Onset Of Drug Use Research Articles

Affective neuroscience personality traits in opioid use disorder patients: The relationship with earlier onset of substance use, the severity of addiction, and motivational factors to quit opiate use.

This study aims to explore the relationship between affective personality traits and opioid use disorder (OUD), including factors such as motivation to quit, addiction severity, and age of onset of drug use. This study included 141 patients with opioid addiction (OAP) and 160 age- and sex-matched healthy controls (HC). OAP were interviewed and diagnosed according to DSM-5 criteria. HC were screened for past or current drug use. Participants completed sociodemographic forms and the Affective Neuroscience Personality Scale (ANPS), and the OAP group also completed the Addiction Profile Index (API). SEEK, PLAY, and SADNESS were identified as different affective personality traits between OAP and HC groups. Addiction severity was positively correlated with SADNESS and ANGER, while the age of onset of drug use was correlated with ANGER. Risk factors for OA include family history of substance abuse, low education, and low PLAY scores, whereas risk factors for earlier substance use onset are childhood trauma and high ANGER scores. This study highlights the importance of understanding affective personality traits in OUD. These findings may deepen our understanding of the underlying mechanisms of OUD. The identification of these affective systems may have implications for the development of personalized prevention and treatment strategies.

Pattern and Socio-demographic characteristics of Drug Users at the National Drug Law Enforcement Agency (NDLEA) Rehabilitation Facility, Port Harcourt

Background: Substance abuse particularly among young people has become a large phenomenon globally affecting all segments of society. The abuse of alcohol, tobacco, cannabis and other psychoactive drugs among young people has become an issue of public health concern with untold negative consequences on human existence. Aim: This study sought to examine the sociodemographic profiles and patterns of drug use among drug users at the NDLEA Rehabilitation Facility, Port Harcourt. Materials and Methods: This was a descriptive cross-sectional study conducted among inmates of the National Drug Law Enforcement Agency (NDLEA), Port Harcourt. A structured questionnaire covering socio-demographic characteristics and other factors were self-administered to inmates of the facility, who have been brought by their relative for addiction care over a period of 3 years (2017 to 2020). Ethical approval was obtained from the ethical committee of the University of Port Harcourt Teaching Hospital and approval was obtained from the NDLEA Authority. All other ethical provisions were followed. Descriptive statistics was used to analyzed the data. Data were analyzed with number count, percentage, and then Chi-square of independence. Results: Majority of the drug users were male (98,8%), single (72.5%), unemployed (27.5%) and apprentice (40.0%), between the ages of 15 and 35 (67.5%) and with tertiary education. Cannabis was the most consumed drug (75.7%), followed by nicotine (30.8%) alcohol (28.3%), cocaine (27.4%) and heroine (25.8%). Majority of the users were introduced to drug by friends and family members and referred to the feeling they got on the first day of use as high and happy. Majority had 15 to 25 years as age of onset of drug use and there were no family history of psychoactive substance use or mental illness. Conclusion: Substance use is common among young people between the ages of 26 and 30, single, with higher level of education and low-income earners. Majority use illicit drugs, which they started at early age of 15 to 25 and introduced to by friends and family members. Improvement in socio-economic status of adolescents and sustained public health enlightenment will help to reduce the rising prevalence of drug use.

An uncharted territory of sexualized drug use: exploring the dynamics of chemsex among young and adolescent MSM including self-identified gay men in urban Dhaka, Bangladesh.

Global and local literature depicted the pervasiveness of chemsex among men who have sex with men (MSM), yet there is limited evidence on adolescents and youth. Though literature showed their engagement in chemsex, further exploration is warranted about their socio-sexual contexts and implications. Therefore, this article explored the contexts and implications of chemsex on young and adolescent MSM. This article is extracted from qualitative research evidence, and research data are triangulated by programmatic evidence on adolescent and young MSM from two ongoing pilot interventions. The key motivational factors for engaging in chemsex were primarily rooted in the dynamics of their peer networks. Specifically, the onset of drug use is predominantly attributed to curiosity toward experimentation with methamphetamine, peer influence, propensity to lose weight, and increasing courage to approach potential sexual partners. Moreover, they continued taking drugs as it enhanced their sexual performance, thus perpetuating chemsex. Additionally, the findings revealed several sexual implications of methamphetamine, e.g., bolstering their sexual "stamina," increasing their propensity toward sexual violence, and reducing their decision-making abilities and judgment, thus collectively decreasing condom use. In essence, chemsex is considerably driven by their socio-sexual contexts, thus perpetuating sexual risk behaviors and compromising sexual health outcomes. Therefore, harm reduction interventions targeted need to be designed keeping in mind their socio-sexual dynamics and age.

