How the Benefits of Recovery Expand

by Julie Myers, PsyD, MSCP

Licensed Clinical Psychologist in San Diego;  http://www.DrJulieMyers.com

When you begin to contemplate changing your addictive behavior, you may think about all the problems that your behavior has caused.   There may be a single negative event (such as a DUI) or an accumulation of events and problems.  These problems may be enough to motivate you to change, but for sustained motivation, you may want to consider the positive change that may happen.

Try this simple exercise.  A cost-benefit-analysis¹  is a simple way to start thinking about the benefits of changing.   First, draw a line down the middle of a sheet of paper.  On the left side, list all of the benefits of your addictive behavior, for e.g., “It’s fun”, “It helps me sleep”, “It makes me more social”.   Now, on the right side, list all the negatives (costs) of using, for example “Hangovers”, or “My spouse is mad at me”, or “Legal issues”.   If your costs outweigh the benefits, you may be ready to change your addictive behavior.

Now, try expanding this simple exercise by adding two more columns on another page:  “Costs of Quitting” and “Benefits of Quitting”.   For example, costs may include losing friends or being bored.  The benefits may be something simple, such as “I’ll have more money”.

Something interesting happens the further you move forward in recovery:  The costs of quitting diminish.  Things that once seemed so important to you may lose their significance or you find new ways to satisfy your need.  For example, you may believe that you won’t have any way to calm yourself down, relax, or relieve your depression if you don’t use.  But as you learn to identify your thoughts, emotions, and behaviors, you will find new and more enduring ways to relax and deal with emotions.  Another commonly held belief is that you won’t have any fun, you will be bored.  But as the brain becomes accustomed to less intense rushes of dopamine (which most drugs of abuse and some maladaptive behaviors supply in overabundance), you will learn new ways to find enjoyment.

Even more interesting is how the benefits of stopping expand in unexpected ways.   The simple benefits of  “feeling better” or “having more time” lead to even more benefits.  For example, feeling better may mean that you feel good enough to enjoy the sunrise or climb a mountain.  You might not have predicted that you could find the time to go back to school, play basketball with your kids, or even read a book.  But the benefits of quitting are real, and in the end, more deeply satisfying than your maladaptive behavior.   As you move forward in your recovery, make note of all the things you discover that you can now do and enjoy, which you couldn’t do before.

¹For a great examples of this exercise, go to http://www.SMARTRecovery.org/resources/toolchest.htm

© (2011)  Julie Myers, PsyD

Cocaine and its Negative Side Effects

by Julie Myers, PsyD, MSCP

Licensed Clinical Psychologist in San Diego;  http://www.DrJulieMyers.com

 

As with other drugs, cocaine affects the nerve cells of the ventral segmental area, which extends into the nucleus accumbens, one of the reward centers of the brain.  Cocaine acts as a reuptake inhibitor of dopamine, whose increased presence creates the euphoria associated with cocaine.  The euphoric effects of cocaine are generally shorter acting than other drugs, lasting anywhere from a few minutes to a few hours, depending on the route of administration.  Because of its short duration, it is not uncommon for users to administer repeated doses (“binging”.)

In the short-term with small amounts, cocaine acts similarly to amphetamines, making the user feel euphoric, energetic, talkative, and mentally alert. It dilates pupils and increases vital signs such as temperature, heart rate, and blood pressure. With larger doses, the user can experience tremors, vertigo, and twitches.  A user may experience increasing irritability and restlessness.  Bizarre, erratic, and violent behaviors are associated with cocaine.  Chronic use can cause severe psychiatric symptoms, including anxiety, depression and psychosis.  Full-blown psychosis may result with paranoia, hallucinations, and delusions.

Medical complications associated with cocaine use include cardiovascular effects.  “Cocaine causes the blood vessels to thicken and constrict, reducing the flow of oxygen to the heart.  At the same time, cocaine causes the heart muscle to work harder, leading to heart attack or stroke, even in healthy people” (CAMH, 2007.)  It raises blood pressure, which can explode the weakened blood vessels in the brain.  It may also cause abdominal pain, nausea, and blurred vision.

