Religious rituals is a behavioural pattern.
It occurs in an individual
It causes distress or disability
It is not expected as a part of a normal (secular) culture.
By your conclusion, catholics suffer from mental disorders.
Then again, you dishonestly quote-mined what the article actually said.
"Mental disorder or mental illness is a psychological or behavioral pattern that occurs in an individual and is thought to cause distress or disability that is not expected as part of normal development or culture. The recognition and understanding of mental disorders have changed over time and across cultures. Definitions, assessments, and classifications of mental disorders can vary, but guideline criteria listed in the ICD, DSM and other manuals are widely accepted by mental health professionals. Categories of diagnoses in these schemes may include dissociative disorders, mood disorders, anxiety disorders, psychotic disorders, eating disorders, developmental disorders, personality disorders, and many other categories. In many cases there is no single accepted or consistent cause of mental disorders, although they are often explained in terms of a diathesis-stress model and biopsychosocial model. "
Makes alot more sense with all the relevant points doesnt it?