Effects of Acute Exercise on Affect, Anxiety, and Self-Esteem in Poly-Substance Dependent Inpatients

Introduction: Negative affect and anxiety frequently precede the onset of drug use in those with substance use disorder (SUD). Low self-esteem may increase the risk of relapse. We examined the short-term effects of exercise on affect, anxiety, and self-esteem in inpatients with poly-SUD. Methods: This is a multicenter randomized control trial (RCT) with a crossover design. Thirty-eight inpatients (37.3 ± 6.4 years; 84% male) from three clinics participated in 45 min of soccer, circuit training, and control condition (psychoeducation) in a random order. Positive and negative affect (PANAS), state anxiety (single item), and self-esteem (Rosenberg SE-scale) were measured immediately before, immediately after, 1-h, 2-h, and 4-h post-exercise. Heart rate and ratings of perceived exertion were taken. Effects were assessed using linear mixed effects models. Results: Compared to the control condition, there were significant post-exercise improvements in positive affect (β = 2.99, CI = 0.39: 5.58), self-esteem (β = 1.84, CI = 0.49: 3.20), and anxiety (β = −0.69, CI = −1.34: −0.04) after circuit training (shown) and soccer. Effects persisted 4-h post-exercise. Reductions in negative affect were observed 2-h (circuit training: β = −3.39, CI = −6.35: −1.51) and 4-h (soccer: β = −3.71, CI = −6.03: −1.39) post-exercise, respectively. Conclusion: Moderately strenuous exercise undertaken in naturalistic settings may improve mental health symptoms in poly-SUD inpatients for up to 4-h post-exercise.

Reincidencia delictiva en adolescentes colombianos: factores de riesgo y protectores relacionados

Research with adolescent offenders is concerned with identifying risk and protective factors that influence recidivism and desistance from crime. A quantitative and cross-sectional investigation designed to examine the influence of risk and protective factors on recidivism in Colombian adolescents is presented. In seven regions of Colombia, a convenience sample was obtained, and 646 adolescents aged 14 to 19 years (M = 17.08; SD: 1.23; 15 % girls) belonging to the Sistema de Responsabilidad Penal para Adolescentes (SRPA) participated. The Communities That Care Youth Survey (CTC-YS) was used for the evaluation. It evaluated a broad set of risk and protective factors identified through the community, school, family, peer group, individual conditions, and behavioral outcomes, including drug use, antisocial behavior, and delinquency. Descriptive analyses were conducted, and all CTC-YS factors were correlated with antisocial behavior. The results show varying degrees of relationship between the factors assessed and antisocial behavior. Binary logistic regression was used to determine which risk and protective factors influence recidivism. It was noted that favorable parental attitudes towards drug use and antisocial behavior, early onset of drug use, low school engagement, and interaction with antisocial peers increases the probability of recidivism. Recidivism was identified as being affected by, among other factors, favorable parental attitudes toward drug use and antisocial behavior, early onset of drug use, and low school engagement. It was also observed that beliefs in a moral order, opportunities for prosocial school participation and lower drug use frequency reduce the probability of recidivism. According to the results, the factors that influence criminal recidivism are multiple, and social, family, school, and individual factors need to be addressed. The need to intervene in attitudes favorable to antisocial behavior on the part of parents, strengthen school services, and carry out treatment for drug use to favor the reduction of recidivism in Colombian adolescents is discussed. https://doi.org/10.16888/interd.2023.40.1.25

Prefrontal-habenular microstructural impairments in human cocaine and heroin addiction

The habenula (Hb) is central to adaptive reward- and aversion-driven behaviors, comprising a hub for higher-order processing networks involving the prefrontal cortex (PFC). Despite an established role in preclinical models of cocaine addiction, the translational significance of the Hb and its connectivity with the PFC in humans is unclear. Using diffusion tractography, we detailed PFC structural connectivity with the Hb and two control regions, quantifying tract-specific microstructural features in healthy and cocaine-addicted individuals. White matter was uniquely impaired in PFC-Hb projections in both short-term abstainers and current cocaine users. Abnormalities in this tract further generalized to an independent sample of heroin-addicted individuals and were associated, in an exploratory analysis, with earlier onset of drug use across the addiction subgroups, potentially serving as a predisposing marker amenable for early intervention. Importantly, these findings contextualize a plausible PFC-Hb circuit in the human brain, supporting preclinical evidence for its impairment in cocaine addiction.

