Suicidal ideation, antidepressive medication and car crash injury

Effects of insomnia on risky driving behavior among bus drivers: The mediating effect of mental health

Crashes caused by problems with bus drivers' physical and mental health have increased in frequency in recent years. Insomnia, a common type of sleep problem, has significant positive relationships with both crash risk and mental health problems, especially anxiety and depression, which are themselves associated with driving behavior. However, few studies have conducted analysis on sleep-related problems and mental health exclusively on bus drivers, nor on how these problems influence driving performance. Thus, this study explored the effect of insomnia and mental health on bus drivers' risky driving behavior and evaluated the interaction of four variables: insomnia, anxiety, depression, and risky driving behavior. The survey-based investigation was conducted in a bus company in Suzhou, China, with 1,295 bus drivers participating. Insomnia, anxiety, and depression were self-reported based on professional mental health scales and risky driving behaviors were measured by the Driver Behavior Questionnaire. Two mediation models and a chain mediation model were developed to examine relationships among the bus drivers' insomnia, anxiety, depression, and risky driving behavior. Results revealed that (a) bus drivers less than 31 years old, drivers with more than 11 years' experience driving buses, and those with crash and violation involvement within three years demonstrated more severe degrees of insomnia, anxiety, depression, and risky driving behavior; (b) there were significant positive correlations and interactions among the four variables. Results specifically related to the interaction among variables include findings that (a) anxiety mediated between insomnia and risky driving behavior; (b) depression mediated between insomnia and risky driving behavior; and (c) anxiety affected bus drivers' risky driving behavior primarily though depression. The findings in this study indicate the importance of regular physical and mental health examination of bus drivers and suggest that interventions focused on insomnia and mental health problems may be helpful to reduce risky driving behaviors of bus drivers both directly and indirectly.

Association of driving while intoxicated and suicide ideation and attempts in South Korea: a study in a nationally representative sample

Evidence indicating driving as a means for suicide has been consistently reported. However, there have been few reported studies examining the association between driving while intoxicated (DWI) and suicide. We aimed to investigate the associations between DWI and suicide ideation and suicide attempts taking into account the frequency and amount of alcohol consumption. This cross-sectional study used data from semi-structured, face-to-face interviews conducted with a nationally representative sample of the Korea Community Health Survey in 2009, 2013, and 2017. The study included 267,457 adult participants who drank alcohol at least once and had driven a motor vehicle at least once in the preceding year. The DWI group comprised participants who had driven under the influence of alcohol at least once in the preceding year. The associations between DWI and suicide ideation and suicide attempts were examined using a logistic regression model, adjusting for the frequency and amount of alcohol consumption and history of depressive episodes in the preceding year. The role of DWI as a risk factor for suicide was also examined in an analysis stratified by the frequency and amount of alcohol consumption. The DWI group included 39,062 (14.6%) subjects, who were at higher risk for suicide ideation (adjusted odds ratio [aOR] = 1.91; 95% CI 1.81-2.01) and suicide attempts (aOR = 1.56; 1.27-1.92) than those not involved in DWI. Increased risks of suicide ideation and suicide attempts were observed in most strata in the stratified analysis. People who engage in DWI may have an increased risk of suicide ideation and suicide attempts; this relationship was generally observed regardless of the frequency and amount of alcohol consumption.

A Systematic Review of the Risks of Motor Vehicle Crashes Associated with Psychiatric Disorders

OBJECTIVE

Psychiatric disorders and their treatments have the potential to adversely impact driving skills. However, it is unclear to what extent this poses a public health risk by increasing the risk of motor vehicle crashes (MVCs). The aim of this systematic review was to synthesize and critically appraise evidence on the risk of MVC for drivers with psychiatric disorders.

METHOD

We conducted a systematic review of the MVC risk associated with psychiatric disorders using seven databases in November 2019. Two reviewers examined each study and extracted data. The National Heart, Lung, and Blood Institute Quality Assessment tools were used to assess each study's quality of evidence.

RESULTS

We identified 24 studies that met the inclusion criteria, including eight cohort, 10 case-control, and six cross-sectional designs. Quality assessment ratings were "Good" for four studies, "Fair" for 10, and "Poor" for 10. Self-report or questionnaires were used in place of objective measures of either MVC, psychiatric disorder, or both in 12 studies, and only seven adjusted for driving exposure. Fifteen studies reported an increased risk of MVC associated with psychiatric disorders, and nine did not. There was no category of disorder that was consistently associated with increased MVC risk.

