A newly identified epigenetic hotspot for schizophrenia and bipolar disorder may give scientists a fresh path forward for devising more effective treatments and biomarker-based screening strategies. More than 100 million people worldwide have either schizophrenia or bipolar disorder, which are characterized by periods of hallucinations, delusions and irregular thought processes. They are both associated with overproduction of the neurotransmitter dopamine, a key regulator of reward-seeking behavior, emotional responses, learning and movement, among other functions.