Although non-adherence is common across all branches of medicine, psychotic disorders pose additional challenges that increase its risk. Despite the importance of non-adherence, clinicians generally spend too little time on assessing and addressing adherence attitudes and behaviors. Importantly, how adherence is measured significantly impacts the findings, and the most frequently employed methods of asking patients or judging adherence indirectly based on efficacy or tolerability information have poor validity. Novel technologies are being developed that directly assess adherence and that can also be used to both provide real-time feedback to clinicians and serve as an intervention with patients.