ABSTRACT
DIFFERENTIAL DIAGNOSIS Depression Depression is common with a prevalence of between 5 and 10%. It is estimated that two-thirds of adults will suffer from depression at some point in their life. Depression has a male preponderance of 2 : 1 and usually comes on in the late 20s. Risk factors for depression include previous depression, signifi cant past medical illnesses and other psychiatric illnesses. It is defi ned by the presence of at least two of the three core symptoms (low mood, anhedonia and fatigue) for at least two weeks. The severity of depressive illness is classifi ed as mild (total of 4 symptoms), moderate (5 or more symptoms) and severe (7 or more symptoms). The presence of psychotic symptoms such as hallucinations or delusions (mood congruent) indicates severe depressive illness.
