Subjects: Psychology >> Developmental Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》
Abstract： The person-centered methods, including latent class analysis (LCA) and latent profile analysis (LPA), are increasingly popular in recent years. Researchers often add covariate variables (i.e., predictor and distal variables) into LCA and LPA models. This kind of models are also called regression mixture models. In this paper, we introduce several new methods. Those methods include (1) the LTB method proposed by Lanza, Tan and Bray (2013) to model categorical outcome variables; and (2) the BCH method proposed by Bolck, Croon and Hagenaars (2004) to deal with continuous distal variables. Using an empirical example, we demonstrate the process of analyses in Mplus. The future directions of those new methods were also discussed.
Subjects: Psychology >> Social Psychology submitted time 2023-03-27 Cooperative journals: 《心理学报》
Abstract： Impulsivity is a typical characteristic of drug addiction. In addition to the problems of inhibition and executive control, the driving force from multiple dimensions is also an important reason for impulsive drug use. The psychological drive stems from a variety of sources, including reward effect, S-R related cue response through conditioning. Low levels of inhibition are insufficient to resist the effects of the drive. This leads to an unbalanced state, which results in habitual behavior tendency. Impulsivity has both a behavioral and neural basis. Although impulsivity may be a precursor of drug use, long-term use may also damage brain structures and functions related to the inhibition of impulsive behavior. There is an open question about whether these structures and functions recover after withdrawal. In this research we used multiple imaging methods to study the extent of recovery in heroin addicts who had been abstinent for several years on average. Thirty-five abstinent heroin addicts (26 males; average period of abstinence = 43.55 months) and 26 healthy controls (26 males) were recruited using advertisements in the community. The heroin group and the healthy control group were compared on multiple measures of brain structure and function related to inhibition using the imaging methods of voxel-based morphometry (VBM), amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo). Based on the amplitude of low-frequency fluctuation (ALFF), right inferior frontal gyrus (15, 60, -6) was selected as the region of interest in which to study functional connectivity (FC). Heroin addicts showed damage in inhibition-related brain structures and functions an average of 44 months after withdrawal, and the extent of damage was correlated with lifetime dose. (1) Compared to the healthy control group, the heroin group had significantly (a) lower gray matter volume (p = 0.03) and lower whole-brain volume (p = 0.05); (b) lower gray matter in the right superior frontal gyrus (pAlphaSim < 0.01); (c) higher regional homogeneity in right posterior central gyrus and lower regional homogeneity in right middle frontal gyrus of the orbitofrontal cortex (pAlphaSim < 0.01); (d) lower amplitude of low-frequency fluctuation in right inferior frontal gyrus of the orbitofrontal cortex and left hippocampus (pAlphaSim < 0.01); (e) higher functional connectivity between right inferior frontal gyrus of the orbitofrontal cortex and the right caudate, and lower functional connectivity between the right inferior frontal gyrus and right middle temporal gyrus as well left precentral gyrus (pAlphaSim < 0.01). (2) Within the heroin group, higher lifetime dose of heroin was significantly associated with lower gray matter volume in the right middle temporal gyrus and left middle cingulate (pAlphaSim < 0.01). The results showed that compared to healthy controls, heroin addicts had significant damage in brain structure and functions related to impulsivity even after an average period of 44 months of abstinence. In addition, the extent of damage was correlated with the lifetime dose of heroin. These results suggest that heroin addicts could continue to show impulsive behavior even after several years of abstinence, perhaps explaining the high rate of relapse in this population. Future research could test this conclusion by examining correlations between brain damage in areas related to inhibition and behavioral measures of impulsivity after a period of abstinence. The current evidence underscores the need to take impulsivity into account in relapse prevention programs for heroin addicts.
