A 68 years old lady thinks that she has done a sin, she is not worth to live this world, she is also having anorexia and insomnia, she is suffering from -
Diagnostic criteria for Major depression 

Five or more of the following symptoms for at least 2 weeks.


Depressed mood
Loss of interest or pleasure in all      
Decreased or increased appetite
Insomnia or hypersomnia
Psychomotor retardation or agitation
Fatigue or loss of energy
Feeling of worthlessness or excessive guilt
Diminished concentration
Suicidal thoughts or attempts

Diagnosis of Minor depression

If less than five but more than two (i.e. 2-4) of the above symptoms are present for at least 2 weeks then the diagnosis is minor depression.

Coming to question

This patient has:-

i) Excessive guilt (she has done a sin)
ii) Suicidal thoughts (not worth to live this world)
                iii) Anorexia (decreased appetite)
                iv) Insomnia


So, this patient has less than 5 symptoms but more than 2 symptoms but more than 2 symptoms Diagnosis is minor depression.
Now the question arises, which type of depression is it?


Endogenous depression :- No external precipitating event or stressors.
Reactive (neurotic/exogenous) :- Precipitated by external events or stressors, e.g. loss of a loved one, failure in love etc.


As no external precipitating factor has been mentioned in the question, this patient is having endogenous depression.
So, the final diagnosis is endogenous minor depression. (If the symptoms would have been 5 or more --> endogenous major depression).
Exogenous depression
Endogenous depression
Neurotic depression
Dissociate disorder