Mental health encompasses our emotional, psychological, and social well-being. It influences how we think, feel, and act. It also determines how we cope with stress, how we relate to others, and how we make healthy choices.
There are basically four types of mental health and they are mood disorders (such as depression or bipolar disorder) and anxiety disorders. personality disorders. psychotic disorders (such as schizophrenia)

As you said that your husband is suffering from depression, it may be:

-appear sadder or more tearful than usual be
-more pessimistic than usual or hopeless about the future
– talk more often than usual about feelings of guilt, emptiness or worthlessness have less interest in spending time together or communicate less often than usual get upset easily or appear unusually irritable have less energy than usual move slowly.

Here are some points on how you can help him:

-You can try to communicate with him.

-You can try to support him.

-You can appoint him a therapist.

-You can try to be there while continuing his therapy.