Sexual Orientation and Age of First Drug Use Among Adults in the United States

Background Early onset of drug use could lead to long-term impairments, and research suggests that substance use and substance use disorders are more common among lesbian, gay, and bisexual (LGB) individuals. We sought to determine whether adults of different sexual identities were at differential risk for an earlier onset of drug use. Methods We examined data from adults participating in the five waves (2015–2019) of the National Survey on Drug Use and Health, a nationally representative sample of noninstitutionalized adults in the United States. We determined whether current sexual identity was associated with retrospectively reported age of the first use of marijuana, cocaine, inhalants, ecstasy, and methamphetamine. Results Compared to heterosexual individuals of the same sex, gay men had a later age of onset of use of all five drugs examined (marijuana, cocaine, inhalants, ecstasy, and methamphetamine) and bisexual men had a later onset of marijuana and inhalant use. Bisexual women had earlier age of onset for marijuana, cocaine, and ecstasy use. When examining early initiation (prior to age 15), both lesbian and bisexual women had greater odds of early initiation for marijuana, cocaine, and ecstasy; bisexual men had greater odds of early initiation for cocaine. Gay men had lower odds of initiation prior to age 15 for marijuana, inhalants, and methamphetamine. Conclusions Current sexual identity is a correlate of earlier onset drug use. Longitudinal research is needed to further examine such associations as sexual identity can shift over time. Results are discussed in relation to prevention efforts aiming younger LGB persons.

Transition from first illegal drug use to first injection among people who inject drugs in Northern Mexico: A retrospective survival analysis

Introduction. There is little information in Mexico about the transition to injecting drugs among drug users in cities other than Tijuana. Objective. We compare characteristics of the onset of drug use and first injection among people who inject drugs (PWID) from Ciudad Juárez and Hermosillo, two cities of Northern Mexico and identify factors associated with faster rates of transition from first drug use to the first injection. Method. 841 PWID were interviewed in 2012 in Ciudad Juárez (n = 445) and Hermosillo (n = 396). Using lifetables, we describe timing at the onset of drug use and first injection. Cox regression analysis was used to determine factors associated with the transition hazard to first injection. Results. Median age at onset of drug use was 15.5 years old (standard deviation [SD] = 5.73). The median age at first injection was 21.30 (SD = 7.22). The median duration-time between first drug use and transition to injection was 4.8 years (SD = 5.6). Controlling for sociodemographics, factors that increase the hazard of transitioning to injection are age at onset of drug use (adjusted-hazard-rate [AHR] = 1.04, 95% confidence-interval CI [1.03, 1.05], p#abr#.01) having used cocaine, heroin, or methamphetamine at the onset of drug use (AHR = 1.14, 95% CI [1.03, 1.27], p = .01), and having received assistance at first injection (AHR = 1.25, 95% CI [1.17, 1.33], p#abr#.01). Discussion and conclusion. Results show the need to enhance harm reduction programs among non-injecting drug users so as to prevent the spread of injecting drugs in Mexico.

Do cannabis and amphetamine use in adolescence predict adult life success: a longitudinal study

Background While some studies have reported that early age of onset of cannabis and amphetamine use predicts a range of adverse outcomes, these findings are rarely adjusted for other predictors of adverse outcomes or subsequent drug use over the adult life course. These studies have not addressed the possibility that it is subsequent rather than early age of onset of drug use that may predict adult life success. Methods Data are from the Mater-University of Queensland Study of Pregnancy (MUSP). At 21 years, respondents self-reported their use of cannabis and amphetamines and completed the Composite International Diagnostic Interview (CIDI) on lifetime ever use of cannabis and amphetamines. At 30 years, respondents self-reported their past-year use of cannabis and amphetamines. The outcome measure is a composite measure of life success at the 30-years follow-up. Associations are adjusted for covariates at the 14-year follow-up. Results Adolescent behavior problems predict drug use at 21 years, drug use and life success at 30 years. The association between early age of onset cannabis use, amphetamine use and cannabis and amphetamine use and adult life success is not statistically significant once adjusted for cannabis and amphetamine use at the 30-year follow-up. Concurrent cannabis use at the 30-year follow-up is strongly related to life success. Conclusions In a community sample, cannabis as well as cannabis and amphetamine use and/or use disorder in the adolescent period does not appear to predict life success in adulthood for those whose use has ceased prior to 30 years of age.

