Vaping nicotine can increase anxiety symptoms and stress levels.
Holliday E, Gould TJ. Nicotine, adolescence, and stress: A review of how stress can modulate the negative consequences of adolescent nicotine abuse. Neurosci Biobehav Rev. 2016;65:173-184. doi:10.1016/j.neubiorev.2016.04.003 (note: the studies cited in the article below were all conducted in rats/mice)
Kassel JD, Unrod M. Smoking, anxiety, and attention: support for the role of nicotine in attentionally mediated anxiolysis. J Abnorm Psychol. 2000 Feb;109(1):161-6. doi: 10.1037//0021-843x.109.1.161. PMID: 10740949.
Morel C, et al. Nicotinic receptors mediate stress-nicotine detrimental interplay via dopamine cells’ activity. Mol Psychiatry 23, 1597–1605 (2018). https://doi.org/10.1038/mp.2017.145 (note: this study was performed on mice)
Wills TA, Sandy JM, Yaeger AM. Stress and smoking in adolescence: a test of directional hypotheses. Health Psychol. 2002 Mar;21(2):122-30. PMID: 11950102. (Commentary)