A condition which causes serious disorder in a person’s behaviour or thinking.
More example sentences
- There are a huge number of people who have serious mental illnesses who don't always have the illness in an acute manner.
- Bipolar affective disorder is a common condition which, among mental illnesses, ranks second only to unipolar depression as a cause of worldwide disability.
- There are many different kinds of neuro-psychiatric disorders or mental illnesses where hallucination plays a role.