hello everybody my name is pat lawrence and welcome to mental health matters and it certainly does today we're going to be talking about something that has confused parents for while i'd say ever since the beginning of time and that the teen brain and good percentage of you have teenagers or a head teenagers and  have scratched your head saying you know what are they doing this and what's wrong with them had cetera et cetera so but today is my guest i have dr morris's still very who works at did you ever want to be a ph d in doctor and delve into all of this it's a good question i've always been interested in science isn't even predating my own teenage period i was always interested in relationships between things and how the brain worked and then my interest in science so i'm formally trained as a behavioral neuroscientist and i went to union college as an undergraduate and there i was exposed to this course that at the time predated what is today's neuroscience it was called biological psychology or psychobiology and essentially it was the study of biology of the brain and it was incredibly fascinating because it was a way to look and understand and appreciate all of the cellular things that go on in the brain to make up what we know to be ourselves so our mood our motivation our drive our happiness or lady had died of there and i don't remember what it was and it was yellow and i imagine it was it was some sort of plaque or something and but it was just so interesting and in my next life i'm going to come back if you so anyways want to go on to what you were doing you were into research and you're into research with are all that great stuff are you into with pet scans and things like that well so the type of imaging we do in so to bring it back to that opportunity to hold a human brain in your hands which is amazing i mean i have three pounds of matter right right that really matter that really matter what's really interesting is that we know so many things about the brain most of which we've learned you know throughout time in many ways by studying people who had a problem so they had a brain injury or they've had a tumor we studied the brains after they passed away or we've studied animal models to get at how the brain functions in so part of the reason why we employ imaging technology we actually use magnetic resonance technology which is a little different than a pet s i is actually a noninvasive technology and that is the most advantageous to use in particularly pediatric populations because we certainly you know there are benefits in costs to any type of imaging particularly with pet scans because there's exposure to something that's radiation with m r i there's no exposure to anything harmful and the best aspect of an m r i is that it's repeatable in so if you want to study the developing brain the best me means to do that is to be able to look at brain changes now from zero to ten i mean you've got this tiny baby and you keep on going in ten years old the brain is partially developed and from ten on i know it gets bigger but as far as learning and things like that i mean does that  do anything with the brain can you tell how it is developing through college grads through can you i know there's so much they don't know about the brain what do they know about the brain well you raise an important point so you see in the first decade of life that you have these infants who are really dependent on their caregiver they can't do anything they can't feed themselves they can't put themselves to sleep they can't walk yet in so slowly over those first ten years you start to see them develop all these amazing skills and it's essentially sensory integration with the world so being able to walk into know their collars and to be able to start to speak and to use language and to read and you would think that with that first ten years you know there are dramatic changes in the brain and that is true and one of the things that's actually known is that by the time you reach around age five or six your brain actually gets no bigger for the rest of your life so it reaches a plateau in size but what change is you know we like to think about this in terms of a major construction project so by the time you reach age five or six your brain gets no bigger however we know that in the second decade of life what we collectively think of as adolescence are the teenage period we know that those kids in that time frame get exceptionally more able to perform tasks well to organize to plan to do all the things you know the higher cognitive abilities and so the biology that underlies that is really internal changes so it's not getting bigger but it's redefining itself in so you can actually see that in them or i scan in the ways you see that can give you the two second brain the two major processes that happen are that you know that the trillions of cells that our brains are made up of you know we're born with more neurons then we'll have in our lifetime in slowly through the process of development we prune away the inefficient ones right so one thing about the brain is it's incredibly redundant and so there are a lot of connections and possible connections to other parts of the brain so that we can get it right in so that at some point one of the goals of particularly teenage brain development is to improve how well those neurons talk to each other and so you know we think about this when i talk to audiences of teenagers so there have been times when i've had an audience of a thousand teenagers listening to me talk about how their brains are developing so we tell them that you know those are the things that happen one of the other processes that occurs is called myelination is that myla nation is when you take two neurons and you make you improve the connections between them so there's the actual neuron itself and it's made up of the cell body and then it has these long