Exploring the clinical variables among drug-dependent HIV-Positive patients: Implications for treatment strategies.

This study explored the profile of HIV positive patients seeking treatment at a tertiary care addiction treatment facility. A retrospective study was done to collet detailed information on clinical characteristics: drug use (type, age of initiation, duration), general medical condition and past treatment history. The study included 138 patients with mean (SD) age 30.2 (8.3) years. Opioid dependence with injecting drug use (IDU) was diagnosed in 97% of the patients. The median age of injecting onset was 24.5 years (IQR 20-31 years). The most frequently injected substances were pheniramine (60.1%) and buprenorphine (59.4%). Past treatment seeking was reported by 57% patients and interestingly they were less likely to present any medical condition (2 =69.611, p < 0.001). Variability in the age of onset of drug use indicates the need for broad based approach to prevent IDU and motivation to seek treatment may lead to better health conditions.

Frequency and recency of non-medical opioid use and death due to overdose or suicide among individuals assessed for risky substance use: A national registry study in Sweden

Sweden and many other countries have experienced increases in suicide and accidental overdose deaths. An analysis examined the associations between recency of non-medical opioid misuse and frequency of use of non-medical opioids with death due to either suicide or accidental overdose within a sample of 15,000 Swedish adults who completed an Addiction Severity Index (ASI) assessment for risky substance use or a substance use disorder. Methods and materialsSuicide (n = 136) and death due to overdose (n = 405) were identified in the official Cause of Death Registry from the Swedish National Board of Health and Welfare. Control variables included demographic characteristics and risks associated with either overdose or suicide. Cox regression analyses controlled for variables statistically significantly at the bivariate level. ResultsAt the multivariable level: a) a higher (modified) ASI Composite Score for mental health; b) history of suicide attempt; c) having used non-medical opioids for 1–2 times per week for at least a year; d) history of injection drug use; and, e) early onset of drug use, were all significantly and positively associated with death due to suicide. At the multivariable level: a) a higher the revised ASI Composite Score for mental health; b) recency of use of non-medical opioids; c) frequency of non-medical opioid use; d) being a male; and e) being of ages 18–24 years compared to ages 43–51 years were all positively and significantly associated with death due to accidental overdose. ConclusionThese findings underscore the need to integrate mental health and substance use disorder treatment and provide suicide and overdose prevention interventions for individuals with an opioid use disorder. Recency and frequency of non-medical opioids were only associated with death due to overdose and not suicide. However, other drug use related variables (using opioids 1–2 times per week for at least a year, early onset of drug use and drug injection) were significantly associated with death due to suicide.

Age at onset of drug use and aggressive behavior: The role of internal and environmental factors

Age at onset of drug use and aggressive behavior: The role of internal and environmental factors

The Effects of the COVID-19 Pandemic on the Risk of Youth Substance Use

The Effects of the COVID-19 Pandemic on the Risk of Youth Substance Use

The Effects of Childhood Trauma on Drug Use

Exposure to childhood physical abuse, sexual abuse, emotional abuse, and neglect have been found to have a positive association with drug use. Various studies have demonstrated how individuals may turn to drugs as a form of coping. However, this is a negative form of coping, which can take a toll on one’s mental state and even impact families and society. Studies have reported that a higher number of adverse childhood experiences (ACEs) have a stronger association with substance use later in life [1,3]. Recent research has also demonstrated those who experienced childhood neglect also displayed anxiety or depression, which might suggest a reason for the connection between the negligence and drug use [14]. There is also research that shows that childhood maltreatment could influence one’s susceptibility to drugs and the structural remodeling of the brain [4]. Various types of drugs have been used in association with childhood trauma; however, no single drug was reported to have a greater association than the others. Substance abuse has been a rising issue over the years. With the understanding that childhood trauma could contribute to the onset of drug use, it is essential to gain a better knowledge of the specific types of substance abuse linked to childhood trauma. Future examination of this topic can help raise awareness and educate society on the effects of childhood trauma and how to prevent drug use associated with it.

