The first thing to keep in mind is the depressed person cannot help feeling depressed. This behaviour will disappear with treatment. You can help by distracting the depressed person by keeping them busy with tasks they can accomplish easily. Short conversations are better than long talks. As the person recovers, encourage them to be more active and resume their previous responsibilities.
Suicide can be a worry.
Asking about thoughts of suicide is not going to encourage a suicide attempt. Talking about suicidal thoughts is often a great relief to the depressed person. However, anyone seriously thinking about taking their life is in need of urgent professional help to prevent a tragedy. Families should inform the doctor of any concerns they have. The New Mood Therapy - D. Burns, Signet, New York, 1980.