Why when I see something funny and start laughing, I get an overwhelming feeling of sadness and start crying?
MDE, pseudobulbar. The most common causes of alexithymia (unawareness of affect or inappropriate affect) is depression or other psychiatric disorders. However, neurologic disorders, such as pseudo bulbar affect, can result in inappropriate affective responses. If antidepressants are not effective, a neurologic workup is indicated.
Why, when I see something funny and start laughing, do I get an overwhelming feeling of sadness and start to cry?
Emotional Release. Many years ago joni mitchell sang a song called "people's parties" -- one of the lines was, "laughing and crying, you know it's the same release." in some ways this may be true -- freeing emotion from suppression can be a relief. But you may also have some sadness that's not being addressed, and needs to be cared for. Talk to someone about it -- many therapists available to help you process it.