Hello and welcome to Healthcare Magic. Thanks for your query. Some persons suffering from depression may not respond adequately to the usual treatments and may be suffering from what is known as a treatment-resistent depression. Now. don t get alarmed by this term because it does not mean that there is no treatment. It means that these persons need to be evaluated properly for possible causes of poor treatment response. A few of these causes are medical problems like thyroid disorders, ongoing psychological stress, poor treatment compliance, etc. So, your mother needs a detailed assessment in order to plan further treatment strategies. Further treatment options include trying different combination of anti-depressants, augmenting the antidepressant with other psychiatric medication like an anti-psychotic or a mood-stabilizer, thyroxine supplementation, etc. Also, combining intensive psychological therapies (such as Cognitive Behavioural Therapy - CBT) with medication often gives good results. Acanthosis is a dermatological condition causing hyperpigmentation (blackening) of the skin. For this she needs to consult a dermatologist for further evaluation and treatment. Wish you all the best. Regards, Dr. Jonas Sundarakumar Consultant Psychiatrist