Ans. is 'b' i.e., Depression o Depressed mood, decreased appetite and no interest since one year suggest the diagnosis of depression,o For diagnosis of dysthymia, depressive symptoms should be present for at least 2 years.Mood disorderso According to ICD-10, mood (affective) disorders are grouped into six main categories.1) Manic episode: - Single episode of mania (not recurrent).2) Depressive episode : - Single episode of depression.3) Bipolar mood (affective) disorders : - Recurrent episodes of mania alone or recurrent episodes of mania & depression in the same patient at different times.4) Recurrent depressive disorder : - Recurrent (two or more) depressive episodes.5) Persistent mood disorder : - Persistent mood symptoms which last for more than 2 years (1 year in children & adolescents). Example are dysthemia & cyclothymia.6) Other mood disorders : - Mixed episodes, i.e., picture of depression and mania is present at the same time intermixed (in contrast to bipolar disorders where depression and mania occur at different time). It also includes rapid cycling - picture of mania and depression alternates rapidly with each other without a normal intervening period (in contrast to bipolar disorder where normal intervening is present between two episodes).