Autonomic functions and audiovisual reaction time in heroin addicts

Radial pulse rate, systolic BP (SBP), diastolic BP (DBP), initial GSR0), GSR after 5 minutes of relaxation (GSR5), auditory reaction time (ART) and visual reaction time, (VRT) were measured in 30 male heroin addicts and compared with 25 male control subjects of similar age group. In heroin addicts DBP was significantly low (71.73 mmHg +/- 7.42, P < 0.05); while SBP although being low (106.13 mmHG +/- 10.08) was not significant. However, radial pulse was significantly higher. GSR0 was significantly higher (P < 0.001) but GSR5 was not significantly higher in these addicts, suggesting less sympathetic activity. In a separate group of ten heroin addicts effect of change in posture from supine to erect on BP was studied. This did not produce any rise in SBP or DBP at 1 and 2 min, suggesting probably inhibition of baroreceptor reflex. Auditory reaction time (ART) and visual reaction time (VRT) were significantly prolonged (P < 0.001 for each) in addicts, indicating deterioration of processing capability of CNS, or poor sensory-motor performance, or both.