A Google Trends-based approach for monitoring NSSI

Figures & data

Figure 1 Google Trends-based NSSI hit-search volume over the years (from 2004 to 2012).

Notes: NSSI hit-search volume over the years 2004–2012 (top), a map of Italian towns with higher flux volumes (bottom, left), and a list of the most searched NSSI-related terms (bottom, right).
Abbreviation: NSSI, non-suicidal self-injury.

Figure 2 Autocorrelation plot for the NSSI hit-search and partial autocorrelation plot, showing a regular cyclical pattern.

Abbreviations: ACF, autocorrelation function; NSSI, non-suicidal self-injury; PACF, Partial autocorrelation function.

Figure 3 Pearson’s correlation plots for some of the most important NSSI-related hit search terms.

Abbreviation: NSSI, non-suicidal self-injury.

Table 1 A list of the towns with higher normalized NSSI hit-search flux volumes

Towns with high hit search volumes	Normalized hit search volume (%)
Milan	100
Naples	96
Rome	94
Padua	86
Palermo	80
Turin	78

Abbreviation: NSSI, non-suicidal self-injury.

Table 2 Pearson’s correlation coefficients for different hit search volumes related to NSSI and their statistical significance according to their two-tailed P-value

NSSI-related hit search	Pearson’s correlation coefficient	P-value (two tails)
NSSI and suicide	r =0.26	P=0.00**
NSSI and blood	r =0.33	P=0.00**
NSSI and cutting	r =0.48	P=0.00**
NSSI and razor	r =0.52	P=0.00**
NSSI and depression	r =−0.60	P=0.00**
NSSI and anxiety	r =0.18	P=0.00**
NSSI and bullying	r =0.12	P=0.01*
NSSI and anorexia	r =−0.23	P=0.00**
NSSI and bulimia	r =−0.56	P=0.00**

Notes:

* Statistically significant, with P-value <0.05

** statistically significant, with P-value<0.01.

Abbreviation: NSSI, non-suicidal self-injury.