Association Between Psychiatric Disorders and Age of Onset: A Pilot Cross-Sectional Study of 50 Cases

Background: Psychiatric disorders differ in their typical age of onset, but evidence describing onset patterns in small clinical samples from Kerala, India, is limited. This pilot study examined the association between diagnostic group and age of symptom onset and described the interval between symptom onset and first diagnosis. Methods: A cross-sectional observational study was conducted using 50 consecutively sampled patient records from psychiatric outpatient and inpatient services at VPSV Ayurveda College, Kottakkal, Kerala. Diagnoses were based on DSM-5 criteria. Data included age at symptom onset, age at first diagnosis, sex, source of onset information, family psychiatric history, comorbidity, and medical or neurological conditions. Descriptive statistics and non-parametric tests were used; inferential analyses were considered exploratory. Results: Participants included 30 males and 20 females; mean current age was 35.14 ± 15.36 years. Mean age at symptom onset was 26.02 ± 14.83 years (median 25.5; range 1-72), and 28% reported onset before age 18. Age of onset differed across ten diagnostic groups (Kruskal-Wallis H = 28.58, df = 9, p < 0.001). Median onset was earliest in neurodevelopmental disorders (3.5 years) and latest in neurocognitive disorders (66 years). Median onset-to-diagnosis interval was one year (interquartile range 0-4); 14% waited six years or longer. Earlier onset correlated with a longer interval to diagnosis (Spearman ? = -0.350, p = 0.013). No significant sex difference in onset age was observed. Conclusion: The findings suggest distinct onset patterns across diagnostic groups in this clinical sample and indicate that some patients experience prolonged diagnostic delays. Larger, multicentre studies are required to confirm these exploratory results.