Introduction
Addiction is a neurological disorder that impairs reward system in the brain (Peter and Charles, 2007). Methamphetamine is the second most illicitly abused drug after Cannabis in Australia (McKetin et al., 2009). It is one of the most powerful and addictive stimulant that causes brain dysfunctions. Methamphetamine increases release of neurotransmitter dopamine that is involved in reward and generation of pleasurable emotions (Volkow, 2001). Repeated use of methamphetamine causes excessive release of dopamine and results in the loss of behavioural control (Volkow et al., 2007). This report will first introduce physiology of reward and pleasure and role of neurotransmitter …show more content…
All addictive drugs including methamphetamine activate the dopamine cells in ventral tegmental area (Peter and Charles, 2007). Addiction can be described as uncontrollable and persistent reward seeking behaviour regardless of the adverse consequences that may ensue (Shippenberg et al., 2007). It is a pathological change in the neurological functions caused by repeated abuse to the brain which regulate person’s behaviour (Peter and Charles, 2007). Methamphetamine excites dopamine producing neurons causing more action potential generation in the absence of experience of …show more content…
Neurons do not readily react to the same amount of dopamine after repeated over-stimulation of neurotransmitter (Cho and Melega, 2001). It also undergoes adaptive change as neurons weakly response to dopamine. Repeated methamphetamine use also causes reduction in dopamine transporter availability. According to the study conducted Volkow et al. (2007), it is found that dopamine transporter availability is significantly lower in methamphetamine abuser. Decrease in dopamine transporters result in reduced ability to re-uptake dopamine. Methamphetamine abusers thus are likely to increase amount of dose to experience same rewarding effect and this makes them addictive and dependent to