How come i have schizoaffective disorder, but nobody else in the family has it?

Not Unusual: Problems such as schizoaffective disorder tend to occur more often in families, but this is not always the case. It is likely that you have close family members with depression or bipolar disorder, because problems with mood tend to be associated with schozoaffective disorder.

Multifactoral: Some researchers now believe that certain psychotic disorders are a result of a genetic mutation, which can occur in individuals where there is no family history of such a condition. Heredity plays a role in some or even most, but not all.