Related by context. Frequent words. (Click for all words.) 53 sleeplessness 50 sleepiness 50 sleep 50 physical exertion 48 interrogation techniques 47 insomnia 47 waterboarding 47 torture 46 sleep deprived 46 interrogations 46 hallucinations 46 boredom 46 sleep disturbances 46 tiredness 46 drowsiness 45 disorientation 45 simulated drowning 45 electric shocks 44 physiological 44 temperature extremes 44 overeating 44 interrogation technique 44 stress hormones 43 snoring 43 psychological trauma 43 sleep disorders 43 phobias 42 interrogation tactics 42 irritability 42 naps 42 exhaustion 42 stressors 41 binge eating 41 mood swings 41 jet lag 41 involuntary 41 circadian rhythms 41 beatings 41 fatigue 41 enhanced interrogation techniques 40 Waterboarding 40 depression anxiety 40 jetlag 40 caloric intake 40 dehydration 40 migraines 40 arousal 40 relaxation techniques 40 hypoxia 39 caffeine 39 tortures 39 strenuous exercise 39 harsh interrogations 39 sunburn 39 hypnosis 39 depression 39 interrogators 39 Dehydration 39 sunburns 39 cravings 39 degrading treatment 39 claustrophobia 39 solitary confinement 39 interrogation 39 loud noises 39 circadian rhythm 39 psychological 39 falling asleep 39 vomiting 39 sleeping 38 obsessive compulsive disorder 38 serotonin 38 hormonal 38 stressful situations 38 suffocation 38 sleep apnea 38 psychotropic drugs 38 stress 38 cognitive 38 acid reflux 38 psychological distress 37 simulates drowning 37 epileptic seizures 37 mental 37 loneliness 37 exertion 37 bingeing 37 anti depressants 37 body aches 37 false confessions 37 harsh interrogation techniques 37 melatonin 37 deafness 37 tinnitus 37 physiologically 37 behaviors 37 cortisol 37 strobe lights 37 awake 37 sedentary lifestyle 37 psychologists