Suggests that abnormality is has a biological basis.
This approach has a number of key features:
- Infection- Suggests that mental illness can be caused when bacteria and infections invade the body.Eg; general paresis, occurs when bacteria invades the nervous system and damages the brain.
- Biochemistry-Having too much or too little of important chemicals in the brain lead to mental illness. For example depression is linked to too little serotonin.
- Brain Damage- Some psychological disorders occur as a direct result of brain damage. Case of Phineas Gage had a metal rod passed through his head which made him become anti social.
- Genetics- Suggested that we can inherit mental illness. For example Holland et al's study of eating disorders showed when one twin had an eating disorder there were high chances of the other identical twin developing one.