CONCLUSION

The available evidence is mixed, not of high quality, and does not support a blanket restriction on drivers with psychiatric disorder. An individualized approach, as recommended by international guidelines, should continue. Further research should include objective assessments of psychiatric disorders and MVC risk and adjust for driving exposure.

An overview of suicides related to motor vehicles

Although vehicles may be used in a wide variety of suicides, this has not been a focus in the forensic literature. Thus, an analysis of coronial autopsy reports at Forensic Science SA, Adelaide, South Australia over a 16-year period from January 2005 to December 2020 was undertaken to provide an overview of cases in which it was considered that a vehicle had been integral to the successful completion of a suicide. De-identified details were collected from all cases in which a vehicle had facilitated or been used as a method of suicide. A number of different types of vehicle-related suicide methods were identified, including cases where vehicles had been used as secure places for suicide or where the vehicle had been used to cause significant blunt force trauma or to enter a lethal environment such as water. Specific examples were taken from the following categories: (1) inhalation of gas, (2) drug toxicity, (3) hanging or ligature strangulation, (4) self-immolation, (5) drowning, (6) vehicle collision, (7) driving off a cliff, (8) jumping or lying in front of a vehicle and (9) the use of more than one method (i.e. complex). This report is not intended to provide an epidemiological analysis of car-related suicides. Instead, the details of selected cases have been used to illustrate the spectrum of methods that may be used in vehicle-assisted suicides.

Characteristics of suicide-related crashes and their potential interventions: A literature review

OBJECTIVE

To develop countermeasures to decrease road trauma, it is essential to increase our understanding of fatal and injury crashes with suicidal intent. As suicide-related crashes can be difficult to identify it seems likely suicide-related road fatalities and injuries are under-reported. Under-reported crashes may lead to two policy issues: these types of casualty crashes may not receive adequate funding for countermeasure development and implementation due to not having a sufficient evidence-basis to justify allocation of resources, and may be miscategorized as having other factors contributing to the crashes, thus resources may be incorrectly allocated to countermeasures to address these other factors. This paper seeks to develop and document characteristics and potential countermeasures to identify and prevent such crashes.

METHODS

Two literature reviews of peer-reviewed journal manuscripts were performed to identify suicide-crash characteristics and potential countermeasures and strategies. Of 61 peer-reviewed journal manuscripts identified from the literature searches, 17 manuscripts fit the criteria and were reviewed. Information regarding the characteristics of suicide-related crashes, as well as potential strategies and countermeasures were gleaned from these manuscripts.

RESULTS

A list of characteristics was developed, underpinning development of a methodology to identify these types of crashes. Strategies and countermeasures recommended by international (road-) agencies to identify and prevent suicide-related crashes were documented and discussed.

CONCLUSION

As suicide-related crashes almost always take place in public space, the grief and pain resulting from such crashes not only relates to the victim, the people who knew the victim, but in many cases also involve the general public. It is therefore paramount to start the discussion about suicide-related crashes to increase awareness, increase willingness to establish a reliable data and knowledge base, and encourage help seeking in individuals at increased risk of attempting suicide using this method.

An Evaluation of the Relationship between Mental Disorders and Driving Accidents among Truck Drivers

INTRODUCTION

A review of the existing literature shows the importance of mental health in preventing traffic accidents. Therefore, the current study aims to determine the mentioned mental disorders in relation with the history of accidents among truck drivers.

METHODS

This cross-sectional study was done with two groups of truck drivers (with and without a history of accidents) in Iran. 56 people with a history of accidents and 410 people without a history of accidents participated in this study. At first, using questionnaires, the demographic information of the participants including age, education level, cigarette use, and addiction to drug was collected. Then, the mental disorders of the participants were evaluated by a 71-question, short form of the multidimensional Minnesota Multiphasic Personality Inventory (MMPI). The evaluated disorders are the HS or hypochondria, D or depression, HY or hysteria, Pd or social mental deviation, Pa or paranoia, Pt or mental weakness, Sc or schizophrenia, and Ma or hypomania. The tests used for data analysis include descriptive tests and Chi square.

