Classification of schizophrenia. Schizophrenia is classified as a severe mental disorder characterised by a range of symptoms. Positive symptoms include hallucinations, such as hearing voices, and delusions, which are false, fixed beliefs. Negative symptoms include speech poverty, where communication becomes limited, and avolition, marked by a lack of motivation or goal-directed behaviour

Schizophrenia is linked to dopamine imbalances, with overactivity in the mesolimbic system contributing to positive symptoms and underactivity in the mesocortical pathway linked to negative symptoms. The reformulated dopamine hypothesis highlights broader neural dysfunction, including glutamate dysregulation, where reduced glutamate activity may explain cognitive and emotional symptoms. These insights point to a complex interplay of neurotransmitters in schizophrenia.