As with other drugs, the route of administration can produce different adverse effects. Snorting cocaine can cause nasal effects, including loss of sense of smell, nosebleeds, problems with swallowing, hoarseness, and an even a perforated nasal septum.  Ingested cocaine can cause severe bowel gangrene, due to reduced blood flow. Smoking cocaine can cause “crack lung”, which includes severe chest pain and breathing problems.

When cocaine is mixed with alcohol, the two drugs are converted by the body to cocaethylene, a cocaine metabolite.  Cocaethylene appears to have more cardiovascular toxicity and hepatoxity than either drug alone.

Even though a user becomes tolerant to cocaine, they may not become sensitized to its anesthetic and convulsant effect, which may explain some cocaine deaths.  Overdose can cause seizures, heart failure, and arrest breathing. Withdrawal can include exhaustion, sleepiness or sleeplessness, hunger, irritability, depression.  Cocaine has a small index of tolerability.

 – Julie Myers, PsyD, MSCP    (www.DrJulieMyers.com)

The bulk of the information for this article was taken from NIDA (2004) and CAMH (2007.)  These resources offer a wealth of up-to-date information about the different drugs of abuse and are one of the first places to look for the most current information about any drug. I urge you to check out these resources for the latest information on addiction.

References:

CAMH (2007), Centre for Addiction and Mental Health, Do You Know… Cocaine

Castane, A., F. Berrendero, & R. Maldonado (2005), The role of the cannabinoid system in nicotine addiction Pharmacol Biochem Behav. 81(2), pp. 381-6.

NIDA (2004), NIDA Research Report – Cocaine Abuse and Addiction: NIH Publication No. 99-4342..

NIDA (2006), Research Report – Tobacco Addiction: NIH Publication No. 06-4342.1346417

Picciolo, M., D. Gigante, & A. Nunziata (2005), Nicotine addiction and current therapy of smoking cessation Clin Ter. 156(4), pp.159-71.

The SMART Recovery® Activities Scale (SRAS)

by Julie Myers, PsyD and Donald Meichenbaum, PhD

The SMART Recovery^® Activities Scale (SRAS) is a new tool to help those engaged with SMART Recovery^®.   The SRAS was developed by Julie Myers, Psy.D.¹ and Donald Meichenbaum, Ph.D.²   

The SRAS can be used by participants to assess how far they have come in their own recovery, by facilitators, and by professional therapists/counselors with their clients.  Professionals may wish to use the SRAS in order to:

1. Assess what SMART Recovery^® activities clients have already engaged in and what SMART Recovery^® beliefs they have embraced.
2. Assess the reasons why clients have or have not engaged in these activities (possible barriers, lack of motivation, confidence, or skills) and how these obstacles can be addressed.
3. Engage would-be participants to join SMART Recovery^® and treatment, highlighting what new members may get out of some form of treatment

The SRAS for participants is available on-line in an easy-to-use PDF format, which can be filled-out on-line or can be saved and printed.  (http://www.smartrecovery.org/resources/library/Tools_and_Homework/Quick_Reference/SRAS_for_participants.pdf ) 

 The SRAS for therapists/facilitators containing additional instructions is available at http://www.smartrecovery.org/resources/library/Tools_and_Homework/Quick_Reference/SRAS_for_therapists.pdf

Dr. Meichenbaum and Dr. Myers are seeking feedback about your experience with the SRAS.  Your feedback is greatly appreciated, as it will help to refine the scale and  help develop other SMART Recovery^® materials that will have wide distribution throughout the world.  Please direct your e-mail to Julie.Myers100@gmail.com.
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¹ Dr. Myers is a Licensed Clinical Psychologist in San Diego, California

