Abu Zayd Ahmed ibn Sahl Balkhi was a 9th-century Persian polymath. He was born in Shamistiyan, in the Khorasan province of Balkh. It is now in northern Afghanistan.
He wrote extensively on a wide range of topics but he is best remembered for his work in what is now known as psychoanalysis—Masalih al-Abdan wa al-Anfus (Sustenance for Body the and Soul).
Malik Badri, who translated ‘Sustenance for the Body and Soul’, described the bulk of his works as the bulk of his works as “more than sixty books and manuscripts, meticulously researching disciplines as varied in scope as geography, medicine, theology, politics, philosophy, poetry, literature, Arabic grammar, astrology, astronomy, mathematics, biography, ethics, sociology as well as others.”
Most of his works did not survive but ‘Sustenance for the Body and Soul’ is preserved in two copies held in the Ayasofya Library in Istanbul.
Abu Zayd al-Balkhi was the first to write about phobia, calling it Fazaa'.
The concepts of mental health and mental hygiene were introduced by Abu Zayd al-Balkhi, who often related them to spiritual health.
He was the first to differentiate between neurosis and psychosis and the first to classify neurotic disorders.
He classified neurosis into four emotional disorders: fear and anxiety; anger and aggression; sadness and depression; and obsession.
He further classified three types of depression: normal depression or sadness; endogenous depression originating from within the body; and reactive clinical depression originating from outside the body.
He pioneered cognitive therapy in order to treat each of these classified disorders.