How can major depression affect my interests in life?

Lower motivation. Symptoms of major depression often include sadness, withdrawal, difficulty concentrating, appetite/weight changes, fatigue, low energy, hopelessness, guilt feelings, and sleep difficulty. Depression can also distort the way events are perceived, resulting in negative self-perceptions and loss of interest in previously enjoyed activities.
Yes. One of the more common symptoms of depression is a loss of interest in usual activities. Often it is associated with a lack of satisfaction or pleasure from activities. These symptoms are temporary. They go away with recovery from depression.
Depression. Anhedonia, anergia and lack of motivation or interests, depending on how severe the depression is.