A lot of contemporary people use to accuse muhammad of being possessed according to the quran. [1,2,3,4] Could there be any truth to their claims, or were they simply the first proud generation of islamophobes? Let’s look at the facts recorded by the muslim sources and find out for ourselves!
1. Muhammad’s childhood experience
When Muhammad was a child he was nursed by a Bedouin woman. During this time he had an experience with “two men in white raiment”. Here is W. M. Watt’s translation of Ibn Ishaq’s biography of Muhammad, page 36:
“…two men in white clothes came to me with a golden basin full of snow. They took me and split open my body, then they took my heart and split it open and took out from it a black clot which they flung away. Then they washed my heart and my body with that snow until they made them pure.” 
This event deeply disturbed the Bedouins and they returned Muhammad to his mother. Here is the story told by Muhammad’s wet-nurse, related in Guillaume’s translation of Ibn Ishaq, page 72:
“His [Muhammad’s friend’s] father said to me, “I am afraid that this child has had a stroke, so take him back to his family before the result appears. ….. She [Muhammad’s mother] asked me what happened and gave me no peace until I told her. When she asked if I feared a demon had possessed him, I replied that I did.” 
Conclusion: Muhammad’s wet-nurse thought that muhammad had become possessed by a demon.
2. Muhammad’s call to “prophethood”
A being described as the angel Gabriel by muhammad, finds muhammad in a cave worshipping allah, and decides to strangle him and exhorts him to recite. Muhammad, tries to no avail to explain to this being that he can’t read. After the third time strangling the muhammad, muhammad finally starts to recite something, and the angelic being releases him. 
After this encounter, muhammad shakes with fear, runs to his wife for refuge, screaming “cover me! cover me!”. Sound like a prophetic experience to you? Or does it sound like a demonic experience? You be the judge.
3. Muhammad himself thought he was possessed
From Guillaume’s translation of Ibn Ishaq’s famous early biography of Muhammad, sirat-rasul, we read:
So I [Muhammad] read it, and he [Gabriel] departed from me. And I awoke from my sleep, and it was as though these words were written on my heart… Now none of God’s creatures was more hateful to me than an [ecstatic] poet or a man possessed: I could not even look at them. I thought, “Woe is me poet or possessed – Never shall Quraysh [Muhammad’s tribe and kinsman] say this of me! I will go to the top of the mountain and throw myself down that I may kill myself and gain rest.” So I went forth to do so and then when I was midway on the mountain, I heard a voice from heaven saying “O Muhammad! thou are the apostle of God and I am Gabriel.”
The reference to “poet or possessed” comes from the notion that Arabs contemporary with Muhammad believed that poets created their poetry under the inspiration of demons. At-Tabari, one of Islam’s most highly respected early historians says, “The pre-Islamic Arabs believed in the demon of poetry, and they thought that a great poet was directly inspired by demons…” 
So by this time, Muhammad is trying to commit suicide by throwing himself down from a cliff, totally convinced that he is possessed!
4. Muhammad became suicidal big time
The visitations from the spirit continued. Then they stopped for a time believed to have been 6 months to 3 years. When this happened, Tabari, volume 6, page 76, records:
“The inspiration ceased to come to the messenger of God for a while, and he was deeply grieved. He began to go to the tops of mountain crags, in order to fling himself from them; but every time he reached the summit of a mountain, Gabriel appeared to him and said to him, “You are the Prophet of God.” Thereupon his anxiety would subside and he would come back to himself. 
5. His own tribe thinks he is possessed
Narrated Jundab bin ‘Abdullah :
Gabriel did not come to the Prophet (for some time) and so one of the Quraish women said, “His Satan has deserted him.” So came the Divine Revelation: “By the forenoon And by the night When it is still! Your Lord (O Muhammad) has neither Forsaken you Nor hated you.” Bukhari Book 2 Volume 21 Hadith 225
His own people from his own tribe now thinks he is possessed.
6. People around Muhammad thought he was possessed
Narrated Jundub bin Sufyan:
Once Allah’s Apostle became sick and could not offer his night prayer (Tahajjud) for two or three nights. Then a lady (the wife of Abu Lahab) came and said, “O Muhammad! I think that your Satan has forsaken you, for I have not seen him with you for two or three nights!” On that Allah revealed: ‘By the fore-noon, and by the night when it darkens, your Lord (O Muhammad) has neither forsaken you, nor hated you.’ (93.1-3) (Sahih Al-Bukhari, Volume 6, Book 60, Number 475)
1. His nurse thought muhammad was possessed
2. His call to prophethood seems demonic
3. Muhammad himself thought he had become possessed
4. Muhammad became suicidal and unstable as a result of his “revelations”
5. People around muhammad, and of his own tribe thought he had become demon-possessed
6. People in the quran thought that he was demon-possessed
Islam is false. Allah is a fabricated god made up by a false prophet.
 And the unjust said, “That you are following but bewitched man!” Sura 25:8
 They said, “Surely you are only from the bewitched! Sura 26:153
 Then they turned away from him, and they said, “A demon-possessed teacher.” Sura 44:14
 And they say, “Are we forsaking our gods to a demon-possessed poet?” Sura 37:36
 “Muhammad at Mecca”, by W.M. Watt, Pub. Oxford University Press.
 “The Life of Muhammad”, by A. Guillaume, Oxford University Press.
 Bukhari Book 9 Volume 87 Hadith 111
 At-Tabari Vol. 9, page 167, note 1151
 “The History of al-Tabari”, translated by W.M. Watt, pub. by SUNY