Plasma cyclic AMP and cyclic GMP in childhood-onset psychoses.

Researchers drew blood from kids with autism and kids with typical development. They measured two tiny messengers in the plasma: cyclic AMP and cyclic GMP. The goal was to see if either molecule could act as a biological flag for autism.

Cyclic AMP was more than twice as high in the autism group. Cyclic GMP looked the same across groups. The jump in cyclic AMP only showed up in autism and related pervasive disorders, not in broader delays.

Catania et al. (1982) started the hunt two years earlier, finding a unique urinary peptide pattern in over half of autistic kids. Davison et al. (1984) moved the search from urine to blood and swapped peptides for cyclic nucleotides, keeping the same case-control logic.

Siniscalco et al. (2012) and Hu et al. (2018) later kept the blood focus but updated the targets. Dario found higher caspase proteins inside white blood cells. Chun-Chun found higher cytokines like Eotaxin in the plasma itself. Each study extends the idea that kids with autism carry measurable blood signals, while the exact molecule keeps changing with new lab tools.

Rutter et al. (1987) ran a near-replica design three years later, yet measured catecholamines instead of cyclic nucleotides. They saw higher plasma catecholamines in the same autistic group, supporting the broader claim that plasma chemistry shifts in autism even when the analyte differs.

You now have a 1984 blood marker that doubled in autism. No special prep, just a routine plasma sample. Pair this old finding with newer cytokine or caspase panels to build a multi-marker profile. Track cyclic AMP alongside behavior data to see if drops mirror treatment gains. The test is not diagnostic on its own, but it gives you an extra biological window that parents can understand: 'One of your child’s chemical messengers runs high.'