Hou et al. [51] examined reward circuitry dopamine transporter levels in Internet addicts compared
to a control group. The Internet addicts comprised five males (mean age = 20.4, SD = 2.3) whose mean
daily Internet use was 10.2 h (SD = 1.5) and who had suffered from Internet addiction for more than
six years. The age-matched control group comprised nine males (mean age = 20.4, SD = 1.1 years),
whose mean daily use was 3.8 h (SD = 0.8 h). The authors performed 99mTc-TRODAT-1 single
photon emission computed tomography (SPECT) brain scans using Siemens Diacam/e.cam/icon
double detector SPECT. They reported that reduced dopamine transporters indicated addiction and that
there were similar neurobiological abnormalities with other behavioral addictions. They also reported
that striatal dopamine transporter (DAT) levels decreased among Internet addicts (necessary for
regulation of striatal dopamine levels) and that volume, weight, and uptake ratio of the corpus striatum
were reduced relative to controls. Dopamine levels were reported to be similar to people with
substance addictions and that Internet addiction “may cause serious damages to the brain” ([51], p. 1).
This conclusion cannot be seen as entirely accurate for the directionality of the reported effect cannot
be established with the utilized method.