RESULTS

Man-Whitney U test showed that status of mental disorders, as revealed by the MMPI questionnaire, had a significant difference between the two groups with and without history of driving accidents (P < 0.001). The results showed that mental disorders of depression, hysteria, social mental deviation, paranoia, schizophrenia, and hypomania in individuals with history of driving accidents led to meaningful differences from individuals without history of driving accidents (P < 0.048).

CONCLUSION

The results of the current study showed that generally, individuals with history of driving accidents had significantly more mental disorders than people without history of driving accidents.

A systematic review of evidence for fitness-to-drive among people with the mental health conditions of schizophrenia, stress/anxiety disorder, depression, personality disorder and obsessive compulsive disorder

BACKGROUND

Limited evidence exists regarding fitness-to-drive for people with the mental health conditions of schizophrenia, stress/anxiety disorder, depression, personality disorder and obsessive compulsive disorder (herein simply referred to as 'mental health conditions'). The aim of this paper was to systematically search and classify all published studies regarding driving for this population, and then critically appraise papers addressing assessment of fitness-to-drive where the focus was not on the impact of medication on driving.

METHODS

A systematic search of three databases (CINAHL, PSYCHINFO, EMBASE) was completed from inception to May 2016 to identify all articles on driving and mental health conditions. Papers meeting the eligibility criteria of including data relating to assessment of fitness-to-drive were critically appraised using the American Academy of Neurology and Centre for Evidence-Based Medicine protocols.

RESULTS

A total of 58 articles met the inclusion criteria of driving among people with mental health conditions studied, and of these, 16 contained data and an explicit focus on assessment of fitness-to-drive. Assessment of fitness-to-drive was reported in three ways: 1) factors impacting on the ability to drive safely among people with mental health conditions, 2) capability and perception of health professionals assessing fitness-to-drive of people with mental health conditions, and 3) crash rates. The level of evidence of the published studies was low due to the absence of controls, and the inability to pool data from different diagnostic groups. Evidence supporting fitness-to-drive is conflicting.

CONCLUSIONS

There is a relatively small literature in the area of driving with mental health conditions, and the overall quality of studies examining fitness-to-drive is low. Large-scale longitudinal studies with age-matched controls are urgently needed in order to determine the effects of different conditions on fitness-to-drive.

Depression, antidepressants and driving safety

BACKGROUND

The purpose of this study was to review to review the reported associations of depression and antidepressants with motor vehicle crashes.

PURPOSE

A literature search for material published in the English language between January, 1995, and October, 2015, in bibliographic databases was combined with a search for other relevant material referenced in the retrieved articles.

METHODS

Retrieved articles were systematically reviewed for inclusion criteria: 19 epidemiological studies (17 case-control and 2 cohort studies) fulfilled the inclusion criteria by estimating the crash risk associated with depression and/or psychotropic medications in naturalistic settings.

RESULTS

The estimates of the odds ratio (OR) of crash involvement associated with depression ranged from 1.78 to 3.99. All classes of antidepressants were reported to have side effects with the potential to affect driving safety. The majority of studies of antidepressant effects on driving reported an elevated crash risk, and ORs ranged from 1.19 to 2.03 for all crashes, and 3.19 for fatal crashes. In meta-analysis, depression was associated with approximately 2-fold increased crash risk (summary OR = 1.90; 95% CI, 1.06 to 3.39), and antidepressants were associated with approximately 40% increased crash risk (summary OR = 1.40; 95%CI, 1.18 to 1.66).

CONCLUSION

Based on the findings of the studies reviewed, depression, antidepressants or the combination of depression and antidepressants may pose a potential hazard to driving safety. More research is needed to understand the individual contributions of depression and the medications used to treat depression.

[Driving ability with affective disorders and under psychotropic drugs]

There are only few data available regarding the effects of depressive disorders on road safety due to methodological shortcomings. Patients with acute severe depression or manias are unqualified for driving but after clinical remission driving ability can be attested under psychiatric supervision in most cases. So far there are only few data available about a patient's fitness to drive under psychotropic medication. Regarding the effects of antidepressants on road safety depressed patients obviously benefit from treatment with newer antidepressants; however, at least some subgroups of patients do not reach the performance level of healthy subjects. Approximately 17 % of remission bipolar patients must be regarded as unable to drive and 27 % of patients with schizophrenia on discharge from hospital. Benzodiazepines are clearly associated with increased risk of road traffic accidents. Impaired driving ability of young attention deficit hyperactivity disorder (ADHS) patients is improved under treatment with methylphenidate. Counselling patients with respect to driving ability must be carried out individually taking into account factors of the illness, personality, attitudes and coping strategies as well as different psychopharmacological effects.

