I was wondering what are the diseases of the pineal gland and what role does the gland play for us?

Produces Melatonin: The pineal gland primarily produces melatonin which is the a neurohormonal substance secreted and responsible for maintaining the circadian rhythm of the organism. In our case it helps us keep a virtual 24hr internal clock going which synchronizes all other bodily functions. Pineal tumors ; cysts can cause melatonin derangements leading to depression, peptic ulcers, and sexual dysfunction.

Melatonin: Pineal gland produce melatonin, depression, peptic ulcers, and sexual dysfunction may be exacerbated by a deficiency of melatonin. Stress and dietary habits may lead to deficiencies of both serotonin and melatonin. Melatonin inhibits the release of cortisol via the release of vasotocin. Abnormal circadian rhythms of cortisol may occur in states of decreased melatonin.