Approximately 4% of the population has aphantasia, which is defined as impoverished, or absent, sensory mental imagery. Previous research suggests that people with aphantasia (aphants) may have a higher prevalence of mental health conditions and neurodivergence compared to the general population, but aphantasia presents a special challenge for diagnosis and treatment. Many mental health conditions are currently characterized by imagery-related symptomology (such as sensory flashbacks in post-traumatic stress disorder or negative body image in eating disorders), and the dominant therapeutic treatments rely heavily on imagery techniques. Thus far, little is known about how this impacts mental healthcare experiences in individuals with aphantasia. In the current study, we will use a mixed-methods (questionnaire, interview) approach to comprehensively investigate the effects of aphantasia on seeking diagnoses and treatments for mental illness. Quantitative analyses on the questionnaire data revealed that virtually all psychiatric disorders manifest with a lack of imagery-related symptomology in aphantasia compared to typical imagery controls; aphants report “lack of awareness or understanding of aphantasia” as a common factor in missed- or misdiagnosis by mental health professionals, although the prevalence of missed and misdiagnoses are no different from typical imagery controls; and aphants are very likely to report that therapies involving mental imagery, especially visual imagery in CBT, are ineffective in their mental health treatment compared to controls. A detailed summary of the quantitative results follows.