Positron Emission Tomography: Updates on Imaging of Addiction.

Positron Emission Tomography: Updates on Imaging of Addiction.

Could the link between drug addiction in adulthood and substance use in adolescence result from a blurring of the boundaries between incentive and hedonic processes?

There is a broad consensus that the development of drug addiction in adulthood is closely linked to the onset of drug use in adolescence. However, the relationship between drug exposure during adolescence and subsequent vulnerability to addiction is yet to be fully understood. This review will first use evidence from adult studies on reward and addiction to give an up-to-date reference point of normal reward-circuitry and the maladaptive changes that later occur in addiction. This will then be compared with current evidence from adolescent studies on reward-circuitry. Similarities between the reward processes governing characteristic behavioral traits in adolescence and the reward profile in adult addiction could help to explain why the risk of later developing addiction is increased when substance use is initiated in adolescence. We argue that the age of onset is a major risk factor in the development of substance use disorder due to a blurring of the boundaries between incentive and hedonic processes, which occurs during adolescence. A deeper understanding of the processes that mediate this blurring could open new avenues for the prevention and treatment of adult drug addiction.

Association of Cohort and Individual Substance Use With Risk of Transitioning to Drug Use, Drug Use Disorder, and Remission From Disorder

Limited empirical research has examined the extent to which cohort-level prevalence of substance use is associated with the onset of drug use and transitioning into greater involvement with drug use. To use cross-national data to examine time-space variation in cohort-level drug use to assess its associations with onset and transitions across stages of drug use, abuse, dependence, and remission. The World Health Organization World Mental Health Surveys carried out cross-sectional general population surveys in 25 countries using a consistent research protocol and assessment instrument. Adults from representative household samples were interviewed face-to-face in the community in relation to drug use disorders. The surveys were conducted between 2001 and 2015. Data analysis was performed from July 2017 to July 2018. Data on timing of onset of lifetime drug use, DSM-IV drug use disorders, and remission from these disorders was assessed using the Composite International Diagnostic Interview. Associations of cohort-level alcohol prevalence and drug use prevalence were examined as factors associated with these transitions. Among the 90 027 respondents (48.1% [SE, 0.2%] men; mean [SE] age, 42.1 [0.1] years), 1 in 4 (24.8% [SE, 0.2%]) reported either illicit drug use or extramedical use of prescription drugs at some point in their lifetime, but with substantial time-space variation in this prevalence. Among users, 9.1% (SE, 0.2%) met lifetime criteria for abuse, and 5.0% (SE, 0.2%) met criteria for dependence. Individuals who used 2 or more drugs had an increased risk of both abuse (odds ratio, 5.17 [95% CI, 4.66-5.73]; P < .001) and dependence (odds ratio, 5.99 [95% CI, 5.02-7.16]; P < .001) and reduced probability of remission from abuse (odds ratio, 0.86 [95% CI, 0.76-0.98]; P = .02). Birth cohort prevalence of drug use was also significantly associated with both initiation and illicit drug use transitions; for example, after controlling for individuals' experience of substance use and demographics, for each additional 10% of an individual's cohort using alcohol, a person's odds of initiating drug use increased by 28% (odds ratio, 1.28 [95% CI, 1.26-1.31]). Each 10% increase in a cohort's use of drug increased individual risk by 12% (1.12 [95% CI, 1.11-1.14]). Birth cohort substance use is associated with drug use involvement beyond the outcomes of individual histories of alcohol and other drug use. This has important implications for understanding pathways into and out of problematic drug use.

