Epidemiology
In researching over 1000 individuals of vast backgrounds, Stompe and colleagues (2006) found that grandiosity remains as the second most common delusion after persecutory delusions. A variation in the occurrence of grandiosity delusions in schizophrenic patients across cultures has also been observed. In research done by Appelbaum et al. it has been found that GDs appeared more commonly in patients with bipolar disorder (59%) than in patients with schizophrenia (49%), followed by presence in substance misuse disorder patients (30%) and depressed patients (21%).
A relationship has been claimed between the age of onset of bipolar disorder and the occurrence of GDs. According to Carlson et al. (2000), grandiose delusions appeared in 74% of the patients who were 21 or lower at the time of the onset, while they occurred only in 40% of individuals 30 years or older at the time of the onset.
Read more about this topic: Grandiose Delusions