Abstract
Objective: Clinical studies suggest resting thermoregulatory cutaneous vasomotor tone could be increased in schizophrenia, resulting in reduced hand blood flow. In animal models, atypical antipsychotics including clozapine potently inhibit sympathetic neural outflow to the thermoregulatory cutaneous vascular beds. We have now determined whether antipsychotic medication administration is associated with an acute increase in hand blood flow in patients with schizophrenia and schizoaffective disorder, and whether this increase correlates with clinical status.
Method: Hand temperature was measured with an infrared camera in 12 patients with chronic schizophrenia or schizoaffective disorder 30 min prior to, then 30 and 60 min following medication. Clinical status was assessed via the Brief Psychiatric Rating Scale (BPRS). Results were compared using regression and repeated measures analysis of variance.
Results: A robust and significant increase in hand temperature (p < 0.001) was observed following antipsychotic administration. The mean increase after 60 min was 4.1 ± 2.4°C. This increase was significantly associated with colder hand temperature prior to medication (p < 0.05; suggestive of increased resting vasoconstriction) and with more severe psychiatric symptoms (p < 0.05).
Conclusions: Atypical antipsychotics were associated with increased hand blood flow, consistent with inhibition of thermoregulatory sympathetic outflow to the cutaneous vascular bed in patients with schizophrenia and schizoaffective disorder. This increase correlated with symptom severity. Hand temperature increase following antipsychotic medication may therefore be a simple and informative physiological marker of disease activity and potential response in patients with schizophreniform disorders. Given that antipsychotics also inhibit sympathetic outflow to brown adipose tissue, which normally converts energy to heat, future studies should examine whether antipsychotic-induced hand temperature increase is associated with antipsychotic-induced weight gain.
Declaration of interest: Reza Arpandy undertook this work as part of his Advanced Medical Science thesis completed in 2008. William Blessing was supported by NHMRC Senior Principal Research Fellowship (480408). Christos Pantelis was supported by a NHMRC Senior Principal Research Fellowship (ID: 628386) and NHMRC Program Grants (ID: 566529). In the last five years, Christos Pantelis has received grant support from Janssen-Cilag, Eli Lilly, Hospira (Mayne), Astra Zeneca. He has provided consultancy to Janssen-Cilag, Eli Lilly, Hospira (Mayne), Astra Zeneca, Pfizer, Schering Plough, Lundbeck. The study was supported by the clinical team at the Adult Mental Health Rehabilitation Unit (AMHRU), Sunshine Hospital, St. Albans, Australia. The equipment to assess hand temperature was supported by a grant to William Blessing from Flinders Medical Centre Research Foundation.