can persist long after detox and often trigger relapse.
Is disulfiram still used, the one that makes you sick if you careful patient selection and often directly observed therapy because drinking on it can cause a severe, potentially dangerous reaction?
It's less commonly used now compared to naltrexone and acamprosate.
And beyond therapy and meds, the role of peer support is really emphasized now, too.
You mean like support groups?
That's part of it, but also the growing movement of trained peer recovery coaches.
These are individuals with their own lived experience of addiction and who are trained to mentor and support others.
What's key about their approach?
A really important aspect highlighted is that they support multiple pathways to recovery.
They recognize that recovery doesn't look the same for everyone.
It might involve 12 -step, it might involve medication, it might involve therapy or moderation management.
For some, it's about finding what works for the individual, not pushing one single solution.
That seems like a really holistic view.
So wrapping up this deep dive,
we've covered the shift to a dimensional diagnosis for SUDs, the huge role of genetics and neurobiology interacting with psychological factors, this core idea of dysregulated choice.
And the evidence showing that combining psychosocial therapies like CBT or CM with medications like MOU or naltrexone and acamprosate for alcohol gives the best outcomes, plus the growing importance of peer support.
Okay, for a final thought, something to leave pondering.
The text throws out a striking statistic.
94 % nearly all adult inhalant users also meet criteria for another substance use disorder, usually alcohol or other drugs.
So given that incredibly high comorbidity and knowing that many different substances, alcohol, opioids, even AASA seem to tap into shared neurobiological pathways, particularly involving dopamine and the brain's own opioid system, here's the question.
How might understanding biological overlaps influence how a clinician approaches treatment when someone is struggling with multiple substances at the same time?
Where do you start?
What do you prioritize?
Does treating one help the other?
That challenge effectively treating polysubstance use based on shared mechanisms is really where the cutting edge of addiction treatment is today.
Thank you for joining us for this deep dive into substance use disorders.
We hope it gave you some valuable insights.
We'll catch you next time.