Neurological diseases often manifest with psychiatric symptoms, profoundly impacting patients' well-being and treatment outcomes. This comprehensive review examines the psychiatric manifestations associated stroke, epilepsy, Huntington's disease, amyotrophic lateral sclerosis (ALS), traumatic brain injury (TBI), and multiple system atrophy (MSA). Key psychiatric symptoms include agitation, depression, anxiety, apathy, hallucinations, impulsivity, and aggression across these diseases. In addition, ethical considerations in treating these symptoms are paramount, particularly regarding genetic testing implications, end-of-life discussions, informed consent, and equitable access to innovative treatments. Effective management necessitates interdisciplinary collaboration, personalized interventions, and a focus on patient autonomy. Understanding the psychiatric burden of neurological diseases is crucial for enhancing patients' quality of life. Further research is needed to elucidate underlying mechanisms and develop targeted interventions. This review underscores the importance of comprehensive assessment and ethical treatment practices to address psychiatric manifestations effectively.