Should a Muslim Consult a Psychologist or Psychiatrist?
Question

I will tell you my problem in brief. I suffer from problems because of a domineering father, who throughout our lives was very strict with us. I also suffer from intrusive thoughts, social phobia, high sensitivity and many psychological problems. 
I decided to go to a psychologist, and this psychologist has studied psychology, but I was shocked by a fatwa that I read on your website (no. 99983 ) in which you do not regard it permissible to study psychology. 
So what should I do? Should I stop going to the psychologist, because he studied psychology? How can I treat myself then?
Praise be to Allah.We ask Allah, the Most Generous, to relieve your worry and distress, and grant you relief.
Is it permissible to study psychology?
In the answer to which you referred, there is nothing to suggest that there is no benefit in studying medicine or receiving treatment from a psychologist. Rather it is not allowed to study them if the teacher has little knowledge of Islamic teachings, and the university is one which mixes truth with falsehood, as is the case in the universities of Western countries. 
The prohibition on studying this specialty when it is like that, is so as to bar the means that may lead to confusion, misguidance and possibly disbelief.
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
“In principle, anything that may be a cause of confusion (and temptation) is not permissible, because any means that may lead to mischief must be blocked, unless there is some interest that could be served, which outweighs the possible mischief.” (Majmu‘ al-Fatawa, 15/419)
And he (may Allah have mercy on him) said: 
“This is a basic principle of Islamic teachings, as we stated when we discussed the principle of barring the means that may lead to evil and so on, and we explained that any action that may often lead to what is prohibited is to be regarded as a cause of evil and mischief, so if there is no shar‘i interest that could be served by it that would outweigh its mischief, and the mischief that it causes outweighs any interests that it could serve, then it is prohibited. In fact, any cause that could lead to corruption is to be forbidden, if there is no interest to be served by it that could outweigh its mischief. So how about a cause that often leads to corruption?” (Al-Fatawa al-Kubra, 4/465)
The one who studies this specialty and avoids its mischief, so that he follows Islamic guidelines when treating patients and does not prescribe any haram medicine, such as narcotics or tranquilizers, and does not advise patients to engage in any haram behaviour – in that case, there is no cause to prohibit it, and what this psychologist has to offer serves an interest that could outweigh anything questionable.
Does Islam forbid seeking medical treatment?
Islam does not forbid remedies and medications that will not lead to any bad consequences, because Islam only came to guide people to that which could serve their best interests in this world and the Hereafter.
Ibn al-Qayyim (may Allah have mercy on him) said:
“The basis and the aim of Islamic teachings is founded on wisdom and serving the best interests of people in this world and the Hereafter.” (I‘lam al-Muwaqqi‘in, 4/337)
If this doctor whom you are going to consult is trustworthy in terms of his religious commitment and specialty, and does not prescribe medicines or remedies except those that are permissible, there is nothing wrong with consulting him and benefitting from his treatment.
Shaykh ‘Abd al-‘Aziz ibn Baz (may Allah have mercy on him) was asked:
We have an older brother who was religiously committed in terms of prayer, fasting, doing ‘umrah, reading Quran, regularly offering prayer in congregation in the mosque and attending dhikr circles, but suddenly he changed and stopped praying, reading Quran and attending dhikr circles. He started to sit on his own in his room, and he doesn't even go to work. Please advise me what I should do to help my older brother. May Allah reward you with good.
He replied: 
“What is prescribed is to treat him with prophetic medicine and remedies and treatments known to specialist doctors that are not contrary to Islamic teachings, because the Prophet (blessings and peace of Allah be upon him) said: “Allah has not sent down any disease but He has sent down a remedy for it.” And he (blessings and peace of Allah be upon him) said: “For every disease there is a remedy, so if you find the right remedy for the disease, it will be healed by Allah’s leave.” (Narrated by Muslim in his Sahih)
And he (blessings and peace of Allah be upon him) said: “O slaves of Allah, treat sickness, but do not treat it with anything haram.” One of the Islamically-prescribed remedies is to have Quran and du’as recited over him by people of knowledge and faith, in the hope that Allah will benefit him thereby.
Another beneficial means of treating this and similar cases is taking him to specialist doctors who are people of faith and piety, in the hope that they will be able to find out the cause of his sickness and treat it. May Allah heal him from what has befallen him; may He help you to treat him in ways that will benefit him; and may Allah relieve him of his sickness, for He is Most Generous, Most Kind.” (Majmu‘ Fatawa ash-Shaykh Ibn Baz, 9/410)
Can Muslims consult a psychologist or psychiatrist?
There is no blame on you and no problem in continuing to seek treatment from the psychiatrist, if he is trustworthy in terms of his knowledge and religious commitment, and is skilled in his profession.
And Allah knows best.