Drugs and Wellbeing

Substance misuse is an important social issue, associated with a range of mental health problems (Moore et al. 2007) and antisocial behaviour and crime (Bennet and Holloway 2005; Bennet et al. 2008), in part to fund drug use itself (Bennet et al. 2008; Cross et al. 2001; Kopak et al. 2014).

Impact of Drugs on Wellbeing

A considerable body of research has suggested that use of drugs may lead to lower wellbeing and particularly to the development of depressive symptoms in later life following early consumption (e.g. Brook et al. 2002), but it is unclear whether this relationship is due to the drug itself or due to the circumstances surrounding its use. For instance Semple et al. (2005) argued that depressive symptoms associated with methamphetamine use are not merely due to negative life circumstances associated with drug use such as poorer employment, health and family, but can be directly attributed to the use of the drug itself. By contrast, using a sample of undergraduate students, Allen and Holder (2014), argued that it is the circumstances around the use of marijuana (e.g. poor attendance and academic performance), rather than the chemical substance itself, which is associated with poorer wellbeing. Although clearly an important issue for future study, this distinction is less relevant to the current research which focused mainly on an estimate of the costs of this loss on wellbeing rather than the complex causal pathways through which it might have operated. Moreover, some studies have found a positive relationship between drug use and wellbeing. It has been shown that marijuana legalization is associated with decreasing suicide rates, which may be partially the result of a decrease in alcohol consumption (Anderson et al. 2014).

Other Factors Playing a Role in the Drug–Wellbeing Relationship

Theoretical (Arnett 2005) and empirical contributions (Miller and Plant 2002) have pointed out the existence of other factors associated with substance use, suggesting for example that using drugs may be a strategy to cope with low levels of wellbeing. In a study on a sample of adolescent cannabis users, Miller and Plant distinguished between three different types of users. First, people using the drug for recreational purposes; second, those who used drugs within a wider context of anti-social delinquent behaviours; third, individuals that felt unsatisfied with how their life was going, using the drug for “self-medication”. Levy (2008) also theorised that individuals from low socioeconomic groups consuming drugs for self-medication may end up trapped in a “vicious circle” due to the negative effect of drugs on employment and social outcomes.

These results lead to some reflections. The first is that it is not surprising that drug use is more widespread among younger people, especially in the case of recreational drugs taken when together with friends. ONS (2016a) data, for example, shows that in England and Wales 18% of people aged 16–24 years have used drugs at least once in the last year, against 8.4% in the broader category of 16–59 years. The early twenties represents an age in which the control from parents starts weakening—especially in the case of students living away from home (see Bennet and Holloway 2015 for a comparison between students and non-students), that have not yet experienced that “turning point” in life (i.e. starting employment or starting a family) associated with a greater degree of social control that discourages delinquent behaviour in general (Corman et al. 2011; Walker et al. 2013). Levitt (1998) also showed that coming of age is associated with a sharp decrease in crime rates in general, this being higher the severer the punishments for adults are compared to those for youths. Along these lines, Arnett (2005) theorized that so-called “emerging adults” using drugs consider this a “behaviour that is acceptable at their current age but one that they will give up in the course of growing into adulthood” (p. 247).

Second, personality plays an important role in drug use. Arnett (2005) hypothesised that optimistic individuals are more likely to use drugs, as they tend to underestimate the harmful effect drugs can have on their life. Along these lines, Peretti-Watel (2006) found that cannabis users have higher scores of risk denial compared to non-users. In the study by Allen and Holder (2014) marijuana users tended to score higher in “Openness to experience” and lower in “Agreeableness” and “Conscientiousness”. This is consistent with the results by Tartaglia et al. (2017b). Allen and Holder (2014) also found that the negative social consequences of the drug are more severely felt by individuals high in “Neuroticism”.

The third reflection is about the issue of reverse causality in the drug-wellbeing link. Among the papers reviewed by Moore et al. (2007), one of the most appropriate and commonly used methods to deal with the problem appears to be using panel data and controlling for the presence of mental health problems at some point earlier in time. In our research, given the cross-sectional nature of the dataset used, we were not able to fully address this issue. In order to reduce the bias associated with it, we controlled for a number of personal characteristics, such as health status, employment condition and marital status, which could at least in part explain the endogeneity issue. We are also aware that there may be a reciprocal association between wellbeing and income with happier people tending to earn more, even some years later (De Neve and Oswald 2012), and higher income (even through lottery wins) associated with greater well-being (possibly after a lag period, Gardner and Oswald 2007). We attempted to account for this using an instrumental variable approach proposed by Fujiwara et al. (2014, see Section 4.3).

