You want to know if there is a pattern to the disorders, for instance if post-traumatic stress disorder comes before depression. About 90% of those who suffer from chronic post-traumatic stress disorder also fall into deep depression.
Regarding the other disorders, I cannot answer your question. We observe various patterns. A person might begin by consuming large amounts of alcohol, and then fall into depression. We see all types of patterns.
Different treatments are applied, based on the most serious of the problems diagnosed. However, treatments can serve more than one purpose. For instance, anti-depressants are used to treat post-traumatic stress disorder as well as depression. In such cases, the treatment, if drugs are involved, is simplified.