Risk of road accident associated with the use of drugs: a systematic review and meta-analysis of evidence from epidemiological studies

This paper is a corrigendum to a previously published paper where errors were detected. The errors have been corrected in this paper. The paper is otherwise identical to the previously published paper. A systematic review and meta-analysis of studies that have assessed the risk of accident associated with the use of drugs when driving is presented. The meta-analysis included 66 studies containing a total of 264 estimates of the effects on accident risk of using illicit or prescribed drugs when driving. Summary estimates of the odds ratio of accident involvement are presented for amphetamines, analgesics, anti-asthmatics, anti-depressives, anti-histamines, benzodiazepines, cannabis, cocaine, opiates, penicillin and zopiclone (a sleeping pill). For most of the drugs, small or moderate increases in accident risk associated with the use of the drugs were found. Information about whether the drugs were actually used while driving and about the doses used was often imprecise. Most studies that have evaluated the presence of a dose-response relationship between the dose of drugs taken and the effects on accident risk confirm the existence of a dose-response relationship. Use of drugs while driving tends to have a larger effect on the risk of fatal and serious injury accidents than on the risk of less serious accidents (usually property-damage-only accidents). The quality of the studies that have assessed risk varied greatly. There was a tendency for the estimated effects of drug use on accident risk to be smaller in well-controlled studies than in poorly controlled studies. Evidence of publication bias was found for some drugs. The associations found cannot be interpreted as causal relationships, principally because most studies do not control very well for potentially confounding factors.

Assessing legal strains and risk of suicide using archived court data

Relatively little is known about legal entanglements and suicide risk. This matched case-control study estimated the risk of suicide associated with legal strains using online court archives, a novel source of exposure data. Court records linked to suicide deaths (N = 315), controls (N = 630), and unintentional injury and poisoning deaths (N = 630) for an urban county from 2000 to 2005 revealed that nearly a third of suicide victims had recent court involvement, twice the proportion among controls. Misdemeanors, car accidents, and foreclosures were each associated with a threefold risk of suicide. Implications for suicide prevention and research are discussed.

Intent in Manner Determination

Manner of death determination is a basic and traditional task for medical examiners. Though it has a history spanning centuries, many facets of manner determination continue to be problematic. Few issues are more vexing than the difficulties in determining intent. A survey of members of the National Association of Medical Examiners was performed to determine current practice and attitudes about the use of intent in manner determination. There were 168 completed responses, representing an approximately 20% response rate. The results reveal significant variation. While the concept of “volition” as distinct from “intent” has been common for over a decade, less than 60% of respondents made the distinction in their practice. There was also wide variation in the degree of certainty practitioners noted they used when determining manner with peaks at between 51-60% and 95-99%. Some of this represents real uncertainty in manner determination and some represents cultural and regional differences in practice. The variation and uncertainty in these determinations has led some to suggest that this role be abandoned. However, the statistical, policy, and cultural need for these determinations dictate that the function will be performed even if abandoned by the medical examiner community. Medical examiners are uniquely positioned and trained to fill this need, and should continue to do so.

Car accidents as a method of suicide: a comprehensive overview

The research literature provides evidence on the possible link between single-car accident drivers and suicidal intent, and some scholars have stressed the role of unconscious suicidal motivations in some single-car accidents. This paper review relevant literature on the topic and sheds light on neglected factors that may play a central role in reducing the number of deaths due to car accidents. We performed careful PubMed, and PsycInfo searches to identify all papers and book chapters in English during the period 1955-2011. Our overview of the literature indicates that above 2% of the traffic accidents are suicide behaviors. However, the phenomenon may be underreported, considering that suicides by car accidents may be reported as accidental in the national statistics. On the other hand, the association between accident-pronesses and unconscious self-destructive impulses is an issue that is difficult to solve.

