Biological Model & Psychopathology

1. Biological Model & Psychopathology
By: Urwah Ali

2. Biological Approach
• Took medical perspective
• Disorders have an organic or physical cause
• The focus of this approach is on genetics, neurotransmitters,
neurophysiology, neuroanatomy etc
• The approach argues that mental disorders are related to the
physical structure & functioning of the brain

3. BIG-B Model (Brain-damage, Infection, Genetics, Biochemistry)

4. Brain Damage
• Abnormal behavior can occur if the structure of the brain is
damaged in some way
• An example is that of enlarged ventricles (Ventricles are sacks
of fluid in our brain)
• People with schizophrenia tend to have larger ventricles than
the normal population
• Another example is Alzheimer’s disease, a type of dementia
caused by the loss of cells in the nervous system

6. Infection
• The flu virus has been linked to schizophrenia
SCHIZOPHRENIA & PRENATAL VIRAL EXPOSURE
• Women appear to have contracted the flu virus during the first
trimester of pregnancy led to poor neural development &
schizophrenia
• Syphilis is a STD that has been known to cause brain damage
& therefore can be shown to lead to abnormality

7. Genes
What does it mean if a mental disorder seems to run in
family?
• The chance of an individual having a specific mental disorder is
higher if other family members have that same mental disorder
• Even though a mental disorder may run in a family, there may be
considerable differences in the severity of symptoms among family
members. This means that one person in the family may have a
mild case, while someone else has a more severe case of the
mental disorder

8. Causes of Mental Disorders
• Most mental disorders are caused by a combination of
multiple genetic & environmental factors. This is
called multifactorial inheritance.
• Many common medical problems such as Type 2 diabetes,
obesity & asthma also undergo multifactorial inheritance
• Anxiety disorders, PTSD, OCD & major depressive disorder
are about 20-45% inherited
• Alcohol dependence & anorexia nervosa are 50-60%
inherited, whereas
• Bipolar disorder, Autism Spectrum Disorder (ASD),
Schizophrenia & ADHD are upwards of 75% inherited

9. Environmental factors
Environmental factors contributing to the development of mental
disorders include:
• Trauma: Sexual, physical & emotional abuse during childhood all
lead to an increase in the likelihood of developing a mental disorder.
Highly stressful home environments; loss of a loved one & natural
disasters are also major contributors
• Emotional Harm: Negative school experiences & bullying can also
result in severe long-term emotional damage
• Substance Abuse: Exposure tobacco, alcohol & illicit drugs either
prenatally or in childhood has been associated with the development
of mental disorders beyond just substance use disorders or
addiction

10. Genetic Factors
Environmental factors alone do not cause mental disorders. Genetic
factors also play a part in developing a mental disorder.
• Humans have 23 pair of chromosomes (each with numerous
genes that control the characteristics & trait a person inherits)
• Seems no single gene is involved for particular behavior
or disorder
– Down's Syndrome or Trisomy 21
– Edward's Syndrome or Trisomy 18
– Patau Syndrome or Trisomy 13

11. Behavior Genetics
• The study of how individual
differences in genetic
makeup contribute to
differences in behavior
• Genotype - e.g., inherited
blue eye color
• Phenotype – e,g., height,
weight & skin color
• The phenotype can change
over time as a function of
the interaction of genes &
environment

12. METHODS OF BEHAVIORAL GENETICS
 Family studies
 Twin studies
 Adoption studies
 Molecular Genetic studies

13. Separated at Birth
https://allthatsinteresting.com/jim-twins
https://www.nationalgeographic.com/ma
gazine/2012/01/identical-twins-science-
dna-portraits/
https://www.ripleys.com/weird-
news/jim-twins/

14. Thankyou