Does Temperament Constitute a Risk Factor for Adult Attention Deficit Hyperactivity Disorder?

OBJECTIVE: The aim of this study was to examine the temperament characteristics of adults with attention deficit hyperactivity disorder (ADHD) and the relationship between ADHD subtypes and temperament. Additionally, the study aimed to investigate the relationship between childhood ADHD symptoms and temperament. METHODS: The study included 59 ADHD patients aged between 18 and 60 years and 44 healthy controls. All participants completed the Wender-Utah Rating Scale (WURS) and the Adult Attention Deficit Hyperactivity Disorder Diagnosis and Rating Scale. Temperament characteristics were assessed using the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-Autoquestionnaire scale (TEMPS-A). RESULTS: The ADHD group had significantly higher scores for cyclothymic, irritable, and anxious temperament compared to the control group (p<0.001). The number of individuals with cyclothymic, irritable, and anxious temperament was also significantly higher in the ADHD group (p=0.007, p=0.018, p=0.029, respectively). Positive correlations were found between cyclothymic and depressive temperament scores and WURS scores (r=0.278, p=0.033; r=0.326, p=0.012, respectively), between hyperthymic temperament scores and hyperactivity scores (r=0.399, p=0.002), and between depressive temperament scores and attention deficit scores (r=0.303, p=0.020). There was no relationship between ADHD subtypes and dominant temperament (p>0.05). CONCLUSION: The most common dominant temperament in the ADHD group was cyclothymic, irritable, and anxious. The positive correlation between WURS scores and cyclothymic temperament suggests that cyclothymic temperament may be a risk factor for adult ADHD.

Association of Age and Response to Methylphenidate HCL Treatment in Adult ADHD: A Proton Magnetic Resonance Spectroscopy Study.

Purpose: This study investigated the age-dependent effects of methylphenidate (MPH) on brain metabolites including choline (Cho), N-acetyl aspartate (NAA) and creatine (Cr) levels in the dorsolateral prefrontal cortex (DLPFC), striatum, cerebellum, and anterior cingulate cortex (ACC) regions of the brain in adult patients with attention deficit hyperactivity disorder (ADHD). Patients and Methods: The study was included 60 patients with ADHD between the ages of 18 and 60 years. The patients were grouped with respect to their ages as follows: 18-24 years, 25-30 years, and 31 and over years. Levels of NAA, Cr and Cho in DLPFC, ACC, cerebellum and striatum were measured with magnetic resonance spectroscopy (MRS). Subjects were then given 10 mg of oral MPH and the same metabolite levels were measured 30 minutes apart. Results: Twelve (20%) of the cases were female and 48 (80%) were male. The age distribution of the cases is as follows: 15 subjects between the ages of 18-24, 26 subjects between the ages of 25-30 and 19 subjects over the age of 30. NAA levels were higher after MPH in the DLPFC of the 18-24 age group (p = 0.016) and in the cerebellum of the 25-30 age group (p = 0.041). No increase in Cho and Cr levels was observed after treatment compared to before (p > 0.05). Conclusion: It is thought that treatment of MPH can be effective on metabolites in different brain regions and this effect can vary upon age adult ADHD patients. After MPH treatment, both the 18-24 age group (in the DLPFC) and the 25-30 age group (in the cerebellum) was detected significantly higher NAA levels compared to pre-treatment levels. This increase in NAA levels suggested that pharmacotherapy, especially at early ages, may be effective on neuronal damage.

Association of adult attention deficit hyperactivity disorder subtypes and response to methylphenidate HCL treatment: A magnetic resonance spectroscopy study.

The effects of methylphenidate (MPH) treatment on N-acetyl aspartate (NAA), choline and creatine are being examined in individuals with different subtypes of attention deficit hyperactivity disorder (ADHD). Sixty ADHD subjects were included into the study aging between 18 and 60 years. Levels of NAA, creatine and choline in anterior cingulate cortex, cerebellum, striatum and dorsolateral prefrontal cortex were measured with magnetic resonance spectroscopy. Then, 10mg oral MPH was given to the subjects and the same metabolite levels were measured after an interval of 30min. Distribution of the patients according to the ADHD subtypes was as follows: 21 of them (35.0%) were in the inattentive type, 11 of them (18.3%) were in the hyperactive type and 28 of them were (46.7%) in the combined type. Changes of brain metabolite levels after MPH were found not to be statistically significantly different between the subtypes. The increase of choline levels after MPH compared to the levels of choline before MPH in striatum in the combined type patients were statistically significant. No clear association was found between ADHD subtypes and changes of brain metabolites with use of MPH in adult ADHD.

Association of SNAP-25 Gene Ddel and Mnll Polymorphisms with Adult Attention Deficit Hyperactivity Disorder.

OBJECTIVE: The synaptosomal-associated protein of 25 kDa (SNAP-25) gene is a presynaptic plasma membrane protein and an integral component of the vesicle docking and fusion machinery mediating secretion of neurotransmitters. Previously, several studies reported association between SNAP-25 and attention deficit hyperactivity disorder (ADHD). We investigated whether these SNAP-25 polymorphisms (MnlI T/G and DdelI T/C) were also associated with ADHD in the Turkish population. METHODS: Our study comprised unrelated 139 subjects who met DSM-IV criteria for ADHD and 73 controls and all were of Turkish origin. Genetic analyses were performed and patients were evaluated with Wender-Utah Rating Scale and Adult ADD/ADHD DSM IV-Based Diagnostic Screening and Rating Scale. RESULTS: SNAP-25 DdelI polymorphism was not associated with ADHD but there was a statistically significant difference between ADHD patients and controls for SNAP-25 MnlI polymorphism. For SNAP-25 MnlI polymorphism patients with G/G genotype of the SNAP-25 gene MnlI polymorphism had higher Wender-Utah scores and higher scores in the 1st and 3rd parts of adult ADD/ADHD Scale. CONCLUSION: We detected a significant association of the MnlI polymorphism in our ADHD sample which was similar to previous findings. Our study also revealed that SNAP-25 MnlI polymorphism was also associated with symptom severity of ADHD. This study is also, the first report on the association of SNAP-25 with ADHD in the Turkish population.