Disclaimer: I own nothing but my words, so suing me will bring you no happiness. I appreciate the chance to use others' creations for my own healthy amusement.

"HA HA HA HA HA HA"

John snapped awake, sitting bolt upright in his bed. In a state of semi-awareness, he brought his attention to the digital clock on the table nearby. It read 2:32. He shook his head, blinking, and tried to decide what he'd heard.

"HO HO HO HO HO HO!"

What the…

"HA HE HA HE HA HE HA HE!"

"I am going to have to shoot him." John sighed, slowly coming to the realization that he wasn't going back to sleep after five continual minutes of loud, uninterrupted pseudo-laughter percolated up the stairs of 221B. He shifted clumsily out of bed, took his thin robe from the back of his single chair, and pulled it on over his pajamas. "He does this just to see if I will actually kill him. I know he does. It's some type of masochistic experiment."

"HE HE HE HE HE HE HE"

"Either that; or he's finally admitting he's an evil genius, and putting some time into the laugh." John wrenched open the door to his small room and paced down the narrow staircase to the living area. Bracing himself, he opened the door. He began to say "Sherlock, the violin is bad enough…" but his voice stuttered out. John's erstwhile flatmate was standing, back straight and head up, in the center of the living room floor. Sherlock's arms were flung up over the tall man's head, as if he were attached by invisible string to the ceiling. Another 'laugh' began.

"HAR HAR HAR HAR HAR HAR HAR."

John pulled his eyebrows from his hairline and his chin from his chest with an act of will, took a slow breath, and began again. "Sherlock, what the He.."

"HE HO HE HO HE HO HA HA HA HA HA!"

Well, that one was creative. John interjected quickly "Sherlock, shut up." It didn't work.

"HE HE HE HO HO HO HA HA HA! Ooof!" The last came out in a rush of wind as John's shoulder intersected with Sherlock's solar plexus. Sherlock's eyes came down to his flatmate's as Sherlock's hands reached to still his stomach. "John, what on earth are you doing up at this hour?"

John scowled at Sherlock, not giving his friend the benefit of an answer. "WHAT…" he breathed in again, bringing his tone to something approaching human, "What is this all about?"

Sherlock looked around himself, taking in the standard disarray of the flat's living space with a befuddled expression. "This? This what?"

"This…this THIS! HA HA HA HA?"

"No." Sherlock moved to John, lifting the shorter man's arms straight up and positioning John's chin upward. "You need to bring it from here," he said, tapping John's stomach. "As if you're pushing the laughter from your diaphragm, through your…" he stepped back, noting for the first time John's expression. "You are unhappy. That's not how it's supposed to work." He nearly leapt to a small table under the window, consulting a printed page covered in highlighting and scribbles. He checked it, looked back quickly to his flatmate, and grabbed a pen.

John harrumphed, dropping his arms and resignedly heading toward the kitchen and the kettle. "That's not how what is supposed to work?"

"Laughing should make you happy, and reduce your stress. You are not looking less stressed."

"No." John began, thinking (not for the first time) that Sherlock was unlikely ever to get a handle upon human emotions. "Happiness makes one laugh, not the other way about. You've got it backwards."

"Not according to John Morreall who found that feigned laughter is interpreted in the body as any other type of laughter. The act of feigning laughter causes release of dopamine, similar to laughter accomplished in more natural ways. And Toda and Kusakabe et al. showed that laughter reduces stress and increases one's immune function."

"Excuse me?"

Sherlock took a tone not unlike that John had used a moment before; the voice one uses when explaining a difficult idea to a small child. "Toda, Kusakabe, Nagasawa, Kitamura and Morimoto, Osaka University School of Medicine, 2007. They found that the act of laughing releases chromogranin A into the bloodstream, thereby decreasing stress and increasing relaxation in research subjects." He shoved the printed pages into John's hands, incidentally taking the mug John had been readying for tea. "You, as a doctor, should understand the importance of stress reduction to prevent illness."

John glanced at the study he now held. Effect of laughter on salivary endocrinological stress marker chromogranin A, Toda and Kusakabe et al. He tossed the pages upon the counter, grabbed another mug from a cabinet, and poured hot water over two tea bags. "You really do want me to kill you, don't you?"

"Stress, John. You must reduce your stress levels. Stress is bad for the immune system." Sherlock waved at the pages on the counter dismissively as he headed toward his bedroom. "Good night John," he said lightly, as the door closed behind him.

Yes, these are real studies. Google Scholar will find them both for you. The show Sherlock is funny. Therefore it is good for my health. See? Television is good for us!