Biological Approach

Biology is defined as the study of life (from the Greek bios meaning ‘life’ and logos meaning ‘study’). A biological perspective is relevant to the study of Psychology in three ways:

1. Comparative method: different species of animal can be studied and compared. This can help in the search to understand human behaviour.
2. Physiology: how the nervous system and hormones work, how the brain functions, how changes in structure and/or function can affect behaviour. For example, we could ask how prescribed drugs to treat depression affect behaviour through their interaction with the nervous system.

3. Investigation of inheritance: what an animal inherits from its parents, mechanisms of inheritance (genetics). For example, we might want to know whether high intelligence is inherited from one generation to the next.

How do drugs have a psychological effect?

Many neurological disorders are caused by the imbalance of neurotransmitters such as dopamine and serotonin in the brain. For example, the "dopamine hypothesis" suggests that schizophrenia is linked to abnormal levels of dopamine in the brain. Drugs such as anti-depression narcotics affect a user's mood by using chemicals to change the movement of transmitters like serotonin between cells. 

What happens to the transmitter

Once the transmitter has served its purpose, it will either be broken down by enzymes or be transferred back to the nerve ending and reused this second option is called re-uptake.