The five different categories classified by the Autism Spectrum Disorder (ASD) all have common, distinguishable symptoms that join them together. These signs are most typically observed during infancy and early childhood and in some degrees of the spectrum, are carried through to adulthood.

Studies show the hormones, vasopressin and oxytocin, are responsible for social and emotional connections and by targeting these hormones, medication may be able to help alleviate the difficulties experienced in relational interactions.
           Failure to maintain and establish friendships/relationships
           Does not understand personal space boundaries
           Has difficulty following/understanding jokes or sarcasm
           Avoiding eye contact
           Avoiding or resisting physical contact
           Difficulty sleeping
           Need for routine
           Lack of empathy
           Lack of interest in sharing enjoyment
           Preoccupation with specific interests
           Repetition of words or behaviors
Signs of autism will vary across the spectrum. There are some patients who are able to learn and adapt completely and are able to be completely independent, while others have a more severe progression of the disorder and require consistent care.