Understanding Substance Use Disorders: Types, Effects, and Risks

the topic of this lecture is substance use and abuse so substance use disorders are

compulsive refer to a compulsive pattern of drug use despite negative consequences at least that's how they're

defined in the DSM-5 the DSM is the diagnostic and statistical Manual of mental disorders that are used to

diagnose and understand mental disorders of various types with substance use disorder being being one of those

these types of disorders involve physical as well as psychological dependence which we'll talk about in

just a few moments so psychoactive drugs are going to be chemical substances that modify our

mental emotional or behavioral functioning some examples include things like cocaine and marijuana but also

things like caffeine would also classify as a psychoactive drug there are a number of reasons why people

take psychoactive drugs in some cases they produce a pleasurable Sensations that people enjoy experiencing in other

cases people take them in order to engage in what's referred to as self-medicating so they may take these

drugs because they think the experience is going to to deal with some issue that they're having for example if someone's

experiencing a lot of anxiety Then they may use something like marijuana in an attempt to try to to moderate their

their feelings of anxiety now whether or not it's successful is a different issue but they'll if they're frequently

various reasons for engaging in various types of psychoactive drug use recreational and pleasurable uses are

certainly a prominent but not the only reason for doing this continued use of these sorts of

psychoactive drugs have a number of consequences for example tolerance is going to be one

consequence tolerance refers to situations where larger and larger doses are necessary to get the same basic

effect for example if people are frequently using alcohol what will happen is they'll over time they'll

develop a tolerance so for example the first time you drink alcohol may be drinking half a beer is enough to get

you kind of buzzed and feel a little intoxicated if you've been drinking alcohol regularly over a period of time

you may need to have three or even four beers to get the same effect that you used to be able to get off of like half

of a beer that's the idea of Tolerance is that larger doses of whatever substance it is are necessary in order

for you to feel the effects of the drug physical dependence is another consequence of prolonged use

physical dependence is when the body is unable to function normally without the drug so when people are physically

dependent right their body has basically habituated to the frequent presence of whatever the substances the person is

using psychological dependence is related to physical dependence but it's different

psychological dependence refers to feeling that a drug is necessary in order to experience emotional well-being

or daily functioning right so psychological dependence is when you believe that you need the drug in order

to kind of function normally physical dependence is when your body actually needs the drug in order to function

normally withdrawal is going to refer to physical symptoms that occur due to the lack of a

drug and this is going to be as a consequence of physical dependence so for example common symptoms of

withdrawal involve things like nausea pain Tremors high blood pressure all of those are physical symptoms of

withdrawal the severity and type of withdrawal symptoms will depend on the drug that's

being used as well as the extent to which people have been using the drug over time so for example if people have

been using alcohol quite regularly their withdrawal symptoms may be actually fairly significant and severe if they if

they stop using alcohol cold turkey in other cases and withdrawal symptoms aren't unique to things like alcohol or

cocaine for example you can also experience withdrawal symptoms from more everyday sorts of drugs like caffeine uh

for example I used to drink a lot of coffee as well as a lot of soft drinks and then I I tried cutting down my

caffeine intake because soft drinks aren't terribly great for your health under any circumstance but I was also

having sleep problems as I've mentioned previously and so what happened is as I started cutting down on my caffeine I

experienced a lot of withdrawal symptoms like caffeine headaches from from not having enough caffeine right and

caffeine in all by all for all intents and purposes caffeine is a fairly minor drug compared to some of the ones we've

been talking about but even that can create physical dependence and withdrawal symptoms if you're deprived

of something that you're used to having there are different ways of categorizing psychoactive drugs so this is just one

way of kind of categorizing them we can have something like antipsychotic drugs like Haldol and Risperdal stimulants

depressants and hallucinogens they're also opioids which we'll be talking about common stimulants involve things

like cocaine amphetamines caffeine common uh depressants or things like alcohol and barbiturates we have

hallucinogens like LSD and mescaline marijuana is kind of a tricky drug that we'll talk about because it really kind

of Falls at the intersection of hallucinogens depressants and stimulants it's most often categorized as a

hallucinogen but it also has some depressant as well as paradoxically some stimulant properties that we'll we'll

talk about as we go on so let's spend a few minutes talking about common classes of drugs and some

of their basic effects so let's start with stimulants some common examples of stimulants are things like cocaine

amphetamines medications such as adderall methamphetamines any of those would

classify be classified as stimulants the basic effects on the body even though they vary a bit is one of the things

they're all going to share is they're going to increase heart rate blood pressure and body temperature overall

some of the effects that people will experience when using these sorts of drugs things like increased alertness

mild feelings of euphoria a decreased appetite and at least low doses if people expect people take higher doses

of these drugs you may see some agitation paranoia hallucinations in some cases we talked a bit about the

idea of like cocaine-induced psychosis which we talked about previously and this has to do with

because cocaine is impacting dopamine levels so you can see some of these paranoia sorts of ideas and

hallucinations stimulants can absolutely be addictive people can get addicted to cocaine

amphetamines these other sorts of meds as well other sports drugs or medications

the second class of drug will be the sedative for hypnotics also known as depressants uh common depressants are

things like alcohol barbiturates benzodiazepines um what these drugs do is they tend to

decrease our heart rate and blood pressure in the low doses these sorts of drugs increase relaxation they decrease

our feelings of inhibition part of the reason why people consume alcohol is because it decreases inhibitions it's

often referred to as kind of the social lubricant because people drink in situations where they might be

uncomfortable and drinking reduces inhibitions and allows them to do things like socialize more freely

high doses of these drugs can induce sleep they can cause motor disturbances memory loss they can also interfere with

respiratory function and in high enough doses they can lead to death especially in combination

these sorts of depressants can absolutely be physically addictive and psychologically addictive as well

for example when we're talking about these depressants it's commonly recommended that people not mix things

like barbiturates or benzodiazepines with alcohol so if you're taking those sorts of medications you want to avoid

drinking alcohol because of their multiplicative effects the third class of drug will be opiates

these involve things like opium heroin fentanyl morphine oxycodone and so on the effects of the these drugs on the

bodies are going to decrease pain they're going to increase people dilation they're going to decrease our

gut motility they're going to in they're going to decrease respiratory function the way that we experience these sorts

of drugs is they lead to pain relief Euphoria feelings of sleepiness in high doses these can actually cause death due

to respiratory depression basically they stop our respiratory system from working correctly

opiates can be both psychologically and physically addictive the last class of drugs we want to talk

about are hallucinogens these involve things like marijuana LSD peyote mescaline and so on

some of the effects on the body they tend to increase heart rate and blood pressure but this dissipates over time

the psychological experience is it tends to lead to some mild and sometimes intense perceptual changes there's a lot

of variability in the extents which people experience these sorts of changes depending on the sort of strain that's

being used or the dose or type of the the drug that's being ingested as well as individual differences like previous

experience with the drug and expectations as well and there's some psychological addictive

properties of these uh drugs as well so let's go into a little more detail about stimulants

one of the things that stimulants do is they worked it by increasing overall levels of neural activity

usually these dopamine agonists they usually they function as dopamine agonists which work by preventing the

reuptake of dopamine for example we talked about that in the context of cocaine previously

dopamine activities associated with reward and craving so these drugs can definitely be highly addictive some

common stimulants things like cocaine amphetamine things like bath salts MDMA any of those would class be classified

as stimulants under most categorization strategies some of the side effects of stimulants

include things like nausea elevated blood pressure increased heart rate feelings of anxiety hallucinations and

paranoia can also happen if the doses of the drug are high enough caffeine and nicotine are also

stimulants that having more on an everyday kind of level so caffeine involves uh adenosine

activity and it's going to increase levels of alertness and arousal so for example if you drink a lot of coffee if

you drink uh highly caffeinated beverages like Red Bull or those sorts of things you're getting large amounts

of caffeine for example sodas and those sorts of things also even though the level of caffeine isn't ridiculously

high in each one if you're drinking a lot of soda or or if you're drinking large sodas like 40 ounce sodas you can

you can be ingesting more caffeine in some cases Than People realize they're ingesting

nicotine which is common in cigarettes it's going to interact with a set of cute acetylcholine receptors nicotine is

a highly addictive drug part of the reason why cigarettes are so addictive is because the nicotine levels and this

is going to play a role in arousal and reward mechanisms as well so nicotine is extremely addictive and if if you if

you're if you're a smoker my suggestion is you want to try to stop smoking as soon as possible there's so many

negative harmful Health impacts of smoking caffeine also isn't a great drug either so Trying to minimize your

caffeine is also a really good idea depressants or drugs that suppress central nervous system activity usually

these are Gaba agonists which have a quieting effect on the brain basically what they do is they kind of they bind

to Gaba receptors which makes the neuron less likely to fire um these include things like alcohol

barbiturates anti-convulsant medications are common they are benzodiazepines anti-anxiety medications also also show

up here alcohol has a number of consequences it reduces our reaction time or increase it

basically makes our Reaction Time slower it reduces our visual Acuity it also makes us less alert less aware of what's

going on around us it can reduce our behavioral control in some cases it reduces our inhibition we may do things

when we're intoxicated that we wouldn't do if we were perfectly sober in some cases large enough levels of alcohol

ingestion can lead to complete loss of consciousness opioids are another class of drug these

serve as analgesics basically they decrease pain sensation through their effects on the endogenous opioid

neurotransmitter system basically they function as if they were opioids they function as if they're going to be the

sort of neurotransmitters that are going to be reducing our sensation of pain these are really really addictive uh

some of the most common uh of the opioids or things like heroin morphine methadone and codeine

the last class of drugs we want to talk about are hallucinogens these cause changes in our sensory and perceptual

experiences we were just talking about previously these can involve in some cases really Vivid hallucinations that

can be pleasurable for some individuals or can be really disconcerting for others right depends on a number of

factors about how people will experience these sorts of hallucinogenic States there's a lot of variability with regard

to the specific neurotransmitter systems that they affect mescaline mescaline and LSD for example affects serotonin PCP

and ketamine affect the nmda glutamate receptor antagonists and so there are different drugs that are working on

different neurotransmitter systems