One major benefit of seeking professional health care (mental or otherwise) is that a professional is often in a better position to accurately diagnose your problem, and point you towards the best treatments available for helping you get better than you are. You may have heard the term "diagnosis" before. A diagnosis is a label given to a particular illness or issue that you might have. Diagnoses are identified by their symptoms, which are the complaints that people make when talking to their doctors. Mental health diagnoses have been organized in a book called the Diagnostic and Statistical Manual of Mental Disorders (or DSM, for short). In the DSM, each diagnosis falls into one of several possible categories, including, but not limited to mood disorders (such as depression and bipolar disorder); schizophrenia and other psychotic disorders; anxiety disorders (including panic attacks, phobias, post traumatic stress disorders and obsessive-compulsive disorders); dissociative disorders (including multiple personality and amnesia); impulse control disorders (such as compulsive hair pulling, or fire-setting); personality disorders (such as borderline personality and narcissism); and substance related disorders (such as alcohol or methamphetamine addiction).
One of the first things that a mental health professional will do when you visit him or her is to diagnose you. He or she will listen to you describe your issues and complaints, and fit them into one or more of the known illness categories described in the DSM. Diagnosing your issues is important, because it helps professionals to know which interventions to suggest to you (from among thousands that are possible) that will have the best chance of helping you to get better. Professionals know which interventions to choose based on your diagnoses because they are familiar with the work that thousands of scientists and clinicians have previously done to match particular interventions with particular diagnoses.
For example, let's say that you visit a mental health professional and complain about the following symptoms: You're experiencing severe mood swings, are feeling overly energetic lately, can't concentrate, are spending money recklessly, are increasingly irritable with other people, aren't abusing drugs or alcohol and have gone through similar episodes before in your life. Your professional will listen to what you have to say, and will ask questions about your experience to clarify things or get you to talk about things that might be important but which you've not mentioned spontaneously. He or she will likely want to learn about your past history of similar problems and may request medical records from other doctors if any exist. He or she may want to order several medical tests be done to determine if there is a physical cause, such as drug abuse, brain damage, hyperthyroidism or similar problem, that can explain your symptoms If no physical cause can be determined, you would probably be diagnosed with a psychiatric disorder that most closely fits with your presentation (in this case, possibly bipolar disorder). Your professional will know that certain treatments are known to be helpful for bipolar disorder (particular medicines such as "mood stabilizers" and "antidepressants", in this case) and will help you obtain those treatments, along with proper instructions and monitoring for their use. Other treatments that are known to be less helpful for treating bipolar disorder will not be offered. Alternatively, If you go to a professional and say that your major symptom is anxiety, that professional might diagnose an anxiety disorder, and create a treatment plan for you that includes interventions that are known to be helpful for treating anxiety disorders, including cognitive therapy, relaxation techniques, exercise programs, and anti-anxiety medication.
Only a doctor or similar trained and experienced mental health professional is qualified to make a true diagnosis and therefore to make treatment recommendations. Diagnoses are complex and difficult to make correctly. It takes many years of concentrated study to learn how to accurately diagnose patients, and even then, different doctors will sometimes make different diagnoses for the same patient. For example, the family of psychotic disorders are characterized by a variety of symptoms, including delusions, hallucinations and regressed (or "primitive") odd behaviors. Psychoses occur across many different types of disorders, including substance abuse, severe depression; bipolar disorder as well as schizophrenia and related psychotic disorders. When diagnosing schizophrenia, for example, it is necessary to rule out (or exclude) the possibility that other disorders (like bipolar disorder) or drugs (like cocaine) might be causing the problem. To make matters even more complicated, the very definitions of the different diagnoses change across time, as the DSM gets revised and rewritten. For example, not so long ago, homosexuality was a diagnosable illness defined in the DSM. This diagnosis was removed from the DSM in the 1980s when it became clear that it had been included there more because of cultural prejudice than for scientific reasons. Today, evidence from the biological sciences suggests that most homosexuality is biologically determined and thus a normal variation of human sexuality and not a disorder at all. It is rare these days to find a professional mental health provider who believes homosexuality is a mental illness.