Dopamine, a neurotransmitter in the brain, plays a role in how you feel and has been linked to addiction and pleasure, according to Mayoclinic.com, as well as focus and memory. Although exact causes of obsessive compulsive behavior, OCD, are unknown, abnormal levels of dopamine are linked to the disorder. Dopamine imbalances are also associated with reward-seeking behavior and addictive tendencies, which may also be considered compulsions.
Neurotransmitters and Receptors
Neurotransmitters are chemicals used by the nervous system to cause your body and mind to react in a specific way. The nerve endings in your brain do not touch but are actually separated by a space called a synapse. Nerve impulses travel these synapses via neurotransmitters. Depending upon signals from the brain, a specific neurotransmitter is released from one side of the synapse and connects to a specific site, called a receptor, on the other side. Once the neurotransmitter is plugged into the receptor, which is custom-made for that neurotransmitter, its message is transmitted. These messages can trigger emotions and feelings as well as muscle movement and physical reactions. If there is an inadequate amount of neurotransmitter or if its receptor sites are blocked or damaged, the brain's messages cannot be conveyed properly. Dysfunction in the body and brain can result.
Dopamine
Dopamine is an important neurotransmitter without which your memory, movements and desire to try new things will be impaired. According to KCI.org, dopamine is a fundamental part of your brain's control over your body's movements. Deficiencies in dopamine can lead to a lack of control, potentially causing shaking or the inability to move properly. Low levels of dopamine are also linked to Parkinson's disease. Focus and memory are also within dopamine's sphere of influence, as are feelings of reward, enjoyment and motivation. KCI.org states that dopamine is released by the brain during naturally rewarding experiences; if the brain lacks dopamine or receptor sites are blocked, you cannot experience these feelings.
Compulsion
Compulsions are defined as repetitive, ritualized behaviors enacted to reduce anxiety caused by an obsession. According to the University of Maryland Medical Center, compulsive behavior can become "excessive, disruptive, and time-consuming, and may interfere with daily activities and relationships." Compulsions can also include addictions to chemical substances as well as addictive behavior, such as gambling. Although compulsive tendencies are typically a part of OCD diagnosis, they can be a separate behavior disorder.
Dopamine and Addictive Behaviors
Many illegal substances, such as methamphetamines or cocaine, will trigger release of dopamine, which leads to feelings of pleasure and euphoria. Addiction to these drugs happens quickly, as you will typically seek to experience these feelings again. According to a study published in "Bioessays" in September 2010, if you experiment with a drug, it is considered a voluntary behavior. However, continued use of the substance can impair nerve pathways and receptor sites in the brain that are involved in your free will. Over time, your use of the drug becomes an automatic compulsion.
Dopamine and Compulsion
Although medical science does not know the specific cause of OCD behavior, compulsions may be correlated with abnormal levels of dopamine. According to KCI.org, an excess of dopamine can lead to uncontrollable and subconscious movements and thoughts like repetitive tapping or hair-pulling, called trichotillomania. According to Mayoclinic.com, dopamine and serotonin imbalances may play a role in compulsive hair-pulling. Many medications prescribed for OCD type disorders involve blocking dopamine receptor sites, thereby reducing the amount of dopamine signaling in the brain. More research is currently being conducted to further elucidate the role of dopamine in compulsive behavior.
References
- The Mayo Clinic: Neurotransmitters and Compulsion: Dopamine
- University of Maryland Medical Center: Parkinson's Disease
- KCI.org: Dopamine
- University of Maryland Medical Center: OCD Behavior
- "Bioessays"; Addiction: decreased reward sensitivity and increased expectation sensitivity conspire to overwhelm the brain's control circuit; N.D. Volkow et al; September 2010
- The Mayo Clinic: Trichotillomania
