The Brain Electrical Physiological Study On Craving Of Amphetamine Type Stimulants Dependent Individuals

Aims: 1. To develop an Amphetamine-Type Stimulants Addiction Stroop task to assess attentional bias with ATS addicts. 2. During different periods after acute detoxification, using neural electrophysiology research techniques to evaluate attentional bias pattens to ATS related word cues and trends of event related potentials illicited using ATS Addiction Stroop Task. 3. To exam relationships between subjective craving and event related potentials illicited using ATS Addiction Stroop Task, help to explore objective indicators to subjective craving among ATS addicts.Methods: 1. Thirty ATS dependent patients were recruited in study. Qualitative research methods were carried out to screen ATS related words. Neutral control words were matched by physical attributes and emotional attributes for developing the ATS Addiction Stroop Task. 2. 26 ATS dependent patients were compared with 29 normal controls.To evaluate pattens of attention bias to ATS related cues and trends of event related potentials elicited using ATS Addiction Stroop Task at baseline, month 3 and month 6 after acute detoxification. 3. The ATS Addiction Stroop Task was presented to 26 ATS dependent patients at baseline, month 3 and month 6 after acute detoxification. Before the experiment started, subjective craving was assessed by using Visual Analogue Score(VAS). Regression analysis was conducted to explore relationships between subjective craving and event related potentials illicited using ATS Addiction Stroop Task.Result:1. ‘Ice’ and ‘Skating’ were selected as ATS-related stimulus words, when ‘weed’ and ‘solve’ were selected as neutral control word. The results showed that ATS-related stimulus words’ strokes, word length(2 vs 2), valence(F = 2.101, p> 0.05), arousal(F = 2.101, p> 0.05), familiarity(F = 2.101, p> 0.05) were not significant different from that for neutral control word. 2. Results from baseline showed:(1) behavioral performance:The reaction time between ATS dependent patients and health controls showed no significant difference(Fword*group interaction=0.967,p=0.382), and error rate between two groups showed no significant difference(Fword*group interaction=2.645,p=0.136);(2) ERPs results: In order to explore the topographical P300 differences between patients and controls, the recording sites were integrated into 6 regions of interest(ROIs) including left-anterior, Left-posterior, Medial-anterior, Medial-posterior, Right-anterior, Right-posterior. N2 amplitude(F word*region*group interaction effect=32.756, p= 0.005), N2 latency(F word*region*group interaction effect=35.805, p=0.002), P2 amplitude(F word*region*group interaction effect= 69.508, p<0.001) showed significant group difference between ATS dependent patients and health controls. Post hoc multiple comparisons according to different ROIs suggested a smaller N2 amplitude(F word*group interaction effect=6.166, p=0.013) over right-anterior ROIs, a shorter P2 latency(Fword*group interaction effect=6.515, p=0.011) over right-anterior ROIs and a higher P3 amplitude(Fword*group interaction effect=7.307, p=0.007) over left-anterior ROIs for ATS addicts than that for health controls. 3. Results from evaluation at baseline, month 3 and month 6 after acute detoxification:(1) behavioral performance:ATS dependent patients and health controls showed no reaction time difference(Fword*time*group interaction=5.063, p=0.408) and no error rate difference(Fword*time*group interaction=23.324, p=0.052);(2) ERPs results: all components of ERPs showed significant difference between ATS addicts and health controls. Post hoc multiple comparisons according to different ROIs showed N1 amplitude over left-anterior ROIs(Fword*time*group interaction =25.208, p=0.001), N2 amplitude over medial-anterior(Fword*time*group interaction =16.604, p=0.020), N2 amplitude over right-anterior(Fword*time*group interaction =18.351, Results:p=0.010), N2 latency over medial-posterior(Fword*time*group interaction =19.929, p=0.006), P2 amplitude over left-posterior(Fword*time*group interaction =15.033, p=0.036), P2 latency over left-posterior(Fword*time*group interaction=16.965, p=0.018), P3 amplitude over left-anterior(Fword*time*group interaction=28.986, p<0.001), P3 amplitude over right-anterior(Fword*time*group interaction=15.418, p=0.031), P3 latency over right-posterior(Fword*time*group interaction=19.943, p=0.006) have significant group difference. According to results for ATS addicts above, ATS words related N2 amplitude over medial-anterior gradually increased(baseline vs 3-month end: p=0.003; baseline vs 6-month end: p<0.001; 3-month end vs 6-month end:p=0.045), ATS words related P2 amplitude over left-posterior increased(baseline vs 3-month end: p<0.001; baseline vs 6-month end: p=0.015; 3-month end vs 6-month end: p=0.254), ATS words related P2 latency over left-posterior extended(baseline vs 3-month end: p=0.072; baseline vs 6-month end: p=0.233;3-month end vs 6-month end: p=0.003). ATS words related P3 amplitude over left-anterior decreased(baseline vs 3-month end:p=0.003; baseline vs 6-month end: p=0.004;3-month end vs 6-month end: p=0.973). 4. ATS addicts’ craving assessed by VAS decreased during 3-month afer acute detoxification(4.2 ± 3.1 vs 2.4 ± 3.0, t=4.089, p<0.001), but no significant changes were observed from 3-month to 6-month(2.4 ± 3.0 vs 2.5±2.6, t=-0.094,p=0.926).Linear regression coefficients were calculated between craving levels before the experiment and mean value of ERP components illicited by ATS related word. Significant correlations were found between the N1 amplitude over left-anterior(B=-0.211、p=0.017),N2 amplitude over medial-anterior(B=0.199、p=0.005), N2 amplitude over right-anterior(B=0.153、p=0.023) and the self-report craving score.Furthermore,during first 3 monthes after acute detoxification, change values of N1 amplitude over left-anterior(B=0.213, p<0.001), N2 amplitude over right-anterior(B=0.213, p<0.001),P3 amplitude over left-anterior(B=0.213, p<0.001), were significantly correlated with change values of self-report craving score.Conclusions:1. This study provides neurophysiologic evidence elicited using ATS Addiction Stroop Task that attention bias to drug-related words is abnormal in ATS dependent patients. With the extension of the withdrawal period, attention bias reduced continuously during first 6 months after acute detoxification. 2. A positive correlation was found between P3 average amplitude value at left-anterior of head and the ATS dependent patients’ subjective craving, which provide neurophysiological evidence for exploring a potential objective indicator to ATS addicts’ craving.