Mental illness refers to a wide range of mental health conditions — disorders that affect your mood, thinking and behavior.
Examplesof mental illness include depression, anxiety disorders, schizophrenia, eating disorders and addictive behaviors. Although the exact cause of most mental illnesses is not known, it is becoming clear through research that many of these conditions are caused by a combination of genetic, biological, psychological, and environmental factors. Many people have mental health concerns from time to time. But a mental health concern becomes a mental illness when ongoing signs and symptoms cause frequent stress and affect your ability to function.
A mental illness can make you miserable and can cause problems in your daily life, such as at work or in relationships. In most cases, symptoms can be managed with a combination of medications and counseling (psychotherapy). 
Mental illness is any disease or condition that influences the way a person thinks, feels, behaves, and/or relates to others and to his or her surroundings. Although the symptoms of mental illness can range from mild to severe and are different depending on the type of mental illness, a person with an untreated mental illness often is unable to cope with life's daily routines and demands.
Islamically Mental Illness can also be caused by Magic or Jinn, which includes evil eye. The Prophet (ﷺ) that “The Shaytan flows through the son of Adam like blood.” Sahih al-Bukhari 3281 and 7171 This proves hades that Jinn can disturb you and hence can cause Illness. Ibn 'Abbas(R) reported Allah's Messenger (ﷺ) as saying: “The influence of an evil eye is a fact. Sahih Muslim 2187 (Book 26, 5426). One can get illness by evil eye.   
First of all, one should know that Islam considers all diseases including psychiatric illness as trials and tests from Allah. So, when any disease befalls a Muslim, it can be an expiation for his/her sins.As for the psychiatric diseases, some of them are caused by the lack of Eemaan (right creed) or physical and mental problems or both. The spread of these diseases nowadays is due to lack of Eemaan and spread of sins.
The ability to reason is a sign of maturity. So, as long as the person has this ability, then he is held responsible for anything he says or does. The Prophet (ﷺ) said: “The pen is lifted (stopped from writing the deeds) from three: the sleeping person until he wakes up, the handicapped or insane person till he becomes able to reason and the child till he grows up (reaches the age of puberty)”. Sunan Ibn Majah Book 10, Hadith 2120, Tirmidhi Jami` at-Tirmidhi 1423,Sheikh Al-Arna’ut said ‘this Hadith is sound because of the various good narrations of it’.
On the other hand, the psychiatric diseases like any other diseases should be treated. The Prophet (ﷺ) said: “Indeed, when Allah created the disease, He created its cure”. [Ahmad]The best remedy for such disease is in reciting the Qur'an. Allah Says: And We send down from the Qur'ân that which is a healing and a mercy to those who believe (in Islâmic Monotheism and act on it), and it increases the Zâlimûn (polytheists and wrong-doers) nothing but loss.} Quran Surah Isra17:82. One can also seek legal Ruqiya as it is a good remedy for such diseases. Moreover, making Du’a while in the state of Sujud (prostration) is a good remedy.
Probably the most important cause of the wide spread of these diseases is the weakness of the Eemaan (right creed) of most people and their weak belief in the predestination or Taqdeer. This leads them to being pessimistic (negative) and unable to accept their fate. Also, the greediness then keenness of people to get as much of the Duniya (world) comfort as they can, just to please themselves and satisfy desires, is a very important cause.
But some of these diseases are caused by chemical imbalances. In this case, the sick person should seek assistance from new medical centers. In fact, there are now drugs that could – if Allah wills – cure such diseases. 
There are many different conditions that are recognized as mental illnesses. The more common types include:
Anxiety disorders: People with anxiety disorders respond to certain objects or situations with fear and dread, as well as with physical signs of anxiety or panic, such as a rapid heartbeat and sweating. An anxiety disorder is diagnosed if the person's response is not appropriate for the situation, if the person cannot control the response, or if the anxiety interferes with normal functioning. Anxiety disorders include generalized anxiety disorder, panic disorder, social anxiety disorder, and specific phobias.
Mood disorders: These disorders, also called affective disorders, involve persistent feelings of sadness or periods of feeling overly happy, or fluctuations from extreme happiness to extreme sadness. The most common mood disorders are depression, bipolar disorder, and cyclothymic disorder.