² Dr Meichenbaum is one of the founders of Cogntivie Behavior Therapy and is presently Research Director of the Melissa Institute for Violence Prevention in Miami ( www.melissainstitute.org)

Assumptions About Substance Abuse: An Opinion

by Julie Myers, PsyD, MSCP

Licensed Clinical Psychologist in San Diego;  http://www.DrJulieMyers.com

 

There are many different models of addiction, including moral, psychological (cognitive-behavioral, learning, psychodynamic, and personality), biological (genetic, biomedical, disease, medical) and socio-cultural (McNeese, 2005.)  Each of these different models operates under a different set of assumptions.  The disagreement between the models rests on the different political motivations, ideologies, personal interests, and professional training of the individual (McNeese, 2005.)  Substance abuse counselors, for example, have generally adopted the 12-step approach to the disease model, since it is what they themselves experienced.  Probably the most commonly held is the disease model. “The disease model of addiction rests on three primary assumptions: a predisposition to use a drug, loss of control over use, and progression” (Krivanek, 1988, p. 202.)  It has its roots in Alcoholics Anonymous (Yalisove, 1998.)

The World Health Organization has adopted the word drug dependence to describe the addiction process. “The general term (drug dependence) will help to indicate a relationship by drawing attention to a common feature associated with drug abuse and at the same time permit more exact description and differentiation of specific characteristics according to the nature of the agent involved.” (WHO, 1964.)

Perhaps the stress-diathesis model best describes substance abuse, dependence, and addiction.  This model describe a basis of genetic and neurological susceptibilities to addiction, either because of the genetic susceptibility to the substance (or behaviors) or because of the genetic susceptibility to certain mental disorders, which increases the likelihood of self-medication and the abuse of substances (or behaviors.)  For example, those with Bipolar
Disorder have a 50-80% increase in substance abuse, which is thought to be largely self-medication. Given a person’s susceptibility, the environmental factors then influence whether or not any one individual develops a problem with substances (or behaviors.)  Upbringing, peers, experiences, and culture all shape one’s use of substances.  How the individual responds and copes with environmental stressors in large part determines their use.  Addictions represent a maladaptive coping mechanism to these environmental stressors.

It may not be necessary to know the etiology of substance abuse to treat it.  Although such information is interesting scientifically, and it can perhaps lead to better identification of susceptible individuals, treatment should concentrate on identifying those individuals with addictive problems and implementing effective treatment.  The identification of addiction problems can be culturally influenced.  Although the scope of the problem throughout the world is massive, the definition of it as an “addiction”, “abuse” or “dependence” must be understood in light of cultural norms.

The DSM-IV (APA, 1994) defines substance abuse and dependence as:

• Substance Abuse is a maladaptive pattern of substance use which results in clinically significant impairment, with one (or more) categories occurring within a 12 months:  failure to fulfill major obligations, use in hazardous situations, legal problems, or social problems.
• Substance Dependence is a maladaptive pattern of substance use, which results in clinically significant impairment, with three (or more) categories occurring in the same 12 months: physical tolerance, withdrawal symptoms, a large amount consumed over a long period, a lot of time spent, negative consequences, and continued use despite recurrent problems.

Although the DSM criteria states that three criteria must be met, in my opinion, for any particularly individual, simply displaying one of these criteria could signify abuse/dependence.   For example, continued use, despite knowledge of significant problems may be enough to signify that there may be an addictive disorder.  Setting the criteria for dependence as three/five criteria may be necessary for those individuals for whom there is less clear evidence of maladaptive behaviors.

– Julie Myers, PsyD, MSCP

Licensed Psychologist, MS Clinical Psychopharmacology, Master Addiction Counselor, Board Certified Biofeedback  http://www.DrJulieMyers.com.  

Copyright (2011):  Julie Myers, PsyD.  All Rights Reserved

———————

APA.  (1994).  Diagnostic and Statistical Manual of Mental Disorders, 4th Edition. Washington DC: American Psychiatric Association.

