Believe it or not, your doctor cannot make a determination that you are disabled. Disability is a legal determination reserved solely to the Social Security Administration.
However, there are some things your doctor can do to help you better show to the Social Security Administration that you are incapable of working.
First, your doctor can accurately describe your mental or physical conditions. Rather than stating you are "disabled" or unable to work, he or she can state that you are unable to stand for more than ten minutes, you are only able to walk one city block before having to sit down and rest, you are unable to lift more than five pounds, or you have trouble following even simple instructions, etc.
These allow the Social Security Administration to understand how your conditions affect your ability to do basic work activities. The more restrictions you have, the better your chance of being found disabled.
Second, you need to have records from a specialist or your actual treating physician. Understandably, it is often very difficult financially to afford to see a specialist, especially when a person has been out of work for months and maybe even years. However, the Social Security Administration gives more weight to some treating sources than it does to others. For example, your medical records will carry more weight if your doctor actually noted and signed them rather than his or her nurse or nurse practitioner. This is especially true when a nurse practitioner gives a diagnosis. Under Social Security's watchful eye, it believes those records that come from a recognized treating sources more than other others.
Third, here is something only you can do...Go to the doctor and seek treatment for your impairment(s) or condition(s). Sadly, as people become more disabled, their funds dry up and they can no longer afford to seek medical treatment. It is very important that your medical records are as up to date as possible, especially if you have been denied twice and need to appeal your case to the hearing level. Even if it means going to the county emergency room once every three months, do so in order to show you are not only seeking treatment but keeping your records up to date enough to allow the claims examiner or the judge to rule in your favor.