Dopamine Plays A Role In The Development Of Schizophrenia

Schizophrenia is a psychotic disorder characterized by distorted thinking, impaired emotional responses, poor interpersonal skills and a distortion of reality. It is the most common of psychotic disorders that, in most countries around the world, affects around 1 per cent of the population. In terms of explanations for the disorder, two central types of explanations arise – psychological explanations and biological explanations. Whereas psychological explanations tend to focus on cognitive, emotional and environmental factors that may cause the disorder, biological explanations tend to focus on genetic, biochemical and neuro-anatomical factors as the cause of the

Research by Johnstone in 1994, explained the biological approach of interventions, explanation and treating of schizophrenia patients (Hansell & Damour, 2005). In studies of Fisher in 2001, discoveries that the brain had more dopamine receptors know as B_2 receptors in a person suffering from schizophrenia, than a non-suffer (Hansell & Damour, 2005). Biological findings of schizophrenia suggest that a genetic factor was hereditary, but not conclusive because the element of environment does make a difference (Hansell & Damour, 2005).

Had primate models to determine how the change in dopamine levels was related to mental disorders.

The major support and refutation of the dopamine hypothesis has come from the examination of dopamine receptors in these regions of the brain. There are two main types of dopamine receptors, D1 and D2. However, within the category of D2 receptors, there are three subtypes, D2, D3, and D4. (5) Through PET scan analysis of dopamine usage in the brain and post-mordum molecular analysis of brain tissue, researcher were able to determine relative levels of dopamine receptors in patients with schizophrenia compared to non-schizophrenics. Overall analysis of dopamine

This paper defines schizophrenia from a biological and psychological perspective and also provides treatment to help combat symptoms of schizophrenia. This paper has three important contributions. First, by defining and expanding on schizophrenia from a biological perspective, I can identify the nature related predispositions. After expanding from a biological approach, secondly, I will analyze schizophrenia from a psychological aspect by determining if there is any environment or nurturing externals that can result to schizophrenia. Lastly, I will provide treatment details and also reveal early signs to schizophrenia. This paper is important because schizophrenia is an epic mental disease and it is crucially important to bring awareness to the public of how we can limit the illness. It is unclear whether schizophrenia have only a biological background or psychological background, but what was discovered is that both contribute to schizophrenia. Positive and negative treatment can be combatted undergoing pharmaceutical and psychotherapy,

Schizophrenic patients are thought to have higher dopamine levels in their brains (overactive dopamine system). Many antipsychotics are designed to block dopamine receptors, and bind them, helping patients to improve and experience less severe symptoms, further proving the dopamine hypothesis. It was also found that drugs that increase dopamine levels (amphetamines) have caused more psychotics symptoms. This could partially result in a few psychotic symptoms occurring in the illness (GROMISCH, 2013).

Furthermore Parkinson’s disease, which is associated with a depletion of dopamine display behaviours characteristic of schizophrenia when given too much L-DOPA, a dopamine stimulant (Gershon, Angrist, and Shopsin, 1977 as cited in Kalat, 1992). In addition if schizophrenics are given drugs such as L-DOPA their symptoms are heightened. (Kalat, 1992).

Schizophrenia is one of the disorders that have been debated over the years also it has a difficult past and it is a psychological disorder that is noticeable by numerous diminished thinking, behaviours and emotions. The individuals who suffer from schizophrenia they usually hear voices in their head, have unusual beliefs but not based on reality and have different thoughts that are based on hallucination and delusions also changing in behaviour. However, even this very day the cause of schizophrenia is still unknown. Yet the psychologist states that the cause of the disorder is the combination of genetic and environmental factors. Schizophrenia is one of the most serious mental health disorders and it is treated with combination of

Schizophrenia is a chronic neurological disease that results in a combination of positive, negative, and cognitive symptoms. Positive symptoms of Schizophrenia include hallucinations and delusions. Negative symptoms of Schizophrenia most commonly consist of avolition, anhedonia, and alogia. Cognitive symptoms affect the person’s cognition. Patients with the disorder have disorganized speech and behavior, deficits in learning and memory, as well as deficiencies in abstract thinking and problem solving. Positive symptoms of Schizophrenia are commonly attributed to the abnormally high levels of dopamine (Konradsson-Geuken, slide 25). While there is no current cure for Schizophrenia there are different treatments that prove to help certain aspects of the disorder.

The Dopamine Hypothesis theorizes that the symptoms portrayed in Schizophrenia is can be explained by abnormal function of dopamine in the brain. There have been three versions of the Dopamine Hypothesis. The first version of the hypothesis focuses on the dopamine receptors. Antipsychotic drugs that impact the metabolization and reabsorption of dopamine where found to be effective in treating the symptoms. It was theorized that if the symptoms of a Schizophrenic episode can be treated by the use of dopamine

(Kalat, 2012). Bleuler used the term as a means of representing a major psychotic illness

The mesolimbic dopamine system plays a critical role in psychostimulant-induced locomotor activity (Hall, Powers & Gulley, 2009). Dopamine (DA) is a monoamine that has been long associated with the brain’s reward systems, and more recently, its effects on animal behaviour have been investigated (Barron, Sovik & Cornish, 2010). While becoming the most broadly used illicit drug world wide, Methamphetamine (MA) is an addictive psychostimulant which causes the brain to release excessive amounts of the chemical neurotransmitter DA, controlling pleasure (Carati & Schenk, 2011). It has been used to suppress food intake and most commonly, increase mental alertness and physical endurance (Seiden, 2004). When linking MA to the brain, its primary action is to elevate the levels of extracellular monoamine neurotransmitters, including dopamine, by promoting their release from the nerve endings (Xie & Miller, 2009). Evidence has shown that these drug-induced neuropathological changes might underlie deficits in cognitive behaviours in chronic MA abusers. MA preferentially increases synaptic dopamine concentrations in the mesolimbic dopaminergic system and initiates stimulating behavior (Di Chiara & Imperato, 1988). These ideas are further strengthened by data from animal studies showing that MA neurotoxicity is associated with impairments in motor learning (Daberkow, Kesner & Keefe, 2005) in rodents.

In the figure above, the proposed mechanism of dopamine (DA) as a placebo mediator is illustrated. After a placebo has been provided to a patient, DA neurons in the ventral tegmental area (VTA) are activated, which leads to the release of DA in the ventral striatum (nucleus accumbens, NAcc) and in the prefrontal cortex (PFC). Consequently, the PFC activates disease-specific mechanisms, such as opioids for placebo analgesia, dopamine for motor improvement in patients suffering from Parkinson’s disease, and perhaps serotonin (5-HT), which relieves depressive symptoms.

Dopamine also can have an excitatory or inhibitory affect on neurons, depending on the postsynaptic receptor (Carlson, 2011, p. 102). Dopamine is created in the frontal lobes of the brain and is associated with our beta brain waves (Jordon, 2008, ¶14). Dopamine controls the electric voltage of the brain. Acting like a natural amphetamine, dopamine controls energy, excitement, and motivation (Jordon, 2008, ¶14). Dopamine plays an important role in many physical and psychological functions such as blood pressure, metabolism, digestion, voluntary movement,