The majority of people who file for disability benefits do not appeal if they are turned down for benefits. It's not surprising, given the fact that it's a lot of work to put together a complete medical history and work history, and it takes a long time to get an answer. The disability appeal process is long and difficult, even more so for those whose physical or mental health is deteriorating. Of course, if your application is denied, the best thing to do is to file an appeal. However, a whole lot of people simply give up and assume that their condition does not qualify them for benefits. But you should not assume that your denial has anything to do with your particular type of impairment.
If you didn't appeal, or you missed the appeal deadline, then by all means file a new claim, especially if your medical condition has deteriorated since you filed your first claim. One of the reasons so many claims that are denied by DDS are later approved by an administrative law judge (ALJ) is that the applicant's symptoms have deteriorated over time, and by the time the case gets to a hearing, the claimant is truly disabled per the SSA's definition.
When you reapply, be sure to include any new information that you think might help your case, including any recent medical treatment or diagnosis.