Subjects: Psychology >> Social Psychology submitted time 2023-03-27 Cooperative journals: 《心理学报》
Abstract： Under relevant cues, people who are addicted tend to use drugs with little attention, purpose or cognitive effort, conforming to an automated “habitual” response behavior. When the substance is not available, this habitual response behavior will be transformed into psychological craving. A common goal of addiction treatment is to reduce cue-induced reactivity that has automatic and unconscious features. Based on previous research, this study used a self-report questionnaire, two behavioral experiments, and measures of Event-Related Potentials (ERPs) to explore the characteristics and neural mechanisms of cue-induced reactivity in heroin addicts under drug-related cues. On this basis, a training program using Virtual Reality (VR) technology and an Approach-Avoidance task (AAT) was designed to weaken the association between drug-related cues and automatic drug use behavior. In Study 1, the participants (N= 38) were men who were addicted to heroin (n=19) and a matched sample of healthy controls (n = 19). The Visual Analog Craving Scale (VAS) was used to investigate cue-induced reactivity by self-report. We then assessed ERPs to explore the nature and neural mechanism of cue-induced reactivity. We hypothesized that compared to the healthy controls, the participants who were addicted to heroin would show more cue-induced reactivity in the form of automatic response outside of awareness. Corroborating our hypotheses in Study 1, we proceeded to Study 2. N= 60 men who were addicted to heroin were equally divided into a treatment group (n= 30) and a no-treatment group (n= 30). The treatment was VR-AAT training for 10 sessions over the course of two months, with the goal of reducing or eliminating cue-induced reactivity. Before and after the treatment, VR-AAT and the Craving Automatized Scale-Substances (CAS-S) questionnaire were used to test the difference between the two groups. The results showed that 1) In between-group comparisons, VAS scores were higher in the addicts than in the control group. And in Study 2, the within-group analyses showed that self-reports of drug use behavior being “unconscious” and “involuntary” were significantly correlated with the duration of addiction. 2) In within-group analyses, N1 amplitude was smaller, latency was shorter, and reaction time was longer in response to drug-related cues versus neutral cues. Other between-group analyses of the ERP data, addicts demonstrated smaller N1 amplitude and longer reaction time in response to drug-related cues compared to the healthy controls, and these differences were concentrated in the central regions of the brain (i.e., the parietal lobe). 3) After the VR-AAT training, the physiological index (based on temperature, diastolic pressure and systolic pressure) decreased significantly, and the coefficient of approach bias of AAT [(Avoid behavior RTs drug-related- Approach behavior RTs drug-related) - (Avoid behavior RTs neutral- Approach behavior RTs neutral)] was significantly smaller than before training. The results were the same at a two-month follow-up. Our findings revealed that cue-induced reactivity showed characteristics of being automatic and unconscious, with greater N1 reactivity in sensorimotor and related brain areas. The VR-AAT training was effective in reducing cue-induced reactions among men addicted to heroin, suggesting that this method has potential applied value in treating heroin addiction and in designing relapse prevention programs. This research contributes to the addiction literature in two ways. First, AAT training has been used in the treatment of alcohol addiction, but not for other forms of addiction. This is the first research to use AAT training to treat heroin addiction. Second, the treatment in the current study is the first one to combine AAT with virtual reality technology. The VR-AAT method might also be a feasible approach for other substance abuse treatments, although more experimental evidence would be needed to support this. One limitation of this study was that the basis of automatic drug use behavior and automatic refusing drug use behavior cannot be distinguished. This issue can be investigated in future research.
Subjects: Psychology >> Applied Psychology submitted time 2022-04-13
Abstract：
Under relevant cues, people who are addicted tend to use drugs with little attention, purpose or cognitive effort, conforming to an automated "habitual" response behavior. When the substance is not available, this habitual response behavior will be transformed into psychological craving.