Psychotic disorders: Psychotic disorders involve distorted awareness and thinking. Two of the most common symptoms of psychotic disorders are hallucinations -- the experience of images or sounds that are not real, such as hearing voices -- and delusions, which are false fixed beliefs that the ill person accepts as true, despite evidence to the contrary. Schizophrenia is an example of a psychotic disorder.
Eating disorders: Eating disorders involve extreme emotions, attitudes, and behaviors involving weight and food. Anorexia nervosa, bulimia nervosa, and binge eating disorder are the most common eating disorders.
Impulse control and addiction disorders: People with impulse control disorders are unable to resist urges, or impulses, to perform acts that could be harmful to themselves or others. Pyromania (starting fires), kleptomania (stealing), and compulsive gambling are examples of impulse control disorders. Alcohol and drug are common objects of addictions. Often, people with these disorders become so involved with the objects of their addiction that they begin to ignore responsibilities and relationships.
Personality disorders: People with personality disorders have extreme and inflexible personality traits that are distressing to the person and/or cause problems in work, school, or socialrelationships. In addition, the person's patterns of thinking and behavior significantly differ from the expectations of society and are so rigid that they interfere with the person's normal functioning. Examples include antisocial personality disorder, obsessive-compulsive personality disorder, and paranoid personality disorder.
Obsessive-compulsive disorder (OCD):People with OCD are plagued by constant thoughts or fears that cause them to perform certain rituals or routines. The disturbing thoughts are called obsessions, and the rituals are called compulsions. An example is a person with an unreasonable fear of germs who constantly washes his or her hands.
Post-traumatic stress disorder (PTSD):PTSD is a condition that can develop following a traumatic and/or terrifying event, such as a sexual or physical assault, the unexpected death of a loved one, or a natural disaster. People with PTSD often have lasting and frightening thoughts and memories of the event, and tend to be emotionally numb.
Stress response syndromes(formerly called adjustment disorders):Stress response syndromes occur when a person develops emotional or behavioral symptoms in response to a stressful event or situation. The stressors may include natural disasters, such as an earthquake or tornado; events or crises, such as a car accident or the diagnosis of a major illness; or interpersonal problems, such as a divorce, death of a loved one, loss of a job, or a problem withsubstance abuse. Stress response syndromes usually begin within three months of the event or situation and ends within six months after the stressor stops or is eliminated.
Dissociative disorders: People with these disorders suffer severe disturbances or changes in memory, consciousness, identity, and general awareness of themselves and their surroundings. These disorders usually are associated with overwhelming stress, which may be the result of traumatic events, accidents, or disasters that may be experienced or witnessed by the individual. Dissociative identity disorder, formerly called multiple personality disorder, or "split personality," and depersonalization disorder are examples of dissociative disorders.
Factitious disorders: Factitious disorders are conditions in which a person knowingly and intentionally creates or complains of physical and/or emotional symptoms in order to place the individual in the role of a patient or a person in need of help.
Sexual and gender disorders: These include disorders that affect sexual desire, performance, and behavior. Sexual dysfunction, gender identity disorder, and the paraphilia’s are examples of sexual and gender disorders.
Somatic symptom disorders: A person with a somatic symptom disorder, formerly known as a psychosomatic disorder orsomatoform disorder, experiences physical symptoms of an illness or of pain, even though a doctor can find no medical cause for the symptoms.
Tic disorders: People with tic disorders make sounds or display body movements that are repeated, quick, sudden, and/or uncontrollable. (Sounds that are made involuntarily are called vocal tics.) Tourette's syndrome is an example of a tic disorder.
Other diseases or conditions, including various sleep-related problems and many forms of dementia, including Alzheimer's disease, are sometimes classified as mental illnesses, because they involve thebrain. 
To determine a diagnosis and check for any related complications, you may have:
· A physical exam. Your doctor will try to rule out physical problems that could cause your symptoms.
· Lab tests. These may include a check of your thyroid function or a screening for alcohol and drugs, for example.
· A psychological evaluation. A doctor or mental health provider talks to you about your symptoms, thoughts, feelings and behavior patterns. You may be asked to fill out a questionnaire to help answer these questions. 
Sometimes it's difficult to find out which mental illness may be causing your symptoms. But taking the time and effort to get an accurate diagnosis will help determine the appropriate treatment.
The defining symptoms for each mental illness are detailed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published by the American Psychiatric Association. This manual is used by mental health providers to diagnose mental conditions and by insurance companies to reimburse for treatment.
