A spectrum disorder in psychiatry is hard to define precisely but is a mental disorder having something to do with a spectrum of subtypes or closely related disorders. The spectrum model is proposed as a more coherent way of understanding psychiatric symptomatology.

The widely-used DSM and ICD manuals are generally limited to categorical diagnoses but do recognize some subsyndromal subtypes: schizotypal personality disorder, dysthymia and cyclothymia. Some proposed spectra include a bipolar spectrum, a schizophrenia spectrum, an autistic spectrum, a Post-Traumatic Stress Spectrum, an obsessive-compulsive spectrum, a social anxiety spectrum, and a Panic-Agoraphobia Spectrum. Other ‘higher-level’ spectra are often proposed, which categorise disorders in to even fewer overarching spectra. Template:WikiDoc Sources