Making Memories, Our Living History

The Reward Pathway

 Amygadala

• The NA connects to the Amygadala.
• This part of the brain stores our memories and plays a major part in fear.
• This section is responsible for flight or fight.
• Those who suffer from PTSD or Anxiety Disorders have abnormal activity in this section of the brain.
• The pleasurable memories of drug use are stored in this part of the brain.
• It causes the addict to forget the negative consequences associated with chemical use which results in relapse.

Addiction is driven by pleasure and not by the relief of withdrawal. When I discovered this concept, I was really surprised especially with those addicted to opiates. I always thought it was about avoiding the painful effects of withdrawal.

• Pleasure is due to the release of dopamine.
• Seeking of pleasure in order to feel well vs. unwell.
• Those in rehab tend to increase cigarette smoking and eating because dopamine levels have dropped once the person stops the use of drugs and alcohol. Smoking and eating increase the dopamine levels.
• If addiction was all about the relief of withdrawal than detox would be enough treatment.
• 95% of those who leave treatment after detox and do not stay for rehab will relapse in the first year.

This is an important fact, I teach in the Addictive Brain class on Tuesday mornings. Many of the patients, I encounter think detox is enough only to discharge and return a short time later. My greatest challenge is getting insurance companies to recognize this fact. Most insurance companies want to fund detox and have the patient discharge to IOP (Intensive Outpatient). This sets a patient up for failure. Only after the patient fails in IOP will the insurance company consider rehab. This is a dangerous game to play when the life of a person is in the balance. The next drug run could be their last.

The Reward Pathway

• Most addicting drugs bind to receptors on the neurons of the Ventral Regmental Area (VTA).
• The axons of the VTA connect with the nucleus accumbens (NA), the pleasure center.
• Drug or alcohol use results in a release of dopamine into the NA resulting in euphoria.
• The NA has neurons that extend to the frontal lobes and the amygdala.

Some interesting facts that I now consider when working with my younger patients.

• The frontal lobe does not fully develop until the age of 25, therefore relapse rates increase in this age populations.
• Addicting drugs over ride the pleasure center creating tremendous release of dopamine in the NA.
• Normal survival behaviors occur in the NA such as sex, eating and drinking to sustain life.
• When drugs or alcohol are introduced into the NA, they become more important to essential living than sex, eating or drinking.
• The amount of dopamine in one's brain is genetically mediated.
• This results in a greater amount of dopamine released when an addict uses alcohol or opiates compared to the non-addict who uses alcohol or opiates.
• It is important to realize that gambling, porn addiction overlaps with substance addiction. Over 50% of those with one addiction have a second addiction. 

The Brain as an Obstacle for Recovery

Neuron Communication

• The neuron sends an electrical signal down its axon.
• At the end of the axon, a chemical messenger is released in the synapse.
• The chemical messenger then binds to a specific receptor on the receiving neuron.
• These chemical messengers are known as neurotransmitters.

There are seven neurotransmitters which I will review today.

Gaba (Gamma-Aminobutyric Acid)

• Binds to Gaba receptors.
• Receptors are the same receptors Benzodiazepines and alcohol binds to.
• Is a naturally occurring sedative neurotransmitter.
• Low levels of Gaba is believed to be part of the cause for anxiety disorders.

Glutamate

• Binds to Glutamate receptors.
• Naturally occurring stimulatory neurotransmitter..
• It is also an amino acid.

The imbalance between Gaba and Glutamate results in dysphoria and drug cravings. Medications may help to restore this imbalance.

Endorphins and Enkephalins

• These are our natural opiates or pain killers.
• Binds to opiate receptors the same way heroin, morphine and oxycodone binds to.
• The chronic use of opiates results in the suppression of endorphins leading to the symptoms of opiate withdrawal including poor pain tolerance and a lack of the sense of well being.

Serotonin and Norephinephrine

• Low levels of either of these neurotransmitters results in the symptoms of depression.
• Depression is the result of a defect in the genetic code responsible for the production of these neurotransmitters.
• Chronic drug and alcohol use lowers the levels of these neurotransmitters resulting in the depression like symptoms of early recovery known as PAWS (Post Acute Withdrawal Symptoms).
• Ecstasy can cause cell death and destroy serotonin levels after just one use.
• Genetic vulnerability to mental health diagnosis and addiction problems.

Dopamine

• Is a neurotransmitter as well as a hormone.
• Plays many different roles in different areas of the brain.
• When there are low levels can result in Parkinson's Disease.
• When there is high levels can result in hallucinations and Schizophrenia.
• Called the "feel good" chemical in the reward pathway that is released when drugs are taken.

Endocannabinoids

• Recently discovered neurotransmitter.
• Binds to the same receptors as THC.
• Plays a role in hunger.
• Being researched to see if they can benefit weight loss and quit cigarette smoking.

I hope you enjoyed Part I of the series by Dr. Christopher Davis. Part II coming soon known as The Reward Pathway.