The main classes of mental illness are:
· Neurodevelopmental disorders. This class covers a wide range of problems that usually begin in infancy, childhood or the teenage years. Examples include autism spectrum disorder, attention-deficit/hyperactivity disorder (ADHD) and learning disorders.
· Schizophrenia spectrum and other psychotic disorders.Psychotic disorders cause detachment from reality (delusions, paranoia and hallucinations). The most notable example is schizophrenia, although other classes of disorders can be associated with detachment from reality at times.
· Bipolar and related disorders. This class includes disorders with alternating episodes of mania — periods of excessive activity, energy and excitement — and depression.
· Depressive disorders. These include disorders that affect how you feel emotionally, such as the level of sadness and happiness. Examples include major depressive disorder and premenstrual dysphoric disorder.
· Anxiety disorders. Anxiety is an emotion characterized by the anticipation of future danger or misfortune, accompanied by feeling ill at ease. This class includes generalized anxiety disorder, panic disorder and phobias.
· Obsessive-compulsive and related disorders. These disorders involve preoccupations or obsessions and repetitive thoughts and actions. Examples include obsessive-compulsive disorder, hoarding and hair-pulling disorder (trichotillomania).
· Trauma- and stressor-related disorders. These are adjustment disorders in which a person has trouble coping during or after a stressful life event. Examples include post-traumatic stress disorder (PTSD) and acute stress disorder.
· Dissociative disorders. These are disorders in which your sense of self is disrupted, such as with dissociative identity disorder and dissociative amnesia.
· Somatic symptom and related disorders. A person with one of these disorders may have physical symptoms with no clear medical cause, but the disorders are associated with significant distress and impairment. The disorders include somatic symptom disorder (previously known as hypochondriasis) and factitious disorder.
· Feeding and eating disorders. These disorders include disturbances related to eating, such as anorexia nervosa and binge-eating disorder.
· Elimination disorders. These disorders relate to the inappropriate elimination of urine or stool by accident or on purpose. Bedwetting (enuresis) is an example.
· Sleep-wake disorders. These are disorders of sleep severe enough to require clinical attention, such as insomnia, sleep apnea and restless legs syndrome.
· Sexual dysfunctions. These include disorders of sexual response, such as premature ejaculation and female orgasmic disorder.
· Gender dysphoria. This refers to the distress that accompanies a person's stated desire to be another gender.
· Disruptive, impulse-control and conduct disorders. These disorders include problems with emotional and behavioral self-control, such as kleptomania or intermittent explosive disorder.
· Substance-related and addictive disorders. These include problems associated with the use of alcohol, caffeine, tobacco and drugs. This class also includes gambling disorder.
· Neurocognitive disorders. Neurocognitive disorders affect your ability to think and reason. This class includes delirium, as well as neurocognitive disorders due to conditions or diseases such as traumatic brain injury or Alzheimer's disease.
· Personality disorders. A personality disorder involves a lasting pattern of emotional instability and unhealthy behavior that causes problems in your life and relationships. Examples include borderline personality disorder and antisocial personality disorder.
· Paraphilic disorders. These disorders include sexual interest that causes personal distress or impairment or causes potential or actual harm to another person. Examples are sexual sadism, voyeuristic disorder and pedophilic disorder.
· Other mental disorders. This class includes mental disorders that are due to other medical conditions or that don't meet the full criteria for one of the above disorders. 
Signs and symptoms of mental illness can vary, depending on the particular disorder, circumstances and other factors. Mental illness symptoms can affect emotions, thoughts and behaviors.Examples of signs and symptoms include:
· Feeling sad or down
· Confused thinking or reduced ability to concentrate
· Excessive fears or worries, or extreme feelings of guilt
· Extreme mood changes of highs and lows
· Withdrawal from friends and activities
· Significant tiredness, low energy or problems sleeping
· Detachment from reality (delusions), paranoia or hallucinations
· Inability to cope with daily problems or stress
· Trouble understanding and relating to situations and to people
· Alcohol or drug abuse
· Major changes in eating habits
· Sex drive changes
· Excessive anger, hostility or violence
· Suicidal thinking
Sometimes symptoms of a mental health disorder appear as physical problems, such as stomach pain, back pain, headache, or other unexplained aches and pains. 
In most cases, a mental illness won't get better if you try to treat it on your own without professional care. But you can do some things for yourself that will build on your treatment plan:
· Stick to your treatment plan. Don't skip therapy sessions. Even if you're feeling better, don't skip your medications. If you stop, symptoms may come back. You could also have withdrawal-like symptoms if you stop a medication too suddenly. If you have bothersome medication side effects or other problems with your treatment, talk to your doctor before making changes.
