There is increased mental-health adversity among individuals with autism spectrum disorder. At the same time, sexual and gender minority groups experience poorer mental-health when compared to heteronormative populations. Recent research suggests that autistic individuals report increased non-heterosexuality and gender-dysphoric traits. The current study aimed to investigate whether as membership of minority grouping becomes increasingly narrowed, mental health worsened. The present study compared the rates of depression, anxiety, and stress using the DASS-21 and Personal Well-Being using the personal well-being index between 261 typically-developing individuals and 309 autistic individuals. As membership to a minority group became more restrictive, mental health symptoms worsened (p < 0.01), suggesting stressors added. Specialized care is recommended for this vulnerable cohort.