Magic in the Water

Do we see Shared Psychotic Disorder here?

Frank appears intoxicated. (0:00)

Radio talk show host Jack Black tells caller Maggie, "... testosterone is going to destroy the world?" 
”... speaking as... your radio therapist...” 
Caller #2: ”... call yourself a therapist... isn’t modern therapy.” 
Jack: ”Modern therapy is the problem...” 
Caller #2: ”... work I’ve done on my inner child...” 
Jack: ”... advice for your inner child...” (0:02)

Their mother Beth tells Jack’s kids Ashley and Joshua, "Hey, don't worry..." (0:05)

Sign: "PSYCHIATRIST" 
Group psychotherapy (0:08)

Joshua: "Looks like some demented teepee..." (0:10)

Josh answers Jack, referring to Ashley, "Hormones." (0:13)

Jack tells Ashley, "Don’t worry about it, honey..." 
Joe Pickled Trout, referring to Uncle Kipper: ”... We keep him sedated.” (0:16)

Books: "HANDBOOK OF PSYCHIATRIC THERAPIES," “B. F. Skinner” (0:22)

Psychiatrist Wanda Bell answers Jack, showing him a prescription bottle, "Uh, I have a patient here, sedatives." 
”Well, actually I’m a psychiatrist.” 
”You’re a psychiatrist?” 
Jack: ”... How could anyone be neurotic up here?...” 
Wanda: ”... practicing general medicine... group of men who all have an identical psychosis.” 
”... believe they’ve been inhabited by a lake monster.” (0:23)

Ashley tells the monster, "... highway perverts." (0:28)

Jack appears to have suffered a traumatic head injury. 
Wanda tells Ashley, referring to Jack, "... a mild craniocerebral trauma, a concussion.” 
Jack regains consciousness.
Jack: ”I had the weirdest dream.” (0:30)

Josh, referring to a boy: "Dad, he’s a moron." (0:37)

Wanda, in group psychotherapy: "Frank,... you were describing the euphoria you experienced during your hallucination with the monster..." 
Patient: ”Frank, don’t worry.” 
Patient: ”I’m not a nut.” (0:38)

Wanda tells Kipper’s nurse, "... Here’s the new supply of sedatives." (0:51)

Wanda asks Jack, "... Do you always make fun of your patients?" (0:52)

Wanda administers a projective test to Jack.
Jack answers Wanda, ”... That was a dream...” 
Wanda: ”... you have taken on the psychoses of my other patients.” 
Jack: ”That was just a dream...” (0:53)

Josh tells Ashley, referring to Jack, "... get him locked up for good... in some loony bin..." 
Josh rages. (0:57)

Josh tells Ashley, referring to Kipper: "This guy’s gone wacko." 
”... artificial sugar high...” 
Kipper puts pills in the nurse’s coffee. (0:59)

Kipper asks Josh and Ashley, "... Did you ever have dreams about flying?" 
”... putting toxins in the lake.” (1:02)

Ashley tells Jack, "... you’re not crazy..." 
Jack: ”... It was only a dream.”
Prescription bottle (1:05)

Mack Miller: "That colossal idiot." (1:13)

Miller tells Wright and Lefty Hardy, "That little idiot..." 
”... you moron...” (1:16)

Jack tells the kids, "... This place was in my dream..." (1:21)

Josh: "It could be the toxins, Dad." (1:23)

The sheriff tells Jack, "Don’t be silly..." (1:26)

Ashley: "Is this one of those metaphors, Dad?" 
Jack: ”When did you get so smart?” (1:31)