A common goal of addiction treatment is to reduce cue-induced reactivity that has automatic and unconscious features. Based on previous research, this study used a self-report questionnaire, two behavioral experiments, and measures of Event-Related Potentials (ERPs) to explore the characteristics and neural mechanisms of cue-induced reactivity in heroin addicts under drug-related cues. On this basis, a training program using Virtual Reality (VR) technology and an Approach-Avoidance task (AAT) was designed to weaken the association between drug-related cues and automatic drug use behavior.
In Study 1, the participants (N = 38) were men who were addicted to heroin (n =19) and a matched sample of healthy controls (n = 19). The Visual Analog Craving Scale (VAS) was used to investigate cue-induced reactivity by self-report. We then assessed ERPs to explore the nature and neural mechanism of cue-induced reactivity. We hypothesized that compared to the healthy controls, the participants who were addicted to heroin would show more cue-induced reactivity in the form of automatic response outside of awareness.
Corroborating our hypotheses in Study 1, we proceeded to Study 2. N = 60 men who were addicted to heroin were equally divided into a treatment group (n = 30) and a no-treatment group (n = 30). The treatment was VR-AAT training for 10 sessions over the course of two months, with the goal of reducing or eliminating cue-induced reactivity. Before and after the treatment, VR-AAT and the Craving Automatized Scale-Substances (CAS-S) questionnaire were used to test the difference between the two groups.
The results showed that 1) In between-group comparisons, VAS scores were higher in the addicts than in the control group. And in Study 2, the within-group analyses showed that self-reports of drug use behavior being "unconscious" and "involuntary" were significantly correlated with the duration of addiction. 2) In within-group analyses, N1 amplitude was smaller, latency was shorter, and reaction time was longer in response to drug-related cues versus neutral cues. Other between-group analyses of the ERP data, addicts demonstrated smaller N1 amplitude and longer reaction time in response to drug-related cues compared to the healthy controls, and these differences were concentrated in the central regions of the brain (i.e., the parietal lobe). 3) After the VR-AAT training, the physiological index (based on temperature, diastolic pressure and systolic pressure) decreased significantly, and the coefficient of approach bias of AAT [(Avoid behavior RTs drug-related -Approach behavior RTs drug-related) - (Avoid behavior RTs neutral - Approach behavior RTs neutral)] was significantly smaller than before training. The results were the same at a two-month follow-up.
Our findings revealed that cue-induced reactivity showed characteristics of being automatic and unconscious, with greater N1 reactivity in sensorimotor and related brain areas. The VR-AAT training was effective in reducing cue-induced reactions among men addicted to heroin, suggesting that this method has potential applied value in treating heroin addiction and in designing relapse prevention programs. This research contributes to the addiction literature in two ways. First, AAT training has been used in the treatment of alcohol addiction, but not for other forms of addiction. This is the first research to use AAT training to treat heroin addiction. Second, the treatment in the current study is the first one to combine AAT with virtual reality technology. The VR-AAT method might also be a feasible approach for other substance abuse treatments, although more experimental evidence would be needed to support this. One limitation of this study was that the basis of automatic drug use behavior and automatic refusing drug use behavior cannot be distinguished. This issue can be investigated in future research.
Peer Review Status:
Awaiting Review
Subjects: Psychology >> Clinical and Counseling Psychology submitted time 2021-11-19
Abstract： " Substance addicts show significant impulsivity, which manifests as substance abuse and difficulty in withdrawing. In addition to the problems of inhibition and executive control, driving force from multiple psychological dimensions is also an important reason for impulsive substance use. This drive stems from a variety of sources, including reward effect, S-R related cue response through conditioning and sensation-seeking personality trait. Low levels of inhibition are insufficient to resist the effects of the drive. Consequently, this unbalanced state will lead to a habitual tendency in behaviour or compulsion to use substances under addicts’ craving. These two types of behavior are the manifestation of addictive impulsivity. "
Subjects: Psychology >> Applied Psychology Subjects: Psychology >> Clinical and Counseling Psychology submitted time 2021-03-26
Abstract： "
Peer Review Status:Awaiting Review
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