· Avoid alcohol and drug use. Using alcohol or illegal drugs can make it difficult to treat a mental illness. If you're addicted, quitting can be a real challenge. If you can't quit on your own, see your doctor or find a support group to help you.
· Stay active. Exercise can help you manage symptoms such as depression, stress and anxiety. Physical activity can also counteract the effects of some psychiatric medications that may cause weight gain. Consider walking, swimming, gardening or any form of physical activity that you enjoy. Even light physical activity can make a difference.
· Don't make important decisions when your symptoms are severe. Avoid decision-making when you're in the depth of mental illness symptoms, since you may not be thinking clearly.
· Determine your priorities. You can reduce the impact of your mental illness by managing your time and energy. Cut back on obligations when necessary and set reasonable goals. Give yourself permission to do less when your symptoms are bad. You may find it helpful to make a list of daily tasks, use sticky notes as reminders, or use a planner to structure your time and stay organized.
· Learn to adopt a positive attitude. Focusing on the positive things in your life can make your life better and may even improve your health. Try to accept changes when they occur, and keep problems in perspective. 
There's no sure way to prevent mental illness. However, if you have a mental illness, taking steps to control stress, to increase your resilience and to boost low self-esteem may help keep your symptoms under control. Follow these steps:
· Pay attention to warning signs. Work with your doctor or therapist to learn what might trigger your symptoms. Make a plan so that you know what to do if symptoms return. Contact your doctor or therapist if you notice any changes in symptoms or how you feel. Consider involving family members or friends to watch for warning signs.
· Get routine medical care. Don't neglect checkups or skip visits to your family health care provider, especially if you aren't feeling well. You may have a new health problem that needs to be treated, or you may be experiencing side effects of medication.
· Get help when you need it. Mental health conditions can be harder to treat if you wait until symptoms get bad. Long-term maintenance treatment also may help prevent a relapse of symptoms.
· Take good care of yourself. Sufficient sleep, healthy eating and regular physical activity are important. Try to maintain a regular schedule. Talk to your provider if you have trouble sleeping or if you have questions about diet and exercise. 
People today are exposed to many daily frustrations. They are also propounded with many electrostatic charges from the atmosphere. These charges are precipitated on the central nervous systems (CNS) which becomes supersaturated. One has to get rid of these extra charges, otherwise, there is the possibility of headaches, neck aches, muscle spasms, etc. The use of anti-depressants, tranquilizers and other mood altering drugs could be reduced or eliminated with the practice of Sujood.
It can be due to extra electrostatic charges is by dissipating them and discharging them from the body. The frontal areas of the brain are those that control abstract thought, creativity, conscience, and personality. Therefore, "grounding" oneself by putting the forehead (the frontal portion of the brain) on the ground during Sujood (prostration) has beneficial medical (grounding) properties. The action of putting the forehead, nose, hands, knees, and toes all in contact with the ground at the same time during Sujood will result in a calm feeling resulting from dissipation of the electromagnetic energy."
This in turn results in better mental health, not only because of the physical activity, but due to the spiritual process also.
Whenever Allah's Messenger (ﷺ) became sick, he would recite Mu'awwizat (Surah Al-Falaq and Surah An- Nas) and then blow his breath over his body. When he became seriously ill, I used to recite (these two Suras) and rub his hands over his body hoping for its blessings. Sahih al Bukhari 5016 
Supplication for healing (any disease)
Allah's Messenger (ﷺ) used to read this also:
اللَّهُمَّ رَبَّ النَّاسِ أَذْهِبِ الْبَاسَ، اشْفِهِ وَأَنْتَ الشَّافِي، لاَ شِفَاءَ إِلاَّ شِفَاؤُكَ، شِفَاءً لاَ يُغَادِرُ سَقَمًا "”
Allahumma Rabban-naas Azhibil baas Shaafi wa antash-shaafi, la shifa’a illa shifaa’uka, shifa’an la yughadiru saqama.
Meaning: O Allah! The Lord of the people, the Remover of trouble! (Please) cure (Heal) (this patient), for You are the Healer. None brings about healing but You; a healing that will leave behind no ailment. Sahih al Bukhari Vol #7, Hadith #5743 
Allah Knows Best