Is there such a thing as a condition that exhibits symptoms approximately the opposite of psychological depression?
By this of course I do not mean to imply that psychological depression is merely the state of being sad or miserable - I know it’s nothing like as simple as that, however, I would like to know if there is such a thing as a disorder (if indeed that is an appropriate term) that is characterised by heightened levels of mood, self-esteem, pleasure, interest, hope, assurance, etc.
Try mania.
yes absolutely. What used to be called Manic-Depression and is now called Bipolar disorder. Full blown Mania is very rare but a milder form called hypomania in conjunction with depression is relatively common. During hypomania, people experience heightened confidence, diminished need to sleep, may have many creative ideas, increased sex drive + more.
If that all sounds great, its really not. If you speak to anyone who has had bipolar and a hypomanic period the reality is not pretty. Inevitably sufferers find out that most of the ideas during their hypomanic period are worthless or self destructive, but the period of exaggerated confidence can last months. When it wears off you might have destroyed a relationship, been fired, or lost ten’s of thousands on what you believed was a sure fire business idea.
Bipolar sufferers have a higher suicide rate than people with just simple depression, and most of the suicides occur during hypomanic or manic phases… not depressed phases.
I believe the psychiatric term that you are looking for is “mania” or “hypo-mania.”
It’s fun as all get out for the first couple of days (as long as you don’t get fired, offend everyone you know, run into troubles with the law, get killed engaging in high-risk behavior, etc.) but eventully you just “crash” from complete exhaustion caused by a severe lack of sleep.
Between the “mania” and the “crash” its just lousy–monster headaches, exhaustion, lack of sleep, very tired emotional state, no fun at all, etc.
Not quite what you are looking for, but there is also a psychological condition which was described as pronoia
Oliver Sacks also describes people with Korsakoff’s syndrome (profound loss of short-term memory) as typically having a sort of happy-go-lucky demeanor, punctuated by brief moments of puzzlement before they lose the thread again.
Naguib Mahfouz wrote a short story about a man who one day woke up and discovered he was happy. He continued being happy all day, and started to worry about it. He went to a shrink who said “These cases are very hard to treat, but there’s a possibility that with sustained therapy we may be able to reduce your happiness to a tolerable level.” It was a masterpiece of understated satire. 
I could call happiness pathological if it interfered with a person’s life.
Say they were so content with whatever their situation was that they were not driven to seek food, shelter, health care, etc. then I’d say their happiness would cause them to be likely to have bad outcomes.
Sort of like those individuals who feel no pain. They don’t notice their injuries, or subsequent infections which cause them to lose limb and life. But hey, nothing hurt.
Well, there’s Angelman Syndrome, which used to be called “Happy Puppet Syndrome.”
There is a birth defect which gives people elfen features. They tend to be very happy. But mentally, they never progress past childhood.
Alec Baldwin played a relentlessly, annoyingly upbeat guy like that on Friends once. Phoebe, briefly his girlfriend, finally exploded, “You’re like Santa Claus… on Prozac… in Disneyland… getting laid!”
Though not quite pure “happiness,” in college I recall learning about a man who suffered some type of brain damage which resulted in him experiencing a permanent state of blissful “oneness-with-the-universe.” IIRC, he abandoned his former life and went to live in some type of monastery or religious retreat center.
A quick googling brings me this: Selective brain damage modulates human spirituality
I wish I could remember more of the story, but hopefully that can provide a starting point…
Williams syndrome. There was an interesting thread from about a year ago that included a few people who’d had friends and coworkers with it: What’s it like to talk to someone with Williams Syndrome?
Fascinating. Never heard of that before.
Don’t know anything about medical terms, but my BIL is like this. ALWAYS smiling and upbeat to the point it’s friggin annoying as hell! Been that way ever since I first met him!
I don’t have a source, but I recall reading very clearly an anecdote told by a neurologist concerning a man who could not stop being happy. It was so severe that he would sometimes paradoxically become momentarily frustrated about being happy in spite of things that he ought to be grieving, such as his wife having recently died… he knew it was wrong, he tried to hold onto the frustration and grieving, but he ended up just unavoidably shrugging it off with a grin after a few moments.
It was due to some physical injury or disease to the brain… he had a lesion not on the amygdala but on one of the little bits that is very related to the amygdala. Wish I could remember, but I would have to reread at least three rather thick books of similar anecdotes to find it.
A frequent misunderstanding about Prozac is that it’s a “happy pill.” It just allows some people to feel normal (non-depressed).
Just as well. I don’t think Phoebe was licensed to practice medicine in the State of New York anyway.