Motor vehicle accident or driver suicide? Identifying cases of failed driver suicide in the trauma setting

Many authors have suggested that some road traffic crashes are disguised suicide attempts. A case report and literature review is used to explore this claim and to examine the frequency and risk factors associated with driver suicide. The author concludes the methodological difficulty of establishing the driver's intent of suicide accounts for an under-estimation of the frequency of this event and that many cases of driver suicide go unrecognised. Familiarity with the risk factors associated with driver suicide may assist in the identification of cases of failed driver suicide and referral to psychiatric services.

Suicide by motor vehicle "accident" in Queensland

OBJECTIVE

Around the world, a substantial proportion of motor vehicle crash deaths are recognized as "hidden" suicides. This project sought to progress understandings of drivers who used a motor vehicle to die by suicide in Queensland, Australia, during the period 1990 to 2007.

METHODS

Data for this study were derived from the Queensland Suicide Register and forensic crash investigation case records. Analysis focused on life circumstances and events preceding the death, physical and mental illnesses, past suicidality, and indication of suicide intent (e.g., suicide notes or statements).

RESULTS

Compared to cases using other methods, confirmed driver suicides were more likely to be males aged between 25 and 44 years who were employed at the time of death. A large proportion of driver suicides had consumed alcohol immediately prior to the crash and experienced a number of life events, including relationship conflict, legal or criminal issues, and financial problems.

CONCLUSION

These exploratory results indicate the need to educate crash investigators about the characteristics of those who use a motor vehicle to die. Improving the information available on the mental and physical health and background life-related factors of crash victims can help coroners and researchers determine whether these deaths were intentional. Further investigation is needed in order to formulate intervention strategies for those who may be vulnerable to driver suicide.

At-fault motor vehicle crash risk in elderly patients treated with antidepressants

OBJECTIVE

To assess whether antidepressant treatment is associated with a temporary increase in the risk of a motor vehicle crash among older adults.

DESIGN

Population-based case-only time-to-event analysis.

SETTING AND SUBJECTS

Data from transportation and healthcare databases for adults age 65 and older in Ontario, Canada, between January 1, 2000, and October 31, 2007. Consecutive adults who had a motor vehicle crash anytime following their 66th birthday.

MEASUREMENTS

The primary exposure variable was treatment with antidepressant medication, and the primary outcome measure was a motor vehicle crash.

RESULTS

A total of 159,678 individuals had a crash during the study, of whom 7,393 (5%) received an antidepressant in the month prior to the crash. The hazard ratio (HR) of crash associated with second-generation antidepressants was 1.10 (95% confidence interval [CI]: 1.07-1.13, χ² = 41.77, df = 1, p <0.0001), adjusted for gender, license suspensions, and other medications, but the risk for first-generation antidepressants was not significant. The increased risk was restricted to those who were also concurrently prescribed a benzodiazepine (adjusted HR: 1.23, 95% CI: 1.17-1.28, χ² = 85.28, df = 1, p <0.0001) or a strong anticholinergic medication (adjusted HR: 1.63, 95% CI: 1.57-1.69, χ² = 627.31, df = 1, p <0.0001), and was confined to crashes where the patient was at fault. The increased risk was apparent for the first 3-4 months following initiation of an antidepressant and returned to baseline thereafter.

CONCLUSIONS

Prescriptions for second-generation antidepressants in older adults are associated with a modest increased risk of motor vehicle crashes, when combined with other medications that can impair cognition.

Does psychological distress increase the risk for motor vehicle crashes in young people? findings from the DRIVE study

PURPOSE

Earlier research demonstrates increased and decreased risk of crash related to psychological distress; however, previous literature has almost entirely used retrospective study designs and has not been able to adequately control for important confounders such as exposure to driving, alcohol and drug use, or having had a previous crash. This study aimed to assess the relationship between psychological distress and risk of motor vehicle crashes.

METHODS

The DRIVE study is a prospective cohort study of 20,822 novice drivers aged 17-24 years in Australia. Information on risk factors for motor vehicle crash was collected through online questionnaire and subsequently linked to police-reported crashes. Poisson regression was used to analyze risk of various crash types by low, moderate, high, and very high levels of psychological distress, taking into account other known risk factors for crash.

RESULTS

Compared to the referent group with low or no distress, a protective effect against crash was observed for young people who reported a moderate amount of psychological distress in unadjusted (RR = .87; 95% CI = .76-1.00) and multivariable analyses (RR = .85; 95% CI = .74-.97). Severe psychological distress was not significantly associated with an increase or decrease in the risk of crash. Psychological distress was not significantly associated with an increased risk of single vehicle crash.

