This is a prospective observational Phase Four post marketing surveillance study planned to evaluate the effectiveness and safety of long acting injectable paliperidone in patients with schizophrenia, schizoaffective disorder, and bipolar mania. The study will be conducted at the Psychiatry Outpatient Department of Government Mohan Kumaramangalam Medical College, Salem.

The primary aim is to assess real world clinical effectiveness of long acting injectable paliperidone. Specific objectives are to evaluate improvement in symptom severity, monitor side effect profile including extrapyramidal symptoms, metabolic changes and prolactin related problems, determine continuation rates and reasons for discontinuation, and compare outcomes across the three diagnostic groups.

Thirty adult patients aged between eighteen and sixty five years of either gender will be recruited by consecutive sampling. Eligible participants will have a confirmed diagnosis of schizophrenia, schizoaffective disorder, or bipolar mania as per ICD Eleven and will have received long acting injectable paliperidone for at least six weeks. Patients with bipolar depression, other primary psychotic disorders, comorbid substance use disorder except nicotine, or those receiving concurrent psychotropic medications will be excluded.

Clinical assessments will include Clinical Global Impression Severity and Improvement scales, Positive and Negative Syndrome Scale for schizophrenia and schizoaffective disorder, Young Mania Rating Scale for bipolar mania, Abnormal Involuntary Movement Scale, Simpson Angus Scale, and metabolic measures such as weight, body mass index, serum prolactin, and blood glucose. These will be recorded at baseline, six weeks, twelve weeks, six months, and twelve months.

The primary outcome is the proportion of patients achieving significant clinical improvement at twelve months. Secondary outcomes include reduction in symptom scores, occurrence of side effects, treatment continuation rates, and potential policy relevance for District Mental Health Programme. The study will follow all ethical standards, and informed consent will be obtained from all participants or their legally authorized representatives when required.