The Role of Serotonin in Impulsive and Aggressive Behaviors

Human brain is considered as the highly evolved organ to execute diverse environmentally adapted functions which may rely on the interaction between the cognitive and visual skills. Disorders associated with the mental function may lead to abnormal psychological behavior.

I am having keen interest in understanding the psychopathology of certain disorders connected with abnormal psychology like cognitive problems, bipolar disorder, and depression. This is because these problems are directly concerned with the abnormal thoughts and behavior that might affect the functions of interpretation, prediction, and explaination that they are essential to perform daily tasks in the society.

Further, performing these roles would require the strength of internal mental processes such as problem solving, memory, and language. There are various concepts and theories put forward in connection with the abnormal psychology and it is essential to highlight some of the elements of the relevant theories.

Gestalt theorists were first to focus on perceptual organization of neurocognitive skills and proposed the theory of visual perception. It deserves interest because it is concerned with the perception of things as an organized whole rather than distinguishing them as separate parts. Individuals having poor cognition levels may perceive the things but might fail to interpret and describe them. This is because their perception levels may be more adapted to remember the whole information rather than retaining the information as distinct parts.

This may not be the case with the intellectually superior individuals who could remember the information of the objects both as different units and as organized whole.

Therefore, Gestalt theory may provide better insights in understanding the levels of perceptual organization in individuals especially with psychological abnormalities. Next, the other element worth interesting to be used is the connection between abnormal psychology and bipolar disorders.

Bipolar disorder constitutes a kind of mental illness characterized by maniac symptoms that alter the mood. Its main categories are Biploar I, Bipolar II and Bipolar NOS (Not otherwise specifed). Bipolar disorders were diagnosed using the criteria of American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM). The version that is presently in clinical practice is that of DSM-IV-TR.

Bipolar disorders contribute to cognitive impairments. It was reported that different states of bipolar illnesses determine the relationships among clinical features, neuropsychological performance, and psychosocial functioning. (Martínez-Arán et al, 2004). Their experiments have revealed cognitive dysfunction in verbal memory and frontal executive tasks that are essential for the daily life (Martínez-Arán et al, 2004).This was further strengthened by another report that described that disturbances in attention, visual memory, and executive function are mostly involved in the pathogenesis of bipolar disorders (Roger et al., 2006).

Since attention problems are evident in the episode of bipolar disorders, it is reasonable to connect this description with the psycholopathology of Attention deficit hyperactivity disorder (ADHD) which is also diagnosed as per the criteria of DSM IV. This disorder is mostly prevalent in children between the age of 5 and12 and affects their mental functions (Mukhopadhyay et al., 2003).

Bernfort, Nordfeldt, and Persson (2008) highlighted in a study that ADHD children’s ability in environment is likely to enhance the risk that would persist till the stage of adulthood.

They have further highlighted problems that lead to poor educational outcome, psychosocial problems, substance abuse, psychiatric problems and risky behavior. Therefore, it may appear that these disorders are presenting behavioral problems which may be worth noting. Hence it is reasonable to connect this part of description with the theory of behaviorism mostly influenced by Ivan Pavlov.

This is because the philosophy of behavior psychology mostly centers its focus on acting, thinking and feeling that may be susceptible to impairment by psychopathological conditions, Hence, it appears very interesting in the present context. Next, the successful performance of various psychological tasks may rely on special chemicals that serve as agents in transporting the information between a neuron and a cell. These agents are better known as neurotransmitters. Some of the well known neurotransmitters are acetylcholine, dopamine, and serotonin. The present description deals with serotonin.As a neurotransmitter, serotonin is involved in the modulation of anger, aggression, mood, and sleep. Since these functions are linked to the central nervous system (CNS), it is reasonable to infer that serotonin could influence the psychopathology. So, there is a need to review the literature in this context. Serotonin is having association with depression. It was reported that central serotonin (5-HT) dysregulation contributes to the susceptibility for mental disorders, including depression, anxiety, and posttraumatic stress disorder, and learning and memory deficits (Dai et al., 2008). Serotonin also contributes to schizophrenia through the episodes of depression. Iqbal and Van Praag (1995) described that the interruption of certain serotonergic circuits could represent an antipsychotic principle.

They further suggested that the involvement of serotonergic dysfunctions in the pathogenesis of schizophrenic psychoses. This was further supported by another report that described that serotonergic system as the underlying cause of depression which could strengthen the link between defective neurotransmitter function and the symptoms of depression (Leonard, 2007).A recent report has provided further insights that older patients with schizophrenia are presented with both depressive and psychotic features that could be evaluated by selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine, sertraline, fluvoxamine and citalopram (Kasckow & Zisook, 2008).Since depression and schizophrenia alter the attention and mood of a particular individual, it is reasonable to infer that serotonin may influence the neuro-cognitive area of psychopathology. Mühlbauer (1985) previously reported that aggression was linked to serotonin indicating that the biochemical aspects of aggression are regarded as a dysbalance syndrome causing well-defined vulnerability which, in turn would become the basis of the psychopathology of its phenomena. Keele (2005) further supported that serotonin contributes to the neuronal hyperexcitability that leads to impulsive and aggressive behaviors. These are associated with complex partial seizures (CPS) which may be comorbid with emotional disturbances, especially major mood disorders. Since mood alterations are characteristic of Bipolar disorders, it is reasonable to infer that serotonin could play vital role in the pathogenesis of bipolar spectrum of disorders. Weltzin, Fernstrom and Kaye (1994) reported that serotonin (5HT) could be one of the neuromodulators of feeding.

They have experimentally reduced 5HT activity in animals and found increase in food intake. While, increasing 5HT activity was found to reverse the effect. Their findings have suggested that women with bulimia nervosa show signs of reduced 5HT activity, which may be related to binge eating. Therefore, they described that the data supporting the theory that reduced CNS 5HT activity may play a role in the pathophysiology of bulimia nervosa. They have also highlighted that the abnormalities of 5HT activity and its association to other psychopathology of other disorders such as depression, substance abuse, and impulsivity. This may indicate that the abnormal perceptual feelings of the brain towards food might have predisposed the individual to develop a state of altered psychological behavior. Hence, these results have clearly indicated that serotonin is strongly linked to the neurotransmission. Therefore, it is reasonable to infer that serotonin played important role in influencing the neurocogniton and its psychopathology through its effects on mood disorders.depression, schizophrenia aggression, and bulmia nervosa.


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