CONCLUSION

Earlier studies may have overestimated risk for motor vehicle crashes associated with psychological distress. This study found little convincing evidence to support a strong risk relationship for higher levels of distress and indeed found a modest protective association for low levels of distress.

Self-harm and risk of motor vehicle crashes among young drivers: findings from the DRIVE Study

BACKGROUND

Some motor vehicle crashes, particularly single-vehicle crashes, may result from intentional self-harm. We conducted a prospective cohort study to assess the risk that intentional self-harm poses for motor vehicle crashes among young drivers.

METHODS

We prospectively linked survey data from newly licensed drivers aged 17-24 years to data on licensing attempts and police-reported motor vehicle crashes during the follow-up period. We investigated the role of recent engagement in self-harm on the risk of a crash. We took into account potential confounders, including number of hours of driving per week, psychological symptoms and substance abuse.

RESULTS

We included 18 871 drivers who participated in the DRIVE Study for whom data on self-harm and motor vehicle crashes were available. The mean follow-up was 2 years. Overall, 1495 drivers had 1 or more crashes during the follow-up period. A total of 871 drivers (4.6%) reported that they had engaged in self-harm in the year before the survey. These drivers were at significantly increased risk of a motor vehicle crash compared with drivers who reported no self-harm (relative risk [RR] 1.42, 95% confidence interval [CI] 1.15-1.76). The risk remained significant, even after adjustment for age, sex, average hours of driving per week, previous crash, psychological distress, duration of sleep, risky driving behaviour, substance use, remoteness of residence and socio-economic status (RR 1.37, 95% CI 1.09-1.72). Most of the drivers who reported self-harm and had a subsequent crash were involved in a multiple-vehicle crash (84.1% [74/88]).

INTERPRETATION

Engagement in self-harm behaviour was an independent risk factor for subsequent motor vehicle crash among young drivers, with most crashes involving multiple vehicles.

The impact of mental health symptoms on heavy goods vehicle drivers' performance

High levels of psychological distress in fulltime employees are prevalent (4.5% per month). Symptoms of impaired mental health include difficulties with attention, concentration, motivation, decision-making, visuo-motor control, and psychomotor reaction times. There is limited research on the impact these symptoms have on heavy goods vehicle (HGV) drivers' performance. In this study 1324 HGV drivers were surveyed using the Depression, Anxiety, Stress Scale (DASS) and the Health and Performance at Work Questionnaire (HPQ). Depression, anxiety and stress had little effect on driver absenteeism rates or self-rated driving performance. However, severe (1.5% of drivers) and very severe (1.8% of drivers) depression was associated with an increased odds ratio (OR=4.5 and 5.0, respectively) for being involved in an accident or near miss in the past 28 days. This odd ratio is akin to driving with a blood alcohol content of about 0.08%. Given the number of HGV vehicles and the prevalence of depression this equates to 10,950 HGV drivers with an increased statistical risk of an accident or near miss. As the impact of HGV accidents is potentially large, including loss of life, it would be sensible to extend the research findings here into an action plan.

Diseases, consumption of medicines and responsibility for a road crash: a case-control study

The role of medical conditions in crashes is a topic of public debate. Some studies suggest that there has been a reduction in road traffic crashes subsequent to the medical restrictions introduced on drivers with medical deficiencies. As in today's society the car is an important factor for independence and socialization, it seems important to consider whether diseases or consumption of drugs increase the risk of causing a road crash in comparison to well-known major crash risk factors. A case-control study was conducted (733 injured drivers). The cases were subjects who were partly or totally responsible for their crash. The 304 controls were the non-responsible drivers. Diseases and medicine consumption were analyzed using logistic regression models. Cases were characterized by a higher percentage of young men. They were more frequently affected by fatigue, as were subjects who had consumed alcohol. A higher risk in subjects suffering from hypertension is observed (adjusted odds ratio [adjOR]=3.82; 95%CI=[1.42-10.24]). An association between antidepressant consumption and responsibility appeared (adjOR=3.61; 95%CI=[1.30-10.03]).

CONCLUSION

Medical factors associated with responsibility were arterial hypertension and antidepressant consumption. Other medical conditions do not seem to play a preponderant role comparing to individual behaviours.