Paranoia: Prevalence and Correlates

Clinicians dealing with psychiatric disorders commonly encounter patients with paranoia in their clinical practices.  However, it is important for clinicians to understand the relatively frequency of paranoia endorsement by people in the general population.  Whether paranoia is a pathological phenomenon commonly depends on the degree of paranoia, associated signs and symptoms and presence (or absence) of a formal psychiatric diagnosis.  Freeman and colleagues from the Institute of Psychiatry other colleagues in London published an important paper to address this issue.

Their data and research stems from a general population study of over 7,000 general population survey respondent in England.  To assess paranoia in the general population, subjects were asked three questions where positive responses reflected increasing severity of paranoia.  The three questions in the survery (and the general population rate of endorsement) were:

• Paranoia level 1. ‘Over the past year, have there been times when you felt that people were against you?  (18.6%)
• Paranoia level 2. ‘In the past year, have there been times when you felt that people were deliberately acting to harm you or your interests ? (8.2%)
• Paranoia level 3. ‘In the past year, have there been times you felt that a group of people was plotting to cause you serious harm or injury?  (1.8%)

I found it interesting the relatively high rate of endorsement of paranoia level 1 in the general population.  Nearly one in five endorsed feeling times in the last year when they felt that people were against them.  As the severity of paranoia increased, the prevalence rates decreased to less than 2% of the population fealing a good of people was plotting to cause them harm or injury.

The research also looked at some of the correlates of paranoia.  Those endorsing each level of paranoia were compared to those with no endorsement of paranoia.  The paper is packed with data but here are some of the things that stood out for me:

• Level 1 paranoia was more likely to be endorsed by women while level 3 paranoia was more likely to be endorsed by men
• Paranoia rates were higher in populations with a variety of medical conditions including: diabetes, hearing or visual problems, recent heart attack/angina.  There was a trend for increased level 3 paranoia in those with obesity (BMI greater than 30 kg/m2)
• Paranoia rates were higher in a variety variables indicating social isolation, i.e. separated, divorced or single marital status, fewer number of close family members or friends, fewer supportive relationships
• Paranoia rates were higher along with a variety of other psychiatric symptoms/disorders, i.e. insomnia, depression,worry, anxiety, panic and PTSD
• Paranoia rates were increased in those endorsing suicidal thoughts in past year, history of a suicide attempt, anxiolytic and antidepressant drug use and not surprisingly antipsychotic medication use
• Paranoia rates were strongly and progressively associated with cannabis use and less strongly associated with heavy drinking

In summary, this research manuscript provides a valuable overview of paranoia.  Elements of paranoia are relatively common in the general population.  Paranoia is a marker for many other psychiatric syndromes and cannabis abuse.  Clinicians should include screening questions for paranoia in routine clinical assessment.

Photo of Japanese Maple Courtesy of Yates Photography

Freeman, D., McManus, S., Brugha, T., Meltzer, H., Jenkins, R., & Bebbington, P. (2010). Concomitants of paranoia in the general population Psychological Medicine, 41 (05), 923-936 DOI: 10.1017/S0033291710001546