Background: Developmental stuttering is associated with increased risk of psychological distress and mental health difficulties. Less is known about the impact of other developmental speech problems on psychological outcomes, or the impact of stuttering and speech problems once other predictors have been adjusted for. Aims: To determine the impact of parent-reported adolescent stuttering and other speech difficulties on psycho- logical distress and associated symptoms as measured by the Rutter Malaise Inventory. Method & Procedures: A British birth cohort dataset provided information about 217 cohort members who stuttered and 301 cohort members who had other kinds of speech problem at age 16 according to parental report, and 15,694 cohort members who had experienced neither stuttering nor other speech difficulties. The main analyses concerned associations between adolescent stuttering or speech difficulty and score on the Rutter Malaise Inventory at age 42. Other factors that had previously been shown to be associated with score on the Malaise Inventory were also included in the analyses. Outcomes & Results: In the adjusted analyses that controlled for other predictors, cohort members who were reported to stutter had higher malaise scores than controls overall, indicating a higher level of psychological distress, but they were not at significantly more likely to have malaise scores in the range indicating a risk of serious mental health difficulties. Cohort members who were reported to have other speech difficulties during adolescence had malaise scores that overall did not differ significantly from those of controls in the adjusted analyses, but they were at significantly greater risk of serious mental health difficulties. Conclusions & Implications: These findings support those of other studies that indicate an association between stuttering and psychological distress. This study is the first to have shown that adolescents who experience speech difficulties other than stuttering are more likely than controls to be at risk of poorer mental health in adulthood. The results suggest a need for therapeutic provision to address psychosocial issues for both stuttering and other developmental speech disorders in adulthood, as well as further research into the consequences in adulthood of stuttering and other developmental speech disorders. (Contains 4 tables and 1 figure.)