Psychiatry has been shifting to a model that is designed to identify psychiatric pathologies in most of the population. If there are no biological markers or indicators then the psychiatric diagnostic manual puts together patterns of behavior. Once it's characterized" there's, very conveniently, a drug for that.
Using this Big-Pharma driven model of diagnosis creation, I'm partially playfully and partially seriously offering some potential diagnostic categories for the very wealthy. Remember, this is half satire, I am not a mental health expert and I'm not doing serious references to support this exercise. Also, there are absolutely wealthy people who are decent people. The problem is, as Lord Acton observed, "Power corrupts and absolute power corrupts absolutely." I would argue that there are so many risks and dangers in giving people the ability to accumulate huge amounts of money and the power that comes with it, that we should put limits on wealth and even tighter limits on inheritance of wealth.
The article wraps up by discussing the enablers of these "mental illnesses-- call them co-dependents? I've offered another diagnosis as well.
Hoarding-- In a conversation with Thom Hartmann last sumer, he suggested the idea that billionaires might be hoarders. People with hundreds of millions or billions of dollars are, in some ways like the people we see on the hoarder reality TV shows, with houses so packed with crap that they have to walk sideways or climb over piles. Hoarders can't let go of or throw away anything they've touched or that has their name on it. The other day, a local hoarder died in a house fire because he could not escape through the piles in his house. These people are often stuck in their homes and lose connection with other people. Hoarding is one pathological way to control their lives. Hoarding might be considered a variant of obsessive compulsive disorder.
Drugs of choice: Anti-depressants, anti-anxiety, possibly mood treatment medications like Abilify.
Narcissism. Narcissists are a**holes who think the world revolves around them They are similar to psychopaths but they have some, though not much empathy. Wikipedia (link is bolded) describes some of the characteristics of Narcissists:
Hotchkiss identified what she called the seven deadly sins of narcissism: 
- Shamelessness : Shame is the feeling that lurks beneath all unhealthy narcissism, and the inability to process shame in healthy ways.
- Magical thinking : Narcissists see themselves as perfect, using distortion and illusion known as magical thinking. They also use projection to dump shame onto others.
- Arrogance : A narcissist who is feeling deflated may reinflate by diminishing, debasing, or degrading somebody else.
- Envy : A narcissist may secure a sense of superiority in the face of another person's ability by using contempt to minimize the other person.
- Entitlement : Narcissists hold unreasonable expectations of particularly favorable treatment and automatic compliance because they consider themselves special. Failure to comply is considered an attack on their superiority, and the perpetrator is considered an "awkward" or "difficult" person. Defiance of their will is a narcissistic injury that can trigger narcissistic rage .
- Exploitation : Can take many forms but always involves the exploitation of others without regard for their feelings or interests. Often the other is in a subservient position where resistance would be difficult or even impossible. Sometimes the subservience is not so much real as assumed.
- Bad boundaries : Narcissists do not recognize that they have boundaries and that others are separate and are not extensions of themselves. Others either exist to meet their needs or may as well not exist at all. Those who provide narcissistic supply to the narcissist are treated as if they are part of the narcissist and are expected to live up to those expectations. In the mind of a narcissist there is no boundary between self and other.
Medications: Medscape states:
Although no psychiatric medications are specifically approved for the treatment of narcissistic personality disorder (NPD), patients often benefit from the use of such medications to help alleviate certain symptoms associated with this disorder or to manage concomitant axis I diagnoses. Medications that may be considered include antidepressants (specifically, selective serotonin reuptake inhibitors [SSRIs]), antipsychotics, and mood stabilizers.
Dynasty Disorder: An NIH/NIMH report on children of the wealthy reported serious, alarming problems. Since many of the wealthy are children of the wealthy-- think Waltons, Kochs, Rockefellers-- to name a few, and American Dynasties are growing, these studies may apply to the adult children of the wealthy too. here's a sample from the report, titled The Culture of Affluence: Psychological Costs of Material Wealth: