Table 4.
Studies of neurological and psychological effects of WP smoking in adolescents and young adults
| Authors Year | Study design | Study participant characteristics | Exposure measures | Outcomes of interest | Key results | Methodological information |
|---|---|---|---|---|---|---|
| Marsden et al.79 2019 | Cohort | N=5236 (out of 5482) smokers (N=885 smoked WP); 18–29 years; 36.7% male; 37.3% non-Hispanic white, 30.9% Hispanic, 16.8% Asian, 7.5% Black, 7.5% others; Texas, US | WP smoking; WP frequency | Psychological – depression (CES-D-10) | RR is 1.03 (1.01–1.05) for a 1-unit rise in scaled unit of frequency of WP smoking; RR is 1.04 (1.01–1.06) and 1.09 (1.04–1.15) for 5-day and 15-day of use within last 30 days, respectively. | Large sample of college students from multiple recruitment waves with repeated measurements; information collected at 6-month intervals; adjustments for age, ethnicity, sex, educational level, father’s education and wave number. |
| Ahmadian et al.84 2017 | Cross-sectional | N=20 (10 WPS, 10 C) age >20 years (27.6±3.1 for WPS, 26.1±3.6 for C); 100% sedentary male; Aliabad Katoul, Iran | WP Smoking | Cognitive function – number recall within 30 s Wingate supramaximal exercise test | No significant difference observed between WPS and C pre- and post-exercise. | Self-reported exposure to WP; participant selection process unspecified, no control for confounding. |
| Alomari et al.87 2018 | Cross-sectional | N=483 (195 WPS, 288 C); 14.4±1.1 years; 45.3% male; Irbid, Jordan | WP smoking | Neurological – biomarker (brain-derived neurotrophic factor – BDNF) | WP smoking associated with reduced circulating BDNF | Self-reported exposure; multi-stage random cluster sampling; controlled for BMI, age, gender and location in analysis; individuals self-reporting hyperlipidemia, hypercholesterolemia, hypertension, cardiac condition, hyperglycemia, psychiatric and stress-related mood disorders were excluded. |
| Bandiera et al.78 2016 | Cross-sectional | N=5438 students from 24 metropolitan colleges; 18–29 years; 63.8% female; 36.3% non-Hispanic white, 31.3% Hispanic, 16.9% Asian, 8.1 non-Hispanic Black, 7.5% Other; Texas | WP smoking | Psychological – depression (CES-D-10) | RR for depressive symptoms is 1.01 (0.85–1.19) for WPS use. | Self-reported exposure to WP; not clear if WP smokers were not multi-product users; large sample of college students from multiple colleges; adjustments for age, ethnicity, gender, college type. |
| Goodwin et al.81 2014 | Cross-sectional | N=1799 college students; 20.1±1.5 years for WPS, 19.8±1.4 for C; 58.8% female; Northeastern US | WP smoking | Psychological – mental health (self-reported diagnosis/treatment by a physician), perceived stress (self-reported level) | No association with mental health problems; no association with perceived stress. | Self-reported exposure; adjustments for age, gender, sorority status. |
| Heinz et al.82 2013 | Cross-sectional | N=143 (48% ever WPS); 19.26±3.42 years; 24% male; 36% Caucasian, 7% African American, 19% Hispanic, 33% Asian, 5% Other; Chicago, US | WP smoking, WP frequency | Psychological (depression) – Inventory to Diagnose Depression | No difference in depression symptomatology by WP use. | Self-reported exposure; convenience sample; lack of control for confounders. |
| King et al.83 2018 | Cross-sectional | N=2370; 21.1±0.4 years; 35.9% male; 83.2% White, 16.8% Non-White; Colleges in VA and NC, US | WP smoking, WP frequency | Psychological – self-reported mental health conditions (depression, anxiety, ADHD), stress (Cohen’s 10-item Perceived Stress Scale), depression (CES-D Short Form) | OR (CI) for WP use – 1.04 (1.01–1.06) per increase on Stress Scale Score, 1.03 (1.00–1.07) per increase on Depression Scale Score, no association with mental health diagnosis. | Self-reported WP smoking and mental health diagnoses; survey of college students, controlled for age, sex, race, ethnicity, and mother's education and cigarette smoking. |
| Meo et al.86 2017 | Cross-sectional | N=65 (33 WPS, 32 C); 24.45±2.93 years for WPS, 23.32±2.68 years for C); 100% male; Riyadh, Saudi Arabia | WP smoking | Neurological – cognitive function (Cambridge Neuropsychological Automated Battery – CANTAB) | WPS < C for attention switching task (AST) latency, AST congruent, AST incongruent, mean choice reaction time (CRT), CRT%. | Self-reported exposure to WP; groups matched based on age, gender, ethnicity, weight, height, SES, education level; excluded based on chronic morbidity, substance use and cigarette smoking; convenience sample with groups apparently from different populations; WPS not exclusively WP smoking. |
| Primack et al.80 2013 | Cross-sectional | N=100891; about 92% 18–26 years; 65.7% male; 70.2% White, 4.8% Black, 6.1% Hispanic, 9.7% Asian, 9.2% Other; Colleges in US | WP smoking, WP frequency | Psychological – self-reported mental health conditions (depression, anxiety, sleep disorder, ADHD, addictive disorder, stress) | OR (CI) for WP use – 1.4 (1.3–1.5) if depressed, 1.1 (1.0–1.2) if stressed. | Self-reported WP smoking and mental health diagnoses; large national survey; controlled for gender, sexual orientation, undergraduate status, race, relationship status, region, population size, and clustering by school. |
| Saadat et al.85 2018 | Pre-post | N=22 (WPS and CS – numbers not noted); 18–22 years (mean: 21.4±0.8); 100% male; Tehran, Iran | WP smoking session | Cognitive – psychomotor driving test | Two-hand coordination total mean duration score, but no other score, improved after WP smoking. | Controlled WP smoking session; convenience sample; controlled for order of test; objectively determined and controlled for nicotine dependence. |
*WPS: waterpipe smokers. CS: cigarette smokers. C: control.