## 4 Discussion  
Greece has one of the lowest suicide rates among European countries, without increasing trends until 2010 [21]. Financial crisis resulted in a dramatic and unprecedented deterioration of the socio-economic conditions in the country. In such a socio-economic context, the suicide SDR recorded an increase by 50.1% from 2010 until 2014, and thereafter, a reduction by 13.8% until 2016. A systematic review of the association between unemployment and suicide found that unemployment might increase the risk of suicide by 250% within the first five years [22]. The same review found that even after 12-15 years, the suicide rate remained elevated by about 20%. Other studies have shown that suicide rates tend to return to previous levels after an economic crisis [23].  
The study findings showed a significant variation in suicide rates among regions, with a gap of 93% between the highest and lowest SDR values. In most countries, the gap in regional differences does not exceed 50-65% [24; 25; 26; 27]. The magnitude of the differences observed in Greece and the fact that they already existed before the crisis, raises questions about the factors resulting in that variation, which are discussed below. It is the first time that these large differences in the regional suicide rates in Greece have been reported. Exploring the literature, several epidemiological factors have been identified that may explain variation in suicidality. Cultural, religious, genetic, socio-economic factors as well as mental morbidity have been identified as main determinants [8; 9; 10; 11; 28]. Considering that religious factors have small variation in Greece, we should explore whether differences are driven by cultural, socio-economic, genetic, or mental factors. However, specific correlation analyses focusing on the pre-crisis period did not find any association of suicide rates with any single socio-economic or mental disorder mortality variable, except unemployment (\(p<0.05\)). In addition, the only regression model that showed a statistically significant effect was the one including as independent variables the \"change in per capita GTP\", \"per capita DHI\", and \"unemployment\". No other model was able to provide explanatory results during the pre-crisis period. These findings turn our attention to cultural along with geophysical factors such as insularity, which has been associated with elevated rates of suicidality [29]. The investigation of these factors was out of the scope of our study. The mental health-related factors are discussed below. Focusing on the financial crisis effects, we found only one study providing findings about the crisis impact on regional variation in suicide from Spain, which found a maximum gap between regions of about 55-65% [27]. Another study exploring the crisis effects on the variation between seven Spanish cities reported elevated suicide rates associated with crisis in three cities, and no effect in four cities [30]. There is evidence from previous research [31] that social and economic transition may not be uniform, with some regions affected much more than others. In our study, the coefficient of variance and the max/min SDR ratio were calculated at similar levels in the exposed and non-exposed period, indicating that crisis did not further widen overall regional inequalities. Similar findings were reported by [PERSON] et al. in Spain [27]. [PERSON] et al., who explored suicide variability among European cities and metropolitan areas during crisis, also found that area inequalities in suicide mortality did not change significantly after the onset of the crisis in Europe [32]. The differences observed among the various studies may be due to differences in their scope, methods, and limitations, or they may express real differences in the effects that economic crisis may have in the various countries.