Hello, The psychiatric symptom of suspicious may be present in depression, but suspicious may also be seen in host of other medical and psychiatric disorders. Hence a comprehensive assessment is required to understand her illness and plan a management. Hence please take your mother to a psychiatrist near you for comprehensive assessment and treatment. A psychiatrist may be able to make her understand need for medication. Else hospitalization, or use of once a month or fortnight injectable medication can be considered. Hence the first step for you will be to consult a psychiatrist near you. Hope this helps you. Best wishes for your health and future. Regards Delhi Mind Clinic