Effect of high climate temperature on the behavioral and psychological symptoms of dementia

Abstract

Objective: The objective of this study was to investigate if high climate temperature could have a negative effect on behavioral and psychological symptoms of dementia (BPSD).

Design: We conducted a retrospective study.

Setting and patients: Six patients discharged from the "Richiedei" Alzheimer Rehabilitation Unit-Italy during a period of very high climate temperature (June 14-21, 2002, 30.4 degrees C [86.7 degrees F]) are defined as the case-group. Sociodemographic, clinical, and therapeutic characteristics are compared with those of patients discharged during the previous 5 weeks (I control-group, n = 10) and the following 5 weeks (II control-group, n = 9).

Methods: On admission and on discharge, a multidimensional evaluation was performed assessing mental and functional status, BPSD (Neuropsychiatric Inventory, NPI), somatic health status, and pharmacotherapy. Changes in BPSD severity was computed as the difference in NPI total score (Delta-NPI) between the last and the first week of stay. Atmospheric temperature was also considered.

Results: The three groups did not differ with respect to sociodemographic, clinical, and therapeutic characteristics. On admission, frequency and severity of BPSD were similar among groups; whereas on discharge, the case-group had an increase in NPI scores (NPI during the first week [median], 13 in the case-group vs. 21 in the I control-group vs. 20.5 in the II one; during the last week: 24.5 vs. 9.5 vs. 15, respectively).

Conclusion: High climate temperature could have a negative impact on behavior in demented patients. To explain the possible mechanisms of the negative impact of high climate temperature on behavior, two hypotheses are proposed.