planning to do my MSc thesis on identifying the psychiatric morbidity (depression, anxiety and body imagae/self esteem) in beta thalassemia major patients in Pakistan... I want to test if the thalassemics suffer more with such problems than the healthy people with same ages. Kindly suggest what study design should be employed? I thought of the case control but m not able to justify that. or should i go for the cross sectional study (identifying prevalance and associated factors for these variables in beta thalassemia patients)...kindly also guide me that which instruments should i use for the said variables (anxiety, depression and body image/self esteem) and how can i get the scales as i found that these must either be bought or requested from authors.