Abstract

Objective

To compare the time trends of Google search interest in Ketamine online and criminal offenses related to this drug.

Methods

Google Trends data for the search term “meth” was compared to methamphetamine-related crime statistics (incl. use, possession, and dealing) in Switzerland, Germany, and Austria for the years 2004–2016. Google data was available monthly. Crime data was available yearly, and monthly values were imputed.

Results

On the country level, internet search trends for “meth” roughly paralleled relevant criminal activity. State-level data, which was available for Austria, showed more heterogeneity. Cross-correlations for yearly data almost always peaked at a lag time of 0 and coefficients were mostly between 0.7 and 1.0 on the country level, and between 0.5 to 1.0 on the state level. Monthly cross-correlations based on imputed values were substantially lower, ranging from 0 to 0.6.

Conclusions

These results encourage further evaluation by law enforcement authorities of Google search activity as a possible predictor of methamphetamine-related crime. However, several limitations, in particular the crude temporal resolution of available crime data, precluded a detailed assessment of the relationship between internet search trends and the development of methamphetamine-related crime in central Europe.

Introduction

Methamphetamine is a stimulant drug with strong abuse potential. It acts on the monoamine neurotransmitter system of the brain and increases extracellular concentrations of dopamine, norepinephrine, and serotonin. At higher doses, it produces feelings of euphoria, extreme wakefulness, rapid flow of ideas, feelings of increased capacity and energy, garrulousness, talkativeness, and intense sexual arousal. Methamphetamine can be ingested, smoked, snorted, dissolved in water or alcohol, and injected. It is sold as powder, crystals, or pressed into tablets. The crystalline form consists of methamphetamine hydrochloride and is known as “crystal meth” or just “crystal”.

Potential adverse effects include dependence, neurocognitive deficits, mental health problems, and cardiovascular, dental, dermatological, and sexual health problems. Chronic methamphetamine use may also result in structural and functional brain deficits. Several studies indicate that consumption is furthermore associated with violent, (sexual) risk and criminal behavior and methamphetamine use predict general recidivism among offenders.

Methamphetamine is one of the most popular illicit drugs in the world, especially in East and South-East Asia North America, and in the Czech Republic and Slovakia.

In the rest of Europe, methamphetamine use was relatively rare before 2008 but has since grown significantly leading to an increase of meth-related offenses as well as police response. In Germany, it is particularly the states bordering on the Czech Republic, Bavaria, and Saxony, which have seen the largest methamphetamine problem.

“Google Trends” is a web service offered by Google to track the popularity of terms entered in its search engine. It delivers data on the frequencies of search terms broken down by geographical location and time. The data are relativized to the total search volume for that term in the specified region at the specified time. Thus, the data are not absolute, but normalized numbers.

Research using Google Trends and other user-generated internet data has experienced a dramatic rise in recent years. Considerable work has focused on tracking acute diseases, the best-known example being Google Flu Trends (GFT), a service established by Google in 2008 to predict spatiotemporal patterns of influenza activity.

Another promising use of internet data is as a tool in behavioral medicine to survey health-related online behaviors that may yield actionable insights for policymakers. Such data is especially useful where traditional systems of surveillance are not available. For example, Ayers et al have demonstrated using Google search trends that the popularity of e-cigarettes surpassed that of other smoking alternatives or cessation devices at a time when academic interest was still focused on the latter.

Internet search data offers a unique set of advantages and challenges. It is big,