Do Nightmares Indicate Psychological Disturbance?

No, this was often perceived to be the case, but it is now thought that people have nightmares more commonly than we can remember, ie we have nightmares frequently but do not remember them when we wake.  Moreover, the occurrence of nightmares has little to do with our levels of anxiety when awake.  
However, some people may be susceptible to nightmares.  These are often referred to as 'thin boundaried people'.   They are usually very sensitive, artistic and creative, often quite vulnerable to outside influences.  However, they do not deal with negative emotions in the same way as other people.  They allow fears and angers to grow and become more intense.
These emotions are then 'expressed' through the form of nightmares.  But they do not have a 'psychological disturbance, necessarily, just a different way of dealing with the negative aspects of life.
If nightmares are incredibly intense or seriously impeding quality of sleep then medical advice should be sought.

Yes although not all psychologist agree.  From my knowledge base if one constantly have nightmares it means that the mind is not still during the REM rapid eye movement phase.  Its volatility means that that person has several unresolved issues; things which they fear that they cannot speak to anyone about in his/her a wake hours.  By this notion persons who are gregarious tend to have less nightmares and by logic those who tend to be recluse then to have more.  Her is  sample test.  If you get nightmares often try to grab a pen and paper and draw. Usually a disturbed person will draw broken lines followed by indiscernible circles and boxes.  On the contrary those with pleasant dreams might find that they are better artiste than they though they could ever be,