Can you please tell me how schizophrenia and severe depression with psychotic features differ?

Timeline Difference: Schizophrenia is disturbance in thought (2 or more of the following: delusions, disorganized behavior or speech, hallucinations, flat affect) that has persisted over 6 months. Major depressive disorder with psychotic features includes signs of depression present for at least 2 weeks, along with episode(s) (that often resolve in a short time period) of psychosis.

Underlying nature: Schizophrenia is chronic condition with impaired capacity to tell between reality /fantasy (delusions/hallucinations). It's recurrent, tends to progressive deterioration of baseline function. Depression can be so severe to cause break in reality testing - for example, beliefs world is ending, delusional worthlessness, etc. It is not usually recurrent and appropriately treated, resolves fully.

Main differences: In major depression: psychosis gets resolved as you treat depression. In contrast, you will see psychotic symptoms regarldless of mood symptoms in schizophrenia spectrum problems.

Schizo vs depression: Depression with psychosis have above all, all t he symptoms of depression + psychotic features in which the auditive hallucination can be [usually] much milder and duration of each hearing much shorter, less clearly heard, much less affecting the sick person [other sx are also as mild in visual or paranoia-delusions]. Schizo sx. Are long lasting, can be all day, severely affecting the person.

Psychosis is a : Symptom that can happen in a number of illnesses including infections and sleep depravation. And yes, it can occur in serious depressions as well. The difference is that once the depression resolves, functioning is fully restored while schizophrenia is a chronic, relapsing illness.