A space occupying lesion such as a brain tumour is unlikely as his symptoms are long standing. Gollum's diet is extremely limited, consisting only of raw fish. Vitamin B-12 deficiency may cause irritability, delusions, and paranoia. His reduced appetite and loss of hair and weight may be associated with iron deficiency anaemia. He is hypervigilant and does not seem to need much sleep. This, accompanied by his bulging eyes and weight loss, suggests hyperthyroidism. Gollum's dislike of sunlight may be due to the photosensitivity of porphyria. Attacks may be induced by starvation and accompanied by paranoid psychosis.