Google Gemini:

There is no medical, biological, or genetic link between penis size and the onset or development of schizophrenia. The size of a person’s penis during or after puberty does not cause, trigger, or increase the risk of developing schizophrenia.

The onset of schizophrenia during puberty and early adulthood is driven by complex neurodevelopmental and genetic factors:

• Neurobiological Onset: Schizophrenia is primarily a neurodevelopmental condition involving disruptions in brain circuit connectivity, neurotransmitter regulation (particularly dopamine and glutamate), and structural changes in brain tissue.
• Pubertal Timing: Schizophrenia most frequently manifests between late adolescence and early adulthood (typically ages 16–25 for men). This timing coincides with synaptic pruning—a normal process where the brain rewires and streamlines neural connections during puberty. In individuals genetically predisposed to schizophrenia, abnormal or excessive pruning during this stage of brain maturation triggers the onset of symptoms.
• Hormonal Changes vs. Physical Anatomy: While the hormonal surge of puberty (such as increased testosterone) influences both brain maturation and secondary sexual characteristics, physical anatomical traits like penis size are determined by individual genetic inheritance and androgen receptor responsiveness. They do not influence brain wiring or psychiatric vulnerabilities.

Picturing the urban myth. Girls, this is not how it always looks:

Any impression that men with schizophrenia have larger penises is purely a myth, likely reinforced by confirmation bias, urban legends, or confusion surrounding drug-induced priapism. Physical anatomical size has no role in triggering psychiatric disorders.