1. A system for diagnosing Attention Deficit Hyperactivity Disorder (ADHD) in a patient, comprising: a signal acquisition subsystem including a sensor for obtaining an ocular autonomic micro-tremor signal; a signal processing subsystem for creating an ocular autonomic waveform signature from the acquired ocular autonomic micro-tremor signal; a subsystem for accessing an ADHD reference library of ocular autonomic waveform signatures collected and measured from a plurality of previously diagnosed ADHD patients, wherein the signal acquisition subsystem creates the ADHD reference library by obtaining an ocular autonomic micro tremor signal from the plurality of previously diagnosed ADHD patients and the signal processing subsystem creates ocular autonomic waveform signatures from the acquired ocular autonomic micro-tremor signals of the plurality of previously diagnosed ADHD patients; and a correlation subsystem for comparing and correlating the patient's ocular autonomic waveform signature with the waveform signatures of the plurality of previously diagnosed ADHD patients in the ADHD reference library, whereby a match between the patient's ocular autonomic waveform signature and the waveform signatures of the previously diagnosed ADHD patients in the ADHD reference library provides a diagnosis of ADHD.