Final answer:
Behavioural activation is a therapeutic approach that aims to modify depression-maintaining behaviors by increasing positive activities and reducing engagement with negative behaviors, as a treatment for depression.
Step-by-step explanation:
The behavioural theory of depression, referred to as behavioural activation, is a therapeutic approach that identifies and helps individuals to change potentially depression-maintaining behaviors. Behavioural activation treatment for depression is designed to increase the patient's contact with positively reinforcing activities, to reduce their engagement with behaviors that maintain depression, and to improve overall functioning.