International statistical classification of diseases and related health problems Mental illness 99 Classification 68 Diagnosis 47 Delusions 32 Schizophrenics 28 Schizophrenia 25 Psychoses 22 Nosology 16 Catatonia 14 Paranoia 9 Depression, Mental 8 Anxiety disorders 7 Manic-depressive illness 7 Manic-depressive persons 7 Autism spectrum disorders 6 Autism in children 5 Autistic children 5 Erotomania 5 Drug addicts 4 Echolalia 4 Hypomania 4 Marijuana abuse 4 Megalomania 4 Post-traumatic stress disorder 4 Somatoform disorders 4 Thought insertion 4 Conversion disorder 3 Depressed persons 3 People with bipolar disorder 3