Alcohol Consumption and Wellbeing

In this paper we also controlled for the link between wellbeing and alcohol consumption, a theme which has been already analysed by part of the literature. Gil-Lacruz and Gil-Lacruz (2010) found evidence of a significant effect of drinking on the prescription of tranquilizers among Spanish adolescents, holding also when taking into account reverse causality issues. Baumberg Geiger and MacKerron (2016) analysed data from the British Cohort Study and found that heavy drinking is a significant predictor of lower wellbeing. A similar result is also reported by Dietze et al. (2013) in an analysis on a sample of injection drug users that found a significant negative effect of drinking on wellbeing, even controlling for type and intensity of drug use. On the other hand, other studies have suggested that drinking may be a way to cope with stress and anxiety (Lanier et al. 2001; Tartaglia et al. 2017a).

The Welfare Cost of Drug Use

The current research extends most previous work by going beyond exploring the association between drug use and wellbeing and attempting to also evaluate the cost of drug use using the “life satisfaction approach”. This relatively novel approach (presented in more detail in Sect. 4) draws upon the analysis of the relationship between life satisfaction and income to compute the equivalent value of a range of non-market goods (HMT 2011), such as social relationships (Powdthavee 2008; Orlowski and Wicker 2015) and marriage (Qary 2014). In the same way, it is used to calculate the equivalent amount of money that would be needed to compensate for the existence of problems, such as housing problems (Fujiwara 2013) and negative life events, such as experiencing unemployment (Powdthavee 2008) or the death of a family member (Oswald and Powdthavee 2008).

To the best of our knowledge, only Powdthavee and van den Berg (2011) have used the life satisfaction approach in the context of drug use, focusing in particular on alcohol and drug problems, along with a number of other health issues. In their paper, they used BHPS panel data and distinguished between a level and a shock effect of income and health problems, reflecting respectively how the average value of these variables, as well as their annual shift from the average, affects life satisfaction. Their results suggested that, overall, “relief from alcohol and drug related problems” is worth approximately £9 million a year/per person. Clearly this amount seems very high and thus the approach was further elaborated by Fujiwara (2013). Specifically, Fujiwara used an instrumental variable approach to deal with the endogeneity problem in the income-wellbeing relationship. Using an unbiased coefficient for income and drawing upon the health problems coefficients estimated by Powdthavee and van den Berg (2011), Fujiwara concluded that overcoming alcohol and drug problems is worth £24,000 a year/per person, a much lower, probably more realistic figure. The current research presents findings using both approaches for comparison (though of note unlike the BHPS there is no within-person variance over time in our cross-sectional data so we are not directly comparing like with like).

The life satisfaction approach measures the value of non-market goods and life events looking at how they impact subjective wellbeing, i.e. reflecting the point of view of the individual. A different perspective—looking mainly at the costs of drug use for the society—is instead the focus of another part of the literature (e.g. Lievens et al. 2017). Within this literature, the direct drugs-related health and crime expenditures imposed to the society are taken into account together with the indirect productivity losses and intangible quality of life losses. This approach was taken by the Drug Treatment Outcomes Research Study (DTORS). This study measured the benefits of treating drug problems using follow-up interviews on a sample of approximately 1800 individuals being treated in a structured setting in England (Davies et al. 2009; Donmall et al. 2009). DTORS took into account the benefits of the treatment in terms of health outcomes, as measured by Quality Adjusted Life Years (QALYs), and avoided costs for society from reduced criminal misconduct and lower access to public services to deal with health and social problems. Results suggested a total benefit per person of approximately £6500 a year, with a benefit-cost ratio of about 2.5:1. Given that this is a much broader impact assessment than that used by the life satisfaction approach it is interesting to see how much lower this figure is even compared to Fujiwara’s (2013) £24,000 a year/per person.

Contribution to the Literature

In sum, the current paper contributes to the existing literature by using data drawn from the Crime Survey for England and Wales to explore how reported use of drugs is related to life satisfaction and, following Powdthavee and van den Berg (2011) and Fujiwara (2013), attempted to value the individual cost associated to taking drugs, in terms of wellbeing loss. The current research distinguished between cannabis and other drugs and between current users, past users and never users. As far as we aware, this is novel and sheds light on the wellbeing costs of different types of drugs. Our analysis has been partly limited by the cross-sectional nature of the available data. In fact, we are not able to draw causal conclusions on the drug use-wellbeing relationship. Nevertheless, we have tried to address the reverse causality issue by including a number of socio-demographic covariates which are likely to play a role in this relationship, in order to partly mitigate the problem. Moreover, in dealing with the relationship between income and wellbeing, we have drawn upon the findings of previous studies, in an attempt to provide unbiased measures of the monetary cost of drug consumption. The computed figures were then used to extend our findings to compute the overall cost of taking drugs at the national level. Finally, along with the cost of drugs, the value of drinking alcohol was measured, as a function of drinking frequency.