Day-night variation in aggressive behavior among psychiatric inpatients

Area of Science:

• Forensic Psychiatry
• Circadian Rhythms
• Behavioral Science

Background:

• Human aggressive behaviors exhibit a 24-hour cyclical pattern.
• Understanding temporal variations in psychiatric inpatient aggression is crucial for safety and resource allocation.

Purpose of the Study:

• To investigate whether the frequency of violence among psychiatric inpatients and towards hospital staff varies significantly over a 24-hour period.
• To identify specific time-of-day patterns in aggressive incidents within a psychiatric setting.

Main Methods:

• Analysis of 334 assault episodes over 5 years involving 119 psychiatric inpatients.
• Categorization of event times by hour and 6-hour intervals.
• Statistical analysis using cosinor and chi-squared tests to assess temporal variations.

Main Results:

• A significant 24-hour variation in assault behaviors was detected.
• Aggression peaked in the early afternoon.
• This pattern was consistent across genders and for single versus repeated episodes.

Conclusions:

• Psychiatric inpatient violence demonstrates a discernible circadian rhythm with an afternoon peak.
• Factors such as ward activity, patient interaction, and endogenous rhythms likely influence this pattern.
• Further research is warranted to elucidate the precise causal mechanisms.