Tempéraments affectifs des toxicomanes : étude cas-témoins

IntroductionThe study of affective temperaments is a dimensional approach to personality that would provide a better understanding of the emergence of psychopathological disorders including addictive behaviors. However, in the literature, there is a lack of studies focusing on the links between this type of disorder and affective temperaments. Our objectives were to study the distribution of the five known affective temperaments in a group of drug addicts compared to a control group, and to identify sociodemographic and clinical factors associated with emotional traits. MethodsThis was a case-control study carried out in the drug abuse prevention center “ATUPRET” of Sfax in Tunisia. It included 50 drug addicts, all male, and 50 healthy control subjects matched for age (P=0.22), marital status (P=0.28), socioeconomic level (P=0.36) and educational level (P=0.95). Sociodemographic data were collected through an interview for drug addicts hospitalized in this center while clinical data were collected from medical records. The TEMPS-A questionnaire, 110 questions validated Tunisian version, has been used to evaluate five affective temperaments. ResultsThe average age of drug addicts was 32.98 years (19–59 years) and the average age at onset of drug use was 20.36 years (12–52 years). Among drug users, the highest mean scores were observed for hyperthymic temperament (13.68±4.20), followed by cyclothymic (13.14±4.89), anxious (11.32±6.00) and depressive (11.02±3.65) ones. The lowest mean score was for irritable temperament (10.14±3.95). All of these scores, except that of cyclothymic temperament, were significantly higher than in the control group (P<0.01). The age of drug addicts was negatively correlated with cyclothymic (P=0.023) and irritable (P=0.035) temperament scores. These two temperaments were more dominant in the group of drug addicts with post-secondary education (P respectively 0.035 and 0.002). The age of onset of psychoactive substance use was negatively correlated with irritable temperament (r=−0.355, P=0.012). Cyclothymic temperament was correlated with alcohol dependence (P=0.03) and psychiatric comorbidity (P=0.01) among drug addicts. ConclusionThe present study provides support for the existence of temperamental dysregulation in drug-addicted patients. This result leads us to suggest that affective temperaments are implicated as a potential endophenotype and may represent a marker for the identification of persons vulnerable to drug use. These affective temperaments also appear to influence clinical features of drug addiction.

The Effect of Childhood Conduct Problems on Early Onset Substance Use: An Examination of the Mediating and Moderating Roles of Parenting Styles.

This study examines the role that effective parenting plays in the relationship between childhood conduct problems and the early onset of drug use. Effective parenting is posited to have a direct protective effect on drug use, a moderating effect on the relationship between conduct problems and early onset, and mediate the relationship between conduct problems and early onset. Two-generational panel data are used to examine these relationships among 263 parent–child dyads. Support is found for the direct protective effect of effective parenting on early onset .and for a partial mediating effect of parenting in the relationship between conduct problems and early onset. There was no support found for parenting moderating the risk that is posed by having childhood conduct problems. Implications for preventing childhood conduct problems from resulting in early onset of drug use through enhancing efforts to help parents cope with such problems are discussed.

A Research of Methamphetamine Induced Psychosis in 1,430 Individuals With Methamphetamine Use Disorder: Clinical Features and Possible Risk Factors.

Background and Aims: Methamphetamine (MA) abuse is commonly associated with the development of psychotic symptoms. The predictors and related risk factors of MA induced psychosis (MIP) are poorly understood. We investigated the occurrence of MIP, and analyzed the clinical features and possible risk factors among individuals with MA use disorderMethod: One thousand four hundred and thirty participants with MA use disorder were recruited from compulsory rehabilitation centers in Shanghai. A structured questionnaire including demographic characteristics, drug use history, visual analog scales, Beck Depression Inventory-13 (BDI-13), and Hamilton anxiety scale-14 (HAMA-14) were used to collect clinical related information. Fifty-six participants had accomplished the test of CogState Battery.Results: Among the 1430 individuals with MA use disorder, 37.1% were diagnosed as MIP according DSM-IV. There were significant differences in age, marital status, age of drug use onset, MA use years, Average MA use dose, interval of MA use, maximum dose, concurrent use of alcohol, and other drugs, VAS score, MA dependence, BDI-13 scores, HAMA-14 scores, verbal learning memory, and visual learning memory between the MIP group and the none MIP group (P < 0.05). The age of drug use onset (OR = 0.978, p = 0.011), average drug use dose (OR = 1.800, p = 0.015), craving score (OR = 1.069, p = 0.031), MA dependence (OR = 2.214, p < 0.001), and HAMA scores (OR = 1.028, p < 0.001) were associated to MIP.Conclusion: Individuals with MIP had more severe drug use problems, emotional symptoms and cognitive impairment. Earlier onset of drug use, higher quantity of drug use, higher craving, middle or severe drug use disorder and more anxiety symptoms may be related risk factors of MIP.