Onset by age:

• Three-quarters of persons with schizophrenia develop the disease between 16 and 25 years of age.
• Occurence after age 30 is uncommon.
• Occurence after age 40 is rare.

Onset by sex:

• In the 16-20 year old age group, schizophrenia affects more men than women.
• In the 25-30 year old age group, the incidence is higher in women than in men.

Early warning signs:

• Thought patterns become illogical.
• The sense of body boundaries deteriorates.
• The person experiences auditory hallucinations.
• Emotions become grossly inappropriate or flattened.
• The person feels that his/her thoughts are controlled by others, are not his own at all, or that he can control the thoughts of others.