The Possible Biological Causes of Mental Illness

 Running head: CASE STUDY 1
Case Study
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CASE STUDY
1. The Possible Biological Causes of Mental Illness
A. Mental illness may be caused by abnormalities in the structure and function of neural
circuits.
1) Reduction in the capacity to maintain activated neural circuits that would
result in a positive emotion (Heller, Johnstone, Shackman, Light, Peterson,
Kolden, Kalin, and Davidson, 2009)
2) Significant decrease in the number of neurons that expressed receptors for the
proper glutamergic neurotransmission, resulting in the development of
schizophrenia (Bitanihirwe, Lim, Kelly, Kaneko, and Woo, 2009).
3) Electroencephalography showed that the auditory response of the auditory
cortex is reduced among patients positively diagnosed with schizophrenia,
resulting in the occurrence of hallucinations (Spencer, Niznikiewicz, Shenton,
and McCarley, 2009).
4) Neural circuitry in the frontostriatal region of the brain is impaired among
patients with bulimia nervosa (Marsh, Steinglass, Graziano, O’Leary, Wang,
Murphy, Walsh, and Peterson, 2009).
B. Mental Illness may be Caused by Defective Brain Development
1) Certain regions of the brain, such as the lower occipital complex, fail to be
activated in patients positively diagnosed with a mental illness (Green, Lee,
Cohen, Engel, Korb, Nuechterlein, and Glahn, 2009).
2) Lesions in the prefrontal-subcortical regions of the brain result in the
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development of obsessive-compulsive disorder (Salinas, Dávila, Berthier,
Green, and Lara, 2009).
3) Larger cerebellar volumes were observed among teenage marijuana users
(Medina, Nagel, and Tapert, 2010).
4) Larger amydala volumes were observed among children who suffered from
poor emotional regulation (Tottenham, Hare, Quinn, McCarry, Nurse,
Gilhooly, Millner, Galvan, Davidson, Eigsti, Thomas, Freed, Booma, Gunnar,
Altemus, Aronson, and Casey, 2010).
C. Genetic Mutations may Result in the Development of Mental Illness
1) Mutations in the dopamine D2 receptor gene are associated with alcohol
dependence (Prasad, Ambekar, Vaswani, 2010).
2) The presence of a third sex chromosome of either X or Y is considered as a
common feature among Klinefelter children who are neurocognitively
impaired (Ross, Zeger, Kushner, Zinn, Roeltgen, 2009).
3) Mutations in the TRAPPC9 gene are related to the development of intellectual
disability (Mochida, Mahajnah, Hill, Basel-Vanagaite, Gleason, Hill, Bodell,
Crosier, Straussberg, and Walsh, 2009).
4) Mutations in the 7q36.1 chromosomal region are associated with
schizophrenia (Atalar, Acuner, Cine, Oncu, Yesilbursa, Ozbek, and Turkcan,
2010).
D. Abnormal Levels of Specific Proteins may Cause Mental Illness
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1) The excessive deposition of amyloid beta proteins in the brain cause
Alzheimer’s disease (Murphy and LeVine, 2010).
2) Low levels of the selenoprotein P results in the development of Alzheimer’s
disease (Takemoto, Berry, and Bellinger, 2010).
3) Excessive production of apolipoprotein E results in the development of
Alzheimer’s disease (Vemuri, Wiste, Weigand, Knopman, Shaw,
Trojanowski, Aisen, Weiner, Petersen, and Jack, 2010).
4) Reduction in the production of the protein glutamic acid decarboxylase-67
kDa is associated with the development of depression (Karolewicz, Maciag,
O'Dwyer, Stockmeier, Feyissa, and Rajkowska, 2010).
2. The Function of the Neurotransmitters in Depression
A. Neurotransmitters relay messages that are generated from the brain of an individual.
B. Neurotransmitters serve as chemical impulses that transmit messages between one
neuron to another.
C. Neurotransmitters serve as the connecting matter between two neurons that are in
synapse.
D. Three primary neurotransmitters are associated with depression, namely serotonin,
norepinephrine and dopamine.
E. The neurotransmitter serotonin regulates the emotions of an individual.
F. The neurotransmitter norepinephrine is responsible for the reaction of an individual to
stressful situations.
G. The neurotransmitter dopamine influences the sleep and the appetite of an individual.
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(Marsh et al., 2009; Savitz, Lucki, and Drevets, 2009).
3.1 The Cause of Margaret’s Mania
A. Margaret’s mania is mainly due to the excessive amounts of fluoxetine hydrochloride in
her body, due to her self-medication of doubling the dosage of the drug.
B. It is highly likely that Margaret is also suffering from bipolar disorder, also known as
manic-depressive syndrome, which has been undiagnosed by her attending physician.
C. Margaret’s mania may also be due to the imbalance in the levels of dopamine in her
body, resulting in her lack of sleep and her hyperactivity. The excessive amount of
dopamine may overstimulate the dopamine receptors of the brain, resulting in a
disconnection in the neural circuitry of the prefrontal cortex of the brain (Hairns and
Arnsten, 2008)
3.2 Other possible causes of mania
A. Mania may also be due t