The most common comorbid illness with depression is: (A) Anxiety disorder, (B) Substance use disorder, (C) Obsessive-compulsive disorder, (D) Comorbid illnesses are rare
Answer is B. Substance use disorder is the commonest comorbid psychiatric illness. The other impoant ones are panic disorder, social anxiety and OCD. Substance use is more common in men depressives and anxiety in women depressives. Bipolar disorder patients have twice the rates of prevalence, in comparison to the unipolar depressive patients.