Bergh, C., T. Eklund, P. Sodersten, & C. Nordin (1997).  Altered dopamine function in pathological gambling.  Psychological Medicine, 27: 473-475.

Doweiko, H. (2006). Concepts of chemical dependency. 6th ed. Belmont, CA: Thompson .

Goudriaan, A., J. Oosterlaan, E. de Beurs, & W. Van Den Brink (2004). Pathological gambling: a comprehensive review of biobehavioral findings.  Neuroscience & Biobehavioral Reviews.  28(2), pp.123-141.

Krivanek, (1988), p. 202., Addictions.  Sydney: Allen & Unwin.)

McNeese, C. & D. DiNitto (2005).  Chemical Dependency. United States: Pearson Education, Inc.

Sunderwirth, S., &H. Milkman (1991). Behavioral and neurochemical commonalities in addiction, Contemporary Family Therapy , 13(5 ) pp. 421-433

WHO (1964), Expert Committee on Addiction-producing Drugs: Thirteenth report, p. 53 -55.

Yalisove, A. (1998). The origins and evolution of the disease concept of treatment.  Journal of Studies on Alcohol, 59, 469-476.

Brain, Behavior, and Drugs

Brain, Behavior, and Drugs

By Julie Myers, PsyD, MSCP

http://www.DrJulieMyers.com

I.  The complex and adaptive brain

1. Brain architecture:  gross anatomy, neurons
2. How the brain communicates
3. Adaptation and learning

II.  How drugs hijack the brain

1. Pleasure and the reward center:  the dopamine connection
2. What (or who) controls the reward center?:    bottom-up vs. Top-down
3. Brain adaptation:   the change from use to abuse
4. Binge, withdrawal, cravings, relapse, and the role of stress hormones
5. Medication that can change the brain’s response

III:  Is addiction biology or just a bad habit?  The possibilities of change

I.  The Complex and Adaptive Brain

The brain is an extraordinarily complex organ.   Once thought to be essentially static after adulthood, we now know that the brain continues to adapt and change and even to grow new neurons.   This is important, as the formation and maintenance of addictive disorders depends not only on the environment, but on the molecular, genetic, and cellular adaptations of the brain.  Addiction to drugs follows a pattern of spiraling brain dysfunction, similar to that seen with gambling, compulsive exercise, binge eating, etc.  Let’s now look more closely at the structure of the brain itself in order to understand the way it processes information and how we become addicted.

A.  Brain architecture

Gross Anatomy:  The brain lies nestled inside the protective skull, surrounded by the blood brain barrier, a filter that selects which chemicals/drugs to allow into the brain.  The largest part of the human brain is the cerebrum, and it is composed of four lobes (areas), each with their own specialization.   The outermost part of the cerebrum is the cerebral cortex, the part of the brain responsible for higher-order thinking.  The prefrontal cortex is in the front part of the cerebral cortex; it controls judgment, decision making, and emotional regulation.  Other structures of the brain important in addiction are the limbic system (made up of the hippocampus, and amygdala), ventral tegmental area (VTA), nucleus accumbens, and dorsal striatum.

Neurons:  Within the brain structures are clusters of neurons (nerve cells) called nuclei that govern specific brain processes.  They form routes that allow one part of the brain to communicate with another;  integrating, processing, interpreting, storing, and distributing information.  A neurons is made up of the cell body, axon, axon terminal, dendrites, and dendritic spines.  The neurons are separated by one another by a space called a synapse.

PICTURE

 

Within the axon terminal are small containers (vesicles) that store the brain chemical messengers called neurotransmitters.  Located on the dendrites are special proteins called receptors, which absorb the neurotransmitters into the cell.  Each receptor specializes in a particular chemical neurotransmitter.  The two most common neurotransmitters in the brain are glutamate and gamma-aminobutyric acid (GABA).  Drugs of abuse act on glutamate and GABA, but also on other neurotransmitters such as serotonin, norepinephrine, acetylcholine, and most importantly dopamine.

B. How the brain communicates

The brain does not act by a single process, but rather by millions of communication pathways made up of neurons and nuclei.  Neurons communication with one another via neurotransmission, which is carried out by the neurotransmitters   To better understand this communication, let’s first examine serotonin, a neurotransmitter important in the drug ecstasy.

Serotonin is synthesized within the neuron body and is stored in vesicles at the axon terminal.  When the neuron receives a signal to release serotonin, the vesicle moves to the interior membrane of the neuron (presynaptic membrane).  The vesicle fuses with the presynaptic membrane, releasing its contents into the synapse.  Once in the synapse, the serotonin travels to the dendritic spine of the receiving neuron, attaching to serotonin receptors.  It is then taken up into the cell by reuptake pumps, reducing the concentration of serotonin in the synapse.

In the receiving neuron, the serotonin may act to activate or inhibit enzymes, release ions, turn-on genes, or increase cyclic adenosine monophosphate (cAMP), which generates the neuronal electrical impulses that propagate communication through the nerve.  When an electrical impulse is generated, it travels down the axon toward the axon terminal, stimulating release of neurotransmitters from vesicles, which are then released to the next neuron to continue the communication pathway.  The electrical impulse transmission is very rapid, but transmission may also occur more slowly, particularly when hormones are stimulated for released by neurotransmitters.  As we will examine later, when drugs of abuse enter the brain, this delicate communication pattern is disrupted.

 

C.  Adaptation and Learning

The brain is able to adjust to both internal and external stimuli by forming new neuronal connection and by decreasing or increasing receptors, neurotransmitters, dendrites, and hormones.  This ability to adapt (neuroplasticity) helps to explain not only how we become addicted, but how we may unlearn addiction.  It even gives some hope for the possibility of the brain repairing itself from structural damage caused by drugs.

The brain responds to stimuli by generating new neuronal pathways.  For example, if you practice hitting a baseball, you become more skilled as the brain grows new dendritic spines and synapses, transmitting the learned sequence most efficiently.  Neurotransmitters decrease or increase to support this new structure.  The more the pathways are used, the more efficient they become and the stronger the neuronal connections become;  the less they are used, the more the skill (or habit) fades.  Habits can form from any repetitive action that stimulates the brain, such as checking our e-mail or drinking coffee.  Habits, particularly using drugs of abuse, involve the body’s natural hedonic reward system, or reward center.

II.  How drugs hijack the brain

The brain maintains an internal equilibrium by adjusting its structure and function to maintain homeostasis  (maintenance of normal body equilibria).  Although highly adaptive, when drugs of abuse enter the system, homeostasis can be disrupted.   Depending on the quantity, route of administration, and length of time the drug is used, disruption may be profound.   Drugs may come to dominate – or hijack – normal brain function, particularly in the reward center of the brain.

A. Pleasure and the Reward Center

We are hedonistically programmed to seek pleasure.  When the neurotransmitter dopamine is released into the brain, we experience it as pleasure.  Many things release dopamine, including natural highs like exercise, socializing, and sex, as well as all drugs of abuse.  Dopamine plays a dominate role in the reward center, which is controlled by the mesolimbic dopamine pathway.  This pathway starts in the VTA and connects to the limbic system.  The prefrontal cortex, our decision making center, is also involved in this pathway.

PICTURE

The mesolimbic dopamine pathway mediates pleasure using an array of natural chemicals, including endorphins (like morphine), anandaminde (like cannabis), acetylcholine (like nicotine), and dopamine (like cocaine/amphetamines).  When released naturally from neurotransmitter processes, these chemicals help regulate our mood and behavior and bring us pleasure.  However, when drugs of abuse are introduced, they hijack this system, bypassing our body’s own neurotransmitters and directly stimulating an explosive and large release of dopamine.  Such a large and quick release of dopamine dwarfs our natural hedonistic drive to seek pleasure from more sustainable, but smaller sources of dopamine.

Although all drugs of abuse result in a release of dopamine, they may also affect other neurotransmitters.   Cocaine works by a fairly simple mechanism:  It blocks dopamine transporter pumps from taking dopamine up into the neuron, thus increasing dopamine in the synapse.   Opiates affect the reward system via dopamine indirectly:   Opiates bind to a receptor, causing dopamine to be released, which then affects a nearby neuron containing GABA, which inhibits dopamine release thus increasing dopamine release.  Ecstasy binds to the serotonin transporter first, preventing transport and reuptake, which then increased serotonin is in the synapse,  causing activation of serotonin and dopamine receptors.

B. What (or who) controls the Reward Center?

Control of the mesolimbic dopamine pathway occurs at two levels:   Bottom-up control (originating at the level of stimulation) and top-down control (originating from brain cortical regions)

Bottom-up control

The amygdala — the area of the brain involved with memory and emotion – is connected to the mesolimbic dopamine pathway.  When a potentially pleasurable activity or substance is received (e.g., drugs), the amygdala signals neurons in the VTA and the nucleus accumbens.  Dopamine is released, and the stimulus is interpreted as pleasurable;  it becomes a “reward”.   The structures involved with this pathway “learn” that pleasure is created when the drug is introduced into the system.  The amygdala stores the “memory” of the drug, as well as associations of that drug, e.g., paraphernalia.   The brain learned how to acquire fast and large quantities of dopamine.  This reward-learning can be so powerful that the brain can forget how to acquire pleasure through natural engagement in everyday activities.  In essence, normal learning is short-circuited.

When we learn that a particular stimuli (reward) gives pleasure, it positively reinforces the behavior that produced it.  Positive reinforcement occurs on a small scale for everyday things we enjoy, for example, if we enjoy someone’s company, we seek them out.  Our choice to engage in repeated, pleasurable behaviors usually has a direct relationship to the amount of dopamine released.  Depending on individual brain make-up, drugs of abuse can be an extreme form of positive reinforcement (as may some activities such as sex, gambling, and food), driving us toward more drug seeking behavior.

The reward pathway for a particular stimuli can become so strong and automatic, that even when the stimuli is not so rewarding – or when there may be dire consequences – we continue to seek the stimuli.  Cravings arise out of these automatic pathways; the stronger and more fixed the pathways, the stronger our desire to seek the drug (reward).  Memory of the drug is stored in the amygdala, and when it receives information about the drug or its associations, it activates the reward system, triggering the neurons in the nucleus accumbens to procure that drug to seek pleasure.  The more we have used the drug and derived pleasure from it, the stronger will be the drive to complete the reward cycle.

Top-down control

Luckily humans possess a thinking brain, allowing interpretation and interruption of the automatic bottom-up pathway.   At the top of the reward center is the prefrontal cortex, which regulates impulse, analysis, flexibility, and integration of emotions.  At this level of reward center control, we are able to consciously make decisions to use (or not use) quick, dopamine releasing drugs or activities.  The strength of our top-down control system to override the impulses of the bottom-up control depends on our experience, our genetics, our learning about the benefits and cost of our decisions, and our ability to self-regulate.  It is this top-down control that is ultimately at the core of drug abuse treatment, which relies on the strengthening of the top-down control system to interrupt and reclaim bottom-up control.

C.  Brain Adaptation:   The progression from use to abuse

The neuroplasticity of the brain contributes to the progression from casual drug use to addiction.  Drugs of abuse cause short and long-term adaptation in a predictable succession (Koob, 2010), starting with the (1) mesolimbic dopamine pathways, moving to the (2) ventral striatum, (3) ventral striatum/ dorsal striatum/thalamus  (4) dorsolateral frontal cortex/inferior frontal cortex/hippocampus system, and finally the (5) extended amygdala.  This neuroadaptation reprograms the systems that process reward, motivation, memory, habituation, decision making, inhibition, self-awareness, and stress reactions.   This reprogramming leads to dysregulation of the brain reward center, causing compulsive drug use and loss of control.

 

Short-term change

All drugs of abuse have an immediate action on neurotransmission, particularly dopamine.  The opiates mimic neurotransmitters, which mimic dopamine.  Benzodiazepines enhance the receiving cells response to dopamine.  Cocaine hijacks the dopamine receptors, so that dopamine is not taken out of the synapse, and marijuana mimics cannabinoid neurotransmitters.  Other drugs alter neurotransmission by interacting with or interfering with the neurotransmission signals.  The quantity of drug taken, the metabolic breakdown of the drug, and route that the drug is taken all affect the strength of the dopamine reward (the faster the administration, the strongest reward).  The dopamine release is more prolonged and unregulated than natural stimuli, and the reinforcing effects from such large increases in dopamine in the brain affect the reward threshold.

 

Long-term change: 

As drug use continues, long-term structural changes occur in the brain, some of which may be permanent.  Simple structural changes include the up-regulation or down-regulation of receptors.  Up regulation means that when the neurons is exposed to too little neurotransmitter, more receptors are created to “capture” neurotransmitters in the synapse.  Down-regulation refers to the process where the number of receptors is reduced when exposed to too much neurotransmitter (or drugs mimicking the neurotransmitter).

Down regulation is especially important when drug use is stopped.  When a drug is actively being used, a lot of dopamine is in the synapse;  receptors down-regulate to adapt to the abundant dopamine.  If the drug is then stopped, less dopamine is available but few receptors are present.  Since neurons can’t up-regulate instantaneously, withdrawal symptoms are felt because of the relative reduction in dopamine.

More serious structural changes occur when drug use results in neuron death or loss of function. Neuroimaging of the brain (such as CAT scans or MRI) shows that some drugs can cause loss of brain structure and function.  Such loss may be caused by over-excitation of the neuron, which leads to apoptosis (cell suicide), and direct toxicity to the cell or dendrite.   Sometimes the brain can regrow dendrites, reversing drug damage and allowing the brain to return to normal;  in some cases damage is irreversible.

Most important of the long term adaptations is the change in the mesolimbic dopamine pathway, caused by dopamine that is released in a more prolonged and unregulated manner than natural stimuli.  The brain no longer responds to lower, slower levels of dopamine.   In other words, there is a recalibration of dopamine-activating (reward) thresholds for natural reinforcers.  This low dopamine tone contributes to the lack of motivation often seen in those using drugs.

The ability to choose between small, immediate rewards and large, deferred rewards is made in the prefrontal cortex.  With drug use, adaptations occur in the regulation of cognitive and emotional processes, which results in the overvaluing of drugs and the undervaluing of natural reinforcers.  There are deficits in inhibitory control of drug responses and an overall underperforming of the prefrontal cortex leading to poor impulse control.   With chronic drug exposure, the neurons responsible for memory and conditioned learning undergo abnormal neuroadaptations.

Binge, withdrawal, cravings, relapse, and the role of stress hormones

Each stage of the addiction cycle – binge, withdrawal, and cravings – is controlled by discrete brain system (Koons, 2010).  These systems play a role in developing and maintaining an addiction and they also contribute to relapse.

During the binging stage, the ventral tegmental area and the ventral striatum of the forebrain play dominate roles.  The acute reinforcing effects of drugs depends on immediate neurotransmitter release.  Impulsivity (the rapid, unplanned reactions to stimuli without regard for negative consequences) is the dominate behavior when a person first starts using drugs and is controlled by these brain areas.

With continued drug use, both compulsivity (repeated behavior in the face of adverse consequences) and impulsivity play roles in maintaining the addiction.  During the withdrawal stage, compulsivity changes from a behavior leading to positive reinforcement (i.e., the high of the drug use) to a behavior with negative reinforcement.  Negative reinforcement refers to the removal of an aversive stimulus, i.e., the removal of the negative emotional state that comes with withdrawal.   The negative emotional mood state is caused by decreased neurotransmitters:  Decreased dopamine and serotonin leading to dysphoria,  decreased opioid peptides causing pain, and decreased GABA, which results in anxiety and panic.  The extended amygdala, which plays an important role in pain and fear/stress processing, dominates the withdrawal stage.

Acute withdrawal is drug specific, but all drugs of abuse increase the stress response from release of stress hormones such as corticotropin releasing factor (CRF).  Dopamine is low in post-acute withdrawal, which increases sensitivity to environmental cues and decreases sensitivity to reward.   Changes in the prefrontal cortex follows, with impaired control of impulsivity.  The decrease in the reward system and the increase in stress sensitivity persist in post-acute withdrawal and play a role in relapse.

The preoccupation(cravings) stage is controlled by an variety of brain systems, including the prefrontal cortex, amygdala, and hippocampus.  Brain stress systems play a key role in the cravings stage, particularly from actions of CRF and norepinephrine in the extended amygdala.   Combined dopamine and glutamate neurotransmission in the dorsal striatum (involved with habit formation and action initiation) is involved when cravings, which are triggered by stimuli from external environmental cues and internal mood states of anxiety, irritability, and dysphoria.

Medication that can change the brain’s response

Research on ways to inhibit cue-conditioned dopamine and glutamate responses is a focus of current development of medication to treat addictions.   Treatments for binging and cravings include naltrexone (ReVia, Vivitrol), buprenorphine (Suboxone, Subutex), varenicline (Chantix), nicotine replacement, and methadone.  Treatments for negative mood state and cravings include methadone (Dolophine), buprenorphine (Suboxone, Subutex), varenicline (Chantix), nicotine replacement, acamprosate (Campral), and bupropion (Zyban).   There is optimism in the scientific community about the possibility that new drugs will be developed, which may help individuals gain and maintain control over addictive behaviors and substances.

III:  Is addiction biology or just a bad habit?  The possibilities of change

To what extent does genetics control the propensity to develop an addiction?   It has been shown that genetic factors, the environment, and the non-shared environment all had nearly equal influences on an individual’s risk of developing a drug use disorder (Tsaung, 1996).  There are also appear to be genetic and environmentalcharacteristics that make up a common vulnerabilityto abuse a range of illegal drugs (Tsuang, 1998).  That is, abuse of one drug is associated witha marked increase in the probability of abusing every othercategory of drug.  Also, drugs may “turn-on” genes to produce proteins, which cause changes in cell function or structure, which may lead to neuroadaptations.  Cocaine, for example, causes genes to produce the proteins necessary for new dendritic growth, and those who abuse alcohol are more likely to have different  dopamine receptor genes (Smith, 1992).

From scientific studies, we know that certain genetic factors may play a role in the development of an addiction;  some people may simply be more predisposed to developing an addiction.  We also know that in the development of addiction, there is a spiraling dysregulation of brain reward systems, producing short and long term changes in the brain.  Changes include both structural and functional changes in the brain, which reinforce the response to conditioned cues and maintain cravings, strengthened by the development of a stress sensitivity.   But does this mean that some of us are “programmed” to use drugs and that their use is predestined by genetics?  No.

We know that people do stop using drugs.   How do they do this if they are programmed to use the drug genetically or environmentally?  They change, because when stopping the drug becomes more important to them than continuing the drug, they can override and overcome the impulses generated by brain adaptations that maintain the abuse.   They are able to reengage the more sophisticated top-down control of the brain, overriding the bottom-up control of the more primitive parts of the brain.    Simply stated, we as humans are able to choose.

Julie Myers, PsyD, MSCP

Licensed Psychologist, MS Clinical Psychopharmacology, Master Addiction Counselor, Board Certified Biofeedback  http://www.DrJulieMyers.com.  

Copyright 2011 Julie Myers, PsyD.  All Rights Reserved

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