REWARD DEFICIENCY SYNDROME:

The Science of Addiction

Addictive, impulsive and compulsive disorder-including alcoholism, attention-deficit disorders, drug abuse and food

binging-may have a common genetic basis.

Scientists: Kenneth Blum, John G. Cull, Eric R. Braverman, and David Cunningham

Topics for Discussion What is the reward deficiency syndrome?

What is the biology reward?

What is addiction? Dependency?

Addiction of Alcoholism

Addiction of Drug Use & Smoking

Addiction of Attention-Deficit Disorder

Treatment?

Unexplained results & Conclusion………

Neuroadaptation: Skinner’s Rat

Biology Of Reward

The Pleasure and reward system “discovered” by Psychologist James Olds in 1954: placed electrodes in the limbic system of Rats, who stimulated themselves unstoppably. Research was continued on humans and further experimentation revealed that the electrical stimulation of medial hypothalamus produce a feeling of quasi-orgasmic sexual arousal. Further conclusive research on dependency of drugs such as opiate, cocaine, and alcohol have rely on common biochemical pathways that include the neuronal pathway that involve the limbic system, the nucleus accumbens, and the globus pallidus.

Reward-Deficiency Syndrome -Disruption in the normal excitation and inhibition of these intracellular

interactions that result into other feelings such as anxiety, anger, stress, and CRAVING for the substance.

Factors: Addiction and/or chemical dependency

Reward & Other Pathways:

Pain Pathway

First, nerve endings in the finger sense the injury to the finger (sensory neurons) and they send impulses along axons to the spinal cord (magenta pathway)

The incoming axons form a synapse with neurons that project up to the brain.

The neurons that travel up the spinal cord then form synapses with neurons in the thalamus, which is a part of the midbrain (magenta circle).

The thalamus organizes this information and sends it to the sensory cortex (blue), which interprets the information as pain and directs the nearby motor cortex (orange) to send information back to the thalamus (green pathway).

Again, the thalamus organizes this incoming information and sends signals down the spinal cord, which direct motor neurons to the finger and other parts of the body to react to the pain (e.g., shaking the finger or screaming "ouch!").

NATURAL REWARDS:FOOD, SEX, WATER,

NURTURING (right image)

Needed for the survival of the respective organism to ensure that the action will be repeated.

ADDICTION VS DEPENDENCEDEPENDECE:STATE IN WHICH THE ORGANISM FUNCTIONS

NORMALLY ONLY IN THE PRESENCE OF THE SUBSTANCE DUE TO COMPULSIVE USE AND WITHDRAWAL SYMPTOMS.

ADDICTION: INDIVIDUAL ENGAGES IN COMPULSIVE BEHAVIOR

IN ORDER TO SELF-ADMINISTER REWARDING OR PLEASURE. SUCH INDIVIDUAL LOSES CONTROL OF INTAKE AND BECOMES

DEPENDENT.

Addictive Drugs Activate the Reward System Via Increasing Dopamine (D2) Neurotransmission

REWARD DECICIENCY SYNDROME

Addictive behavior

Severe Severe alcoholismalcoholism

PolysubstancPolysubstance abusee abuse

smokingsmoking

obesity

Impulsive behavior

ADHDADHD

Tourette Tourette SyndromeSyndrome

Autism

Personality Disorder

Conduct Disorder

Antisocial Disorder

Aggressive Behavior

Compulsive Behavior

Aberrant Sexual Behavior

Pathological Gambling