“…Of the thirty-one mental health-related papers reviewed (see Table 8), thirteen involved the use of Reddit data [15][16][17][18][19][20][21][22][23][24][25][26][27], ten used Twitter data [18,24,[58][59][60][61][62][63][64][65], one used Instagram [18], three used Facebook [8,18,67], six used OHC data [70][71][72][73][74][75], and one used data derived from Weibo [76], with twenty-two of the papers utilising supervised machine learning methods [8, 16, 18, 20-22, 24, 25, 58-62, 65, 67, 70-76], and twelve papers utilising unsupervised machine learning [8, 15, 18-22, 27, 59, 60, 70, 72]. The majority of the papers reported on the use of classical machine learning approaches [8, 15, 16, 18-20, 22, 24, 25, 27, 58-62, 65, 67, 71, 73-76], with a minority using modern machine learning methods [18,21,22,67,70,72]. Four of the mental health papers reviewed utilised primarily lexicon...…”