projections called axons and it's those axioms that will be the connection to the neighboring neuron now they're not physical connections they come up really close and then they transmit neurotransmitters and have all sorts of connections or communications to neighboring cells in so my my neuro scientist joke is this is how you get better cell service i was a teenager so we could think about it that way do you want to have the brain that has one bar or do you want to have the brain that has five bars and so the way this happens is that we have increases in mile a nation or white matter in the brain so that's all the conic to the right the connections between parts of the brain and then we also at the same time if we're conserving the matter right because our brains aren't getting any bigger but if we're adding all this myelination and insulation between the neurons so they could talk to each other better we have to also be taking something away so we are keeping the best of the best neurons we pruned away the ones that are dundon tor inefficient or not necessary and we improve the connections between the ones that we do keep and so you know this is where we start to think about  the true biology under underlying the speed versus accuracy tradeoff so when you're young you have a lot of areas of the brain that can fire as you get older there's really this move in a pattern for the brain to be more efficient so you use the best neurons available in the very good communicators so that's kind of the chief difference you could to age five your brain gets no bigger as you move into this second decade of life you have all this white matter that's improving your communication with at the same time you're pruning away the neurons that you don't need so at the end of that second decade of life you have this lean mean brain that is incredibly efficient and so with that comes the abilities that we hope that teenagers develop which are the abilities to become independent that's just amazing and the question i know to prune away the neurons or how does the know to make itself more efficient i mean as you alluded to there are things that are occurring you know that we don't know but there are people who do know on a cellular level how those things are occurring so you know it's exposure to the environment it's you know you we think about the use it or lose it type of idea if you start to learn an instrument you practice you strengthen those connections doesn't necessarily mean you lose other ones but we can certainly strengthen the pathways between them in probably one of the most notable things about the teenage period is that while a lot of the brain you know we know that in the first decade of life most of the brain is changing but in the second decade of life there are a lot of other parts of the brain that are also undergoing this reconstruction project but the most chief part of the brain that is changing during adolescence is the frontal lobe and so the frontal lobe is that area right behind the forehead and you know so this is where we now have the most important type of higher cognitive functioning so executive functions you know the one thing that i do know that adolescence means to grow up it's taken from some other word and it means to grow up it's what i did learn   like it doesn't know what it's supposed to be doing and it does know right from wrong but it's not going to do it so well what's going on there well so part of what we do in our lab you know we think of ourselves as under trying to understand the neurobiology of what were you thinking because when i talk to teenage audiences or parents i often ask them how many times if you are sad or bend the you know  receiving end of the what are you thinking so as you pointed out kids often know the right answers but parents are often puzzled by well if you do the right answer why didn't you do it and so part of that has to do with the machinery that's necessary to have good control over one's behavior so to step back for a second you point out that adolescence is a time to grow up so what does that mean evolutionarily it means that there is a part of the brain that is programmed for the offspring to leave the nest right so this is how they get away from home and make it in their own world and this is becoming independent and so there is a part of the brain that is actually program to seek out novelty to seek out new experiences to do things to be risk taking because that's what you have to do to kind of jump over that you know next step to become independent and so that was a brain is wired for novelty seeking and for risk taking the part that we know you know at least in the human species is that there are some aspects of risk taking that are dangerous drug use alcohol of any type of experimentation and so those are the parts of the brain that we're trying to understand number word of the impacts of dangerous types of behaviors on the adolescent brain and then who might be at greatest risk to kind of get involved in those types of things in so again it comes back to the frontal lobe so the  important for planning organizing executive functions but one of those abilities is the ability to have what's called response in the vision or cognitive control so you know i know very clearly that your name is pat and so why would i call you some other name well that's because my brain knows what the right answer is but for me to say the right answer i also have to simultaneously hold back all the wrong ones and so as you go through the second decade of life and as you navigate this adolescent period you may know the radio answer but the question is why did you do it so why well it's because the frontal lobe helps to put the brakes on impulsive behavior behavior that's not well thought out and so you know if we think about it we have a brain that's primed to go in age where a good percentage of young people become mentally ill and if there's something in that m r i that can show you that there may be a  pursuit of looking for things called biomarkers so aspects of the brain that might suggest who might be at risk or making comparisons between say someone who has depression and someone who doesn't when you talk about eighteen to twenty four when you think of that or that's collectively referred to as a period of emerging adulthood so this is a time when people are relatively adult they look like adults they have some adult abilities illegal and otherwise but they're not quite fully independent whether it's financially independent they're still in school and so what we're trying to understand as we used to we used to conventionally think that by the time you got to be eighteen that was it adult done good luck to you but one of the things we do know is that this period of adolescent brain development not only occurs in the second decade of life from ten to twenty it actually extends into emerging adulthood so some of that fine tuning that i talked about the frontal lobe finalization actually occurs into the early twenty's so twenty two twenty three twenty four so the brain is still vulnerable and one of the things i want to point out about the frontal lobe is that for example experimentation with alcohol or drugs absolutely impairs the ability for one to make a decision but if you have exposure to a substance that impairs your already not great ability to make decisions that is what we're interested in studying is what are the consequences of exposure to substances so alcohol and marijuana in particular because there has been a lot of change not only legally but also in terms of how harmful adolescents perceive marijuana to be in so what's really important here is that there is this biological process of brain development that's really impacted by exposure to alcohol and drug use the younger you use their younger you start to experiment the greater the likelihood of an addiction problem later in life like the kids in middle school that are using drugs already you know they're going to be using drugs alcohol  etc well some national studies have shown that if you start to initiate your first alcohol use at age thirteen there's a forty seven percent chance you'll have an addiction later in life and that number slowly decreases so the longer you can delay onset of use and that's part of our message is listen your brain is doing really important work and the longer you can delay the onset of use until your brain completes this very important process then the better off you will be and the safer you will be in the less at risk you will be in that it doesn't just hold for substance abuse it also holds for some mental illnesses because we know that you know early substance use can not only be a predictor of mental illnesses later in life but also can be a contributor sometimes people seek out substances as a way to self medicate some particular condition these are the things that we're trying to understand what are those risk markers in the adolescent brain so that we're pinpointing an age of adolescence we have a current study going on now we're recruiting thirteen and fourteen year olds who are healthy and we're going to study their brains over the course of three years now to come into the study they will not abuse alcohol or drugs they have not had any psychiatric symptoms but some percentage of those kids over the next three years will start to show some symptoms or will start to use and what we want to know is how does the brain predict who is at greatest risk for people film one i mean mclean hospital is number one in the country on research and it would be who for you you parents and your children to become part of a great study that this young lady is doing with her team and you mention that you have people coming from connecticut rhode island and nobody from belmont and it's right up the hill you know it's amazing and you are the director of the neural developmental laboratory on addictions and mental health at mclean and you're partnering with boston children's hospital center for adolescent substance abuse research on a research study to identify milestones of healthy adolescent brain development and the impact of alcohol use on this process now potential participants are not required to have used any alcohol or substances to be enrolled in the study the study will involve one study visit to  ean hospital per year i mean is that too much to ask for three years for an m r i brain scan now the only bad thing about an m r i brain scan is that makes a lot of noise so the noise will probably you complete a series of surveys and computer tasks and if you're eligible to participate you can receive up to three hundred dollars now any teen would like to get that you may be eligible to certain functions that if you are right handed your brain works a little differently than if your left handed we're actually going to be recruiting enough people that you know it's easier to look and people who are right handed because we look at one part of the brain and the other it probably wouldn't be a it's true that left handed people are extremely intelligent is that a myth that is a good question i know that there are differences depending on handedness there's also i think only ten percent of the population is left handed and at least from an imaging perspective most people typically don't recruit people that are left handed as well so we are probably missing a very important neural biological piece right this  let's talk about the teams that we've heard some really horrible stories about things that teens have done and these teens are they're not necessarily it depends on what you're looking at but the one positive aspect of m r i so we think about m r i we may think about it as being allowed or a big magnet it gives you in the same piece of machinery it gives you the ability to look at multiple aspects of the brain so if you look at the structure of your brain how many brain cells or how much white matter and gray matter you have you can also look at function of the brain so typically referred to as f m r i and so f m r i is usually when you have someone in the m r i scanner and you either have them looking in an image or you have them perform a task so in our particular study they come in and they actually get to do two fun computer tasks while they're doing in the m r i scanner and what that's telling us is that for you to be able to perform the task this is what part of your brain is required to be activating now probably not surprising i won't test you but look at probably guess what part of the brain we're most interested in looking at we're interested in that frontal lobe being able to put the brakes on we're also very interested in the memory center so we're interested in the hippocampus because we know that the frontal lobe in the hippocampus where we produce our memories are actually two of the most vulnerable parts of the brain to alcohol and drug use particularly when you're a teenager and so you know i often tell parents that there are a number of studies in animals that have shown that if you have adolescent an adult we know that adolescents are actually less sensitive to alcohol effects and are adults if you were to say now we wouldn't do this because of some of an ethical to give alcohol to human youth but if you were to have an adolescent and adult and you gave them the same amount of alcohol based on their body weight the adult would stagger from here to there you would know they were intoxicated the adolescent would walk from here to there and you wouldn't have any idea and that's because there are some aspects of the adolescent brain that are insensitive to some drug effects in so you know as an adult say you're having a cocktail you know that you're starting to get sleepy you know that you're starting to slur your words that is the feedback that we use to be able to say oh i've had enough it actually takes a teenager much higher blood alcohol levels to be able to reach that same level of intuitive feedback to say oh i've had enough and so that's where we kind of get into the danger zone kids are actually less sunset alcohol effects and other drug  effects but the part of the brain that is actually more vulnerable so i said that they're not as motor impaired but their memory their hippocampus is actually significantly more impaired so if you had the same teenager in the same adult and you give them the same amount of alcohol based on their body weight and you gave them a if we've knocked out kind of our ability to make sense or make good decisions one of the things we know is that as drivers we have to make second you know millisecond level decisions as we're driving and so one of the thing that's really affected even though the motor ability might not be impaired their reaction time is grossly impaired the ability to think about or to predict oh this car is coming over i need to think about the consequence of what's going to happen really goes offline so drinking and driving is really a big issue one other issue that's really been raised raised recently is that teens as i mentioned are finding that marijuana is actually not as risky so they're perceived harm or risk of marijuana as much lower so many teenagers will take the position that oh i would never drink and drive but i could use marijuana and drive in so you know that is just such a accurate precisely because marijuana does the same thing you know in in pairs our ability to make good judgment to make quick judgment and actually very much slow slows our reaction time but at the same time one thing that's important i've had a lot of parents ask me this so parents will say to me how can i rationalize sitting in having a glass of wine at dinner with my kids when you know i want them to know that this is not ok for them now i have young children i have a four year old and a soon to be two year old and they've already heard me talk about the fact that well you know my brain is adult we like to say i've reached neurobiological adulthood and so those substances are for  that's already developed and so that's one piece of thing the other thing that's important for parents to know is that the potency of marijuana in particular has really changed dramatically it's increased in potency at least four times in a since you know sixty's seventy's it's not the same marijuana before it pure form it's much higher levels of t h c which is the active ingredient in marijuana and so you know the marijuana that is available now now that kids have access to increasing access to is really much more harmful some of the other things we know is that you know it takes the adolescent brain longer to recover from one episode of use than it does the adult brain ok well we're going to have to continue this at some point because i want to but right now if  you only have about a minute so say something that you really want people bill want to know well and surrounding communities well i think the most important thing is we are really uncovering important aspects of how the teenage brain develops we know that we need to protect that brain so you know the second decade of life if you want to have a brain that lives on to seven eight nine decades it could very well be that protecting the teenage brain which means you know delaying the onset of alcohol use and delaying drug use as much as possible could perhaps you should find out about them and regarding depression regarding maybe elders and cetera so that's it for today and we'll be back soon and reza thank you so much i mean this is an education i had three girls and really i was really lucky but thank you and i'm sure all the parents up there thank you thank you and